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1 /*
2  * Copyright © 2010 Intel Corporation
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice (including the next
12  * paragraph) shall be included in all copies or substantial portions of the
13  * Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21  * IN THE SOFTWARE.
22  */
23 
24 #include "compiler/glsl/ir.h"
25 #include "brw_fs.h"
26 #include "brw_fs_surface_builder.h"
27 #include "brw_nir.h"
28 
29 using namespace brw;
30 using namespace brw::surface_access;
31 
32 void
emit_nir_code()33 fs_visitor::emit_nir_code()
34 {
35    /* emit the arrays used for inputs and outputs - load/store intrinsics will
36     * be converted to reads/writes of these arrays
37     */
38    nir_setup_outputs();
39    nir_setup_uniforms();
40    nir_emit_system_values();
41 
42    /* get the main function and emit it */
43    nir_foreach_function(function, nir) {
44       assert(strcmp(function->name, "main") == 0);
45       assert(function->impl);
46       nir_emit_impl(function->impl);
47    }
48 }
49 
50 void
nir_setup_outputs()51 fs_visitor::nir_setup_outputs()
52 {
53    if (stage == MESA_SHADER_TESS_CTRL || stage == MESA_SHADER_FRAGMENT)
54       return;
55 
56    unsigned vec4s[VARYING_SLOT_TESS_MAX] = { 0, };
57 
58    /* Calculate the size of output registers in a separate pass, before
59     * allocating them.  With ARB_enhanced_layouts, multiple output variables
60     * may occupy the same slot, but have different type sizes.
61     */
62    nir_foreach_variable(var, &nir->outputs) {
63       const int loc = var->data.driver_location;
64       const unsigned var_vec4s =
65          var->data.compact ? DIV_ROUND_UP(glsl_get_length(var->type), 4)
66                            : type_size_vec4(var->type);
67       vec4s[loc] = MAX2(vec4s[loc], var_vec4s);
68    }
69 
70    nir_foreach_variable(var, &nir->outputs) {
71       const int loc = var->data.driver_location;
72       if (outputs[loc].file == BAD_FILE) {
73          fs_reg reg = bld.vgrf(BRW_REGISTER_TYPE_F, 4 * vec4s[loc]);
74          for (unsigned i = 0; i < vec4s[loc]; i++) {
75             outputs[loc + i] = offset(reg, bld, 4 * i);
76          }
77       }
78    }
79 }
80 
81 void
nir_setup_uniforms()82 fs_visitor::nir_setup_uniforms()
83 {
84    /* Only the first compile gets to set up uniforms. */
85    if (push_constant_loc) {
86       assert(pull_constant_loc);
87       return;
88    }
89 
90    uniforms = nir->num_uniforms / 4;
91 
92    if (stage == MESA_SHADER_COMPUTE) {
93       /* Add a uniform for the thread local id.  It must be the last uniform
94        * on the list.
95        */
96       assert(uniforms == prog_data->nr_params);
97       uint32_t *param = brw_stage_prog_data_add_params(prog_data, 1);
98       *param = BRW_PARAM_BUILTIN_SUBGROUP_ID;
99       subgroup_id = fs_reg(UNIFORM, uniforms++, BRW_REGISTER_TYPE_UD);
100    }
101 }
102 
103 static bool
emit_system_values_block(nir_block * block,fs_visitor * v)104 emit_system_values_block(nir_block *block, fs_visitor *v)
105 {
106    fs_reg *reg;
107 
108    nir_foreach_instr(instr, block) {
109       if (instr->type != nir_instr_type_intrinsic)
110          continue;
111 
112       nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
113       switch (intrin->intrinsic) {
114       case nir_intrinsic_load_vertex_id:
115          unreachable("should be lowered by lower_vertex_id().");
116 
117       case nir_intrinsic_load_vertex_id_zero_base:
118       case nir_intrinsic_load_base_vertex:
119       case nir_intrinsic_load_instance_id:
120       case nir_intrinsic_load_base_instance:
121       case nir_intrinsic_load_draw_id:
122          unreachable("should be lowered by brw_nir_lower_vs_inputs().");
123 
124       case nir_intrinsic_load_invocation_id:
125          if (v->stage == MESA_SHADER_TESS_CTRL)
126             break;
127          assert(v->stage == MESA_SHADER_GEOMETRY);
128          reg = &v->nir_system_values[SYSTEM_VALUE_INVOCATION_ID];
129          if (reg->file == BAD_FILE) {
130             const fs_builder abld = v->bld.annotate("gl_InvocationID", NULL);
131             fs_reg g1(retype(brw_vec8_grf(1, 0), BRW_REGISTER_TYPE_UD));
132             fs_reg iid = abld.vgrf(BRW_REGISTER_TYPE_UD, 1);
133             abld.SHR(iid, g1, brw_imm_ud(27u));
134             *reg = iid;
135          }
136          break;
137 
138       case nir_intrinsic_load_sample_pos:
139          assert(v->stage == MESA_SHADER_FRAGMENT);
140          reg = &v->nir_system_values[SYSTEM_VALUE_SAMPLE_POS];
141          if (reg->file == BAD_FILE)
142             *reg = *v->emit_samplepos_setup();
143          break;
144 
145       case nir_intrinsic_load_sample_id:
146          assert(v->stage == MESA_SHADER_FRAGMENT);
147          reg = &v->nir_system_values[SYSTEM_VALUE_SAMPLE_ID];
148          if (reg->file == BAD_FILE)
149             *reg = *v->emit_sampleid_setup();
150          break;
151 
152       case nir_intrinsic_load_sample_mask_in:
153          assert(v->stage == MESA_SHADER_FRAGMENT);
154          assert(v->devinfo->gen >= 7);
155          reg = &v->nir_system_values[SYSTEM_VALUE_SAMPLE_MASK_IN];
156          if (reg->file == BAD_FILE)
157             *reg = *v->emit_samplemaskin_setup();
158          break;
159 
160       case nir_intrinsic_load_work_group_id:
161          assert(v->stage == MESA_SHADER_COMPUTE);
162          reg = &v->nir_system_values[SYSTEM_VALUE_WORK_GROUP_ID];
163          if (reg->file == BAD_FILE)
164             *reg = *v->emit_cs_work_group_id_setup();
165          break;
166 
167       case nir_intrinsic_load_helper_invocation:
168          assert(v->stage == MESA_SHADER_FRAGMENT);
169          reg = &v->nir_system_values[SYSTEM_VALUE_HELPER_INVOCATION];
170          if (reg->file == BAD_FILE) {
171             const fs_builder abld =
172                v->bld.annotate("gl_HelperInvocation", NULL);
173 
174             /* On Gen6+ (gl_HelperInvocation is only exposed on Gen7+) the
175              * pixel mask is in g1.7 of the thread payload.
176              *
177              * We move the per-channel pixel enable bit to the low bit of each
178              * channel by shifting the byte containing the pixel mask by the
179              * vector immediate 0x76543210UV.
180              *
181              * The region of <1,8,0> reads only 1 byte (the pixel masks for
182              * subspans 0 and 1) in SIMD8 and an additional byte (the pixel
183              * masks for 2 and 3) in SIMD16.
184              */
185             fs_reg shifted = abld.vgrf(BRW_REGISTER_TYPE_UW, 1);
186             abld.SHR(shifted,
187                      stride(byte_offset(retype(brw_vec1_grf(1, 0),
188                                                BRW_REGISTER_TYPE_UB), 28),
189                             1, 8, 0),
190                      brw_imm_v(0x76543210));
191 
192             /* A set bit in the pixel mask means the channel is enabled, but
193              * that is the opposite of gl_HelperInvocation so we need to invert
194              * the mask.
195              *
196              * The negate source-modifier bit of logical instructions on Gen8+
197              * performs 1's complement negation, so we can use that instead of
198              * a NOT instruction.
199              */
200             fs_reg inverted = negate(shifted);
201             if (v->devinfo->gen < 8) {
202                inverted = abld.vgrf(BRW_REGISTER_TYPE_UW);
203                abld.NOT(inverted, shifted);
204             }
205 
206             /* We then resolve the 0/1 result to 0/~0 boolean values by ANDing
207              * with 1 and negating.
208              */
209             fs_reg anded = abld.vgrf(BRW_REGISTER_TYPE_UD, 1);
210             abld.AND(anded, inverted, brw_imm_uw(1));
211 
212             fs_reg dst = abld.vgrf(BRW_REGISTER_TYPE_D, 1);
213             abld.MOV(dst, negate(retype(anded, BRW_REGISTER_TYPE_D)));
214             *reg = dst;
215          }
216          break;
217 
218       default:
219          break;
220       }
221    }
222 
223    return true;
224 }
225 
226 void
nir_emit_system_values()227 fs_visitor::nir_emit_system_values()
228 {
229    nir_system_values = ralloc_array(mem_ctx, fs_reg, SYSTEM_VALUE_MAX);
230    for (unsigned i = 0; i < SYSTEM_VALUE_MAX; i++) {
231       nir_system_values[i] = fs_reg();
232    }
233 
234    /* Always emit SUBGROUP_INVOCATION.  Dead code will clean it up if we
235     * never end up using it.
236     */
237    {
238       const fs_builder abld = bld.annotate("gl_SubgroupInvocation", NULL);
239       fs_reg &reg = nir_system_values[SYSTEM_VALUE_SUBGROUP_INVOCATION];
240       reg = abld.vgrf(BRW_REGISTER_TYPE_UW);
241 
242       const fs_builder allbld8 = abld.group(8, 0).exec_all();
243       allbld8.MOV(reg, brw_imm_v(0x76543210));
244       if (dispatch_width > 8)
245          allbld8.ADD(byte_offset(reg, 16), reg, brw_imm_uw(8u));
246       if (dispatch_width > 16) {
247          const fs_builder allbld16 = abld.group(16, 0).exec_all();
248          allbld16.ADD(byte_offset(reg, 32), reg, brw_imm_uw(16u));
249       }
250    }
251 
252    nir_foreach_function(function, nir) {
253       assert(strcmp(function->name, "main") == 0);
254       assert(function->impl);
255       nir_foreach_block(block, function->impl) {
256          emit_system_values_block(block, this);
257       }
258    }
259 }
260 
261 /*
262  * Returns a type based on a reference_type (word, float, half-float) and a
263  * given bit_size.
264  *
265  * Reference BRW_REGISTER_TYPE are HF,F,DF,W,D,UW,UD.
266  *
267  * @FIXME: 64-bit return types are always DF on integer types to maintain
268  * compability with uses of DF previously to the introduction of int64
269  * support.
270  */
271 static brw_reg_type
brw_reg_type_from_bit_size(const unsigned bit_size,const brw_reg_type reference_type)272 brw_reg_type_from_bit_size(const unsigned bit_size,
273                            const brw_reg_type reference_type)
274 {
275    switch(reference_type) {
276    case BRW_REGISTER_TYPE_HF:
277    case BRW_REGISTER_TYPE_F:
278    case BRW_REGISTER_TYPE_DF:
279       switch(bit_size) {
280       case 16:
281          return BRW_REGISTER_TYPE_HF;
282       case 32:
283          return BRW_REGISTER_TYPE_F;
284       case 64:
285          return BRW_REGISTER_TYPE_DF;
286       default:
287          unreachable("Invalid bit size");
288       }
289    case BRW_REGISTER_TYPE_W:
290    case BRW_REGISTER_TYPE_D:
291    case BRW_REGISTER_TYPE_Q:
292       switch(bit_size) {
293       case 16:
294          return BRW_REGISTER_TYPE_W;
295       case 32:
296          return BRW_REGISTER_TYPE_D;
297       case 64:
298          return BRW_REGISTER_TYPE_Q;
299       default:
300          unreachable("Invalid bit size");
301       }
302    case BRW_REGISTER_TYPE_UW:
303    case BRW_REGISTER_TYPE_UD:
304    case BRW_REGISTER_TYPE_UQ:
305       switch(bit_size) {
306       case 16:
307          return BRW_REGISTER_TYPE_UW;
308       case 32:
309          return BRW_REGISTER_TYPE_UD;
310       case 64:
311          return BRW_REGISTER_TYPE_UQ;
312       default:
313          unreachable("Invalid bit size");
314       }
315    default:
316       unreachable("Unknown type");
317    }
318 }
319 
320 void
nir_emit_impl(nir_function_impl * impl)321 fs_visitor::nir_emit_impl(nir_function_impl *impl)
322 {
323    nir_locals = ralloc_array(mem_ctx, fs_reg, impl->reg_alloc);
324    for (unsigned i = 0; i < impl->reg_alloc; i++) {
325       nir_locals[i] = fs_reg();
326    }
327 
328    foreach_list_typed(nir_register, reg, node, &impl->registers) {
329       unsigned array_elems =
330          reg->num_array_elems == 0 ? 1 : reg->num_array_elems;
331       unsigned size = array_elems * reg->num_components;
332       const brw_reg_type reg_type =
333          brw_reg_type_from_bit_size(reg->bit_size, BRW_REGISTER_TYPE_F);
334       nir_locals[reg->index] = bld.vgrf(reg_type, size);
335    }
336 
337    nir_ssa_values = reralloc(mem_ctx, nir_ssa_values, fs_reg,
338                              impl->ssa_alloc);
339 
340    nir_emit_cf_list(&impl->body);
341 }
342 
343 void
nir_emit_cf_list(exec_list * list)344 fs_visitor::nir_emit_cf_list(exec_list *list)
345 {
346    exec_list_validate(list);
347    foreach_list_typed(nir_cf_node, node, node, list) {
348       switch (node->type) {
349       case nir_cf_node_if:
350          nir_emit_if(nir_cf_node_as_if(node));
351          break;
352 
353       case nir_cf_node_loop:
354          nir_emit_loop(nir_cf_node_as_loop(node));
355          break;
356 
357       case nir_cf_node_block:
358          nir_emit_block(nir_cf_node_as_block(node));
359          break;
360 
361       default:
362          unreachable("Invalid CFG node block");
363       }
364    }
365 }
366 
367 void
nir_emit_if(nir_if * if_stmt)368 fs_visitor::nir_emit_if(nir_if *if_stmt)
369 {
370    /* first, put the condition into f0 */
371    fs_inst *inst = bld.MOV(bld.null_reg_d(),
372                             retype(get_nir_src(if_stmt->condition),
373                                    BRW_REGISTER_TYPE_D));
374    inst->conditional_mod = BRW_CONDITIONAL_NZ;
375 
376    bld.IF(BRW_PREDICATE_NORMAL);
377 
378    nir_emit_cf_list(&if_stmt->then_list);
379 
380    /* note: if the else is empty, dead CF elimination will remove it */
381    bld.emit(BRW_OPCODE_ELSE);
382 
383    nir_emit_cf_list(&if_stmt->else_list);
384 
385    bld.emit(BRW_OPCODE_ENDIF);
386 }
387 
388 void
nir_emit_loop(nir_loop * loop)389 fs_visitor::nir_emit_loop(nir_loop *loop)
390 {
391    bld.emit(BRW_OPCODE_DO);
392 
393    nir_emit_cf_list(&loop->body);
394 
395    bld.emit(BRW_OPCODE_WHILE);
396 }
397 
398 void
nir_emit_block(nir_block * block)399 fs_visitor::nir_emit_block(nir_block *block)
400 {
401    nir_foreach_instr(instr, block) {
402       nir_emit_instr(instr);
403    }
404 }
405 
406 void
nir_emit_instr(nir_instr * instr)407 fs_visitor::nir_emit_instr(nir_instr *instr)
408 {
409    const fs_builder abld = bld.annotate(NULL, instr);
410 
411    switch (instr->type) {
412    case nir_instr_type_alu:
413       nir_emit_alu(abld, nir_instr_as_alu(instr));
414       break;
415 
416    case nir_instr_type_intrinsic:
417       switch (stage) {
418       case MESA_SHADER_VERTEX:
419          nir_emit_vs_intrinsic(abld, nir_instr_as_intrinsic(instr));
420          break;
421       case MESA_SHADER_TESS_CTRL:
422          nir_emit_tcs_intrinsic(abld, nir_instr_as_intrinsic(instr));
423          break;
424       case MESA_SHADER_TESS_EVAL:
425          nir_emit_tes_intrinsic(abld, nir_instr_as_intrinsic(instr));
426          break;
427       case MESA_SHADER_GEOMETRY:
428          nir_emit_gs_intrinsic(abld, nir_instr_as_intrinsic(instr));
429          break;
430       case MESA_SHADER_FRAGMENT:
431          nir_emit_fs_intrinsic(abld, nir_instr_as_intrinsic(instr));
432          break;
433       case MESA_SHADER_COMPUTE:
434          nir_emit_cs_intrinsic(abld, nir_instr_as_intrinsic(instr));
435          break;
436       default:
437          unreachable("unsupported shader stage");
438       }
439       break;
440 
441    case nir_instr_type_tex:
442       nir_emit_texture(abld, nir_instr_as_tex(instr));
443       break;
444 
445    case nir_instr_type_load_const:
446       nir_emit_load_const(abld, nir_instr_as_load_const(instr));
447       break;
448 
449    case nir_instr_type_ssa_undef:
450       /* We create a new VGRF for undefs on every use (by handling
451        * them in get_nir_src()), rather than for each definition.
452        * This helps register coalescing eliminate MOVs from undef.
453        */
454       break;
455 
456    case nir_instr_type_jump:
457       nir_emit_jump(abld, nir_instr_as_jump(instr));
458       break;
459 
460    default:
461       unreachable("unknown instruction type");
462    }
463 }
464 
465 /**
466  * Recognizes a parent instruction of nir_op_extract_* and changes the type to
467  * match instr.
468  */
469 bool
optimize_extract_to_float(nir_alu_instr * instr,const fs_reg & result)470 fs_visitor::optimize_extract_to_float(nir_alu_instr *instr,
471                                       const fs_reg &result)
472 {
473    if (!instr->src[0].src.is_ssa ||
474        !instr->src[0].src.ssa->parent_instr)
475       return false;
476 
477    if (instr->src[0].src.ssa->parent_instr->type != nir_instr_type_alu)
478       return false;
479 
480    nir_alu_instr *src0 =
481       nir_instr_as_alu(instr->src[0].src.ssa->parent_instr);
482 
483    if (src0->op != nir_op_extract_u8 && src0->op != nir_op_extract_u16 &&
484        src0->op != nir_op_extract_i8 && src0->op != nir_op_extract_i16)
485       return false;
486 
487    nir_const_value *element = nir_src_as_const_value(src0->src[1].src);
488    assert(element != NULL);
489 
490    /* Element type to extract.*/
491    const brw_reg_type type = brw_int_type(
492       src0->op == nir_op_extract_u16 || src0->op == nir_op_extract_i16 ? 2 : 1,
493       src0->op == nir_op_extract_i16 || src0->op == nir_op_extract_i8);
494 
495    fs_reg op0 = get_nir_src(src0->src[0].src);
496    op0.type = brw_type_for_nir_type(devinfo,
497       (nir_alu_type)(nir_op_infos[src0->op].input_types[0] |
498                      nir_src_bit_size(src0->src[0].src)));
499    op0 = offset(op0, bld, src0->src[0].swizzle[0]);
500 
501    set_saturate(instr->dest.saturate,
502                 bld.MOV(result, subscript(op0, type, element->u32[0])));
503    return true;
504 }
505 
506 bool
optimize_frontfacing_ternary(nir_alu_instr * instr,const fs_reg & result)507 fs_visitor::optimize_frontfacing_ternary(nir_alu_instr *instr,
508                                          const fs_reg &result)
509 {
510    if (!instr->src[0].src.is_ssa ||
511        instr->src[0].src.ssa->parent_instr->type != nir_instr_type_intrinsic)
512       return false;
513 
514    nir_intrinsic_instr *src0 =
515       nir_instr_as_intrinsic(instr->src[0].src.ssa->parent_instr);
516 
517    if (src0->intrinsic != nir_intrinsic_load_front_face)
518       return false;
519 
520    nir_const_value *value1 = nir_src_as_const_value(instr->src[1].src);
521    if (!value1 || fabsf(value1->f32[0]) != 1.0f)
522       return false;
523 
524    nir_const_value *value2 = nir_src_as_const_value(instr->src[2].src);
525    if (!value2 || fabsf(value2->f32[0]) != 1.0f)
526       return false;
527 
528    fs_reg tmp = vgrf(glsl_type::int_type);
529 
530    if (devinfo->gen >= 6) {
531       /* Bit 15 of g0.0 is 0 if the polygon is front facing. */
532       fs_reg g0 = fs_reg(retype(brw_vec1_grf(0, 0), BRW_REGISTER_TYPE_W));
533 
534       /* For (gl_FrontFacing ? 1.0 : -1.0), emit:
535        *
536        *    or(8)  tmp.1<2>W  g0.0<0,1,0>W  0x00003f80W
537        *    and(8) dst<1>D    tmp<8,8,1>D   0xbf800000D
538        *
539        * and negate g0.0<0,1,0>W for (gl_FrontFacing ? -1.0 : 1.0).
540        *
541        * This negation looks like it's safe in practice, because bits 0:4 will
542        * surely be TRIANGLES
543        */
544 
545       if (value1->f32[0] == -1.0f) {
546          g0.negate = true;
547       }
548 
549       bld.OR(subscript(tmp, BRW_REGISTER_TYPE_W, 1),
550              g0, brw_imm_uw(0x3f80));
551    } else {
552       /* Bit 31 of g1.6 is 0 if the polygon is front facing. */
553       fs_reg g1_6 = fs_reg(retype(brw_vec1_grf(1, 6), BRW_REGISTER_TYPE_D));
554 
555       /* For (gl_FrontFacing ? 1.0 : -1.0), emit:
556        *
557        *    or(8)  tmp<1>D  g1.6<0,1,0>D  0x3f800000D
558        *    and(8) dst<1>D  tmp<8,8,1>D   0xbf800000D
559        *
560        * and negate g1.6<0,1,0>D for (gl_FrontFacing ? -1.0 : 1.0).
561        *
562        * This negation looks like it's safe in practice, because bits 0:4 will
563        * surely be TRIANGLES
564        */
565 
566       if (value1->f32[0] == -1.0f) {
567          g1_6.negate = true;
568       }
569 
570       bld.OR(tmp, g1_6, brw_imm_d(0x3f800000));
571    }
572    bld.AND(retype(result, BRW_REGISTER_TYPE_D), tmp, brw_imm_d(0xbf800000));
573 
574    return true;
575 }
576 
577 static void
emit_find_msb_using_lzd(const fs_builder & bld,const fs_reg & result,const fs_reg & src,bool is_signed)578 emit_find_msb_using_lzd(const fs_builder &bld,
579                         const fs_reg &result,
580                         const fs_reg &src,
581                         bool is_signed)
582 {
583    fs_inst *inst;
584    fs_reg temp = src;
585 
586    if (is_signed) {
587       /* LZD of an absolute value source almost always does the right
588        * thing.  There are two problem values:
589        *
590        * * 0x80000000.  Since abs(0x80000000) == 0x80000000, LZD returns
591        *   0.  However, findMSB(int(0x80000000)) == 30.
592        *
593        * * 0xffffffff.  Since abs(0xffffffff) == 1, LZD returns
594        *   31.  Section 8.8 (Integer Functions) of the GLSL 4.50 spec says:
595        *
596        *    For a value of zero or negative one, -1 will be returned.
597        *
598        * * Negative powers of two.  LZD(abs(-(1<<x))) returns x, but
599        *   findMSB(-(1<<x)) should return x-1.
600        *
601        * For all negative number cases, including 0x80000000 and
602        * 0xffffffff, the correct value is obtained from LZD if instead of
603        * negating the (already negative) value the logical-not is used.  A
604        * conditonal logical-not can be achieved in two instructions.
605        */
606       temp = bld.vgrf(BRW_REGISTER_TYPE_D);
607 
608       bld.ASR(temp, src, brw_imm_d(31));
609       bld.XOR(temp, temp, src);
610    }
611 
612    bld.LZD(retype(result, BRW_REGISTER_TYPE_UD),
613            retype(temp, BRW_REGISTER_TYPE_UD));
614 
615    /* LZD counts from the MSB side, while GLSL's findMSB() wants the count
616     * from the LSB side. Subtract the result from 31 to convert the MSB
617     * count into an LSB count.  If no bits are set, LZD will return 32.
618     * 31-32 = -1, which is exactly what findMSB() is supposed to return.
619     */
620    inst = bld.ADD(result, retype(result, BRW_REGISTER_TYPE_D), brw_imm_d(31));
621    inst->src[0].negate = true;
622 }
623 
624 static brw_rnd_mode
brw_rnd_mode_from_nir_op(const nir_op op)625 brw_rnd_mode_from_nir_op (const nir_op op) {
626    switch (op) {
627    case nir_op_f2f16_rtz:
628       return BRW_RND_MODE_RTZ;
629    case nir_op_f2f16_rtne:
630       return BRW_RND_MODE_RTNE;
631    default:
632       unreachable("Operation doesn't support rounding mode");
633    }
634 }
635 
636 void
nir_emit_alu(const fs_builder & bld,nir_alu_instr * instr)637 fs_visitor::nir_emit_alu(const fs_builder &bld, nir_alu_instr *instr)
638 {
639    struct brw_wm_prog_key *fs_key = (struct brw_wm_prog_key *) this->key;
640    fs_inst *inst;
641 
642    fs_reg result = get_nir_dest(instr->dest.dest);
643    result.type = brw_type_for_nir_type(devinfo,
644       (nir_alu_type)(nir_op_infos[instr->op].output_type |
645                      nir_dest_bit_size(instr->dest.dest)));
646 
647    fs_reg op[4];
648    for (unsigned i = 0; i < nir_op_infos[instr->op].num_inputs; i++) {
649       op[i] = get_nir_src(instr->src[i].src);
650       op[i].type = brw_type_for_nir_type(devinfo,
651          (nir_alu_type)(nir_op_infos[instr->op].input_types[i] |
652                         nir_src_bit_size(instr->src[i].src)));
653       op[i].abs = instr->src[i].abs;
654       op[i].negate = instr->src[i].negate;
655    }
656 
657    /* We get a bunch of mov's out of the from_ssa pass and they may still
658     * be vectorized.  We'll handle them as a special-case.  We'll also
659     * handle vecN here because it's basically the same thing.
660     */
661    switch (instr->op) {
662    case nir_op_imov:
663    case nir_op_fmov:
664    case nir_op_vec2:
665    case nir_op_vec3:
666    case nir_op_vec4: {
667       fs_reg temp = result;
668       bool need_extra_copy = false;
669       for (unsigned i = 0; i < nir_op_infos[instr->op].num_inputs; i++) {
670          if (!instr->src[i].src.is_ssa &&
671              instr->dest.dest.reg.reg == instr->src[i].src.reg.reg) {
672             need_extra_copy = true;
673             temp = bld.vgrf(result.type, 4);
674             break;
675          }
676       }
677 
678       for (unsigned i = 0; i < 4; i++) {
679          if (!(instr->dest.write_mask & (1 << i)))
680             continue;
681 
682          if (instr->op == nir_op_imov || instr->op == nir_op_fmov) {
683             inst = bld.MOV(offset(temp, bld, i),
684                            offset(op[0], bld, instr->src[0].swizzle[i]));
685          } else {
686             inst = bld.MOV(offset(temp, bld, i),
687                            offset(op[i], bld, instr->src[i].swizzle[0]));
688          }
689          inst->saturate = instr->dest.saturate;
690       }
691 
692       /* In this case the source and destination registers were the same,
693        * so we need to insert an extra set of moves in order to deal with
694        * any swizzling.
695        */
696       if (need_extra_copy) {
697          for (unsigned i = 0; i < 4; i++) {
698             if (!(instr->dest.write_mask & (1 << i)))
699                continue;
700 
701             bld.MOV(offset(result, bld, i), offset(temp, bld, i));
702          }
703       }
704       return;
705    }
706    default:
707       break;
708    }
709 
710    /* At this point, we have dealt with any instruction that operates on
711     * more than a single channel.  Therefore, we can just adjust the source
712     * and destination registers for that channel and emit the instruction.
713     */
714    unsigned channel = 0;
715    if (nir_op_infos[instr->op].output_size == 0) {
716       /* Since NIR is doing the scalarizing for us, we should only ever see
717        * vectorized operations with a single channel.
718        */
719       assert(_mesa_bitcount(instr->dest.write_mask) == 1);
720       channel = ffs(instr->dest.write_mask) - 1;
721 
722       result = offset(result, bld, channel);
723    }
724 
725    for (unsigned i = 0; i < nir_op_infos[instr->op].num_inputs; i++) {
726       assert(nir_op_infos[instr->op].input_sizes[i] < 2);
727       op[i] = offset(op[i], bld, instr->src[i].swizzle[channel]);
728    }
729 
730    switch (instr->op) {
731    case nir_op_i2f32:
732    case nir_op_u2f32:
733       if (optimize_extract_to_float(instr, result))
734          return;
735       inst = bld.MOV(result, op[0]);
736       inst->saturate = instr->dest.saturate;
737       break;
738 
739    case nir_op_f2f16_rtne:
740    case nir_op_f2f16_rtz:
741       bld.emit(SHADER_OPCODE_RND_MODE, bld.null_reg_ud(),
742                brw_imm_d(brw_rnd_mode_from_nir_op(instr->op)));
743       /* fallthrough */
744 
745       /* In theory, it would be better to use BRW_OPCODE_F32TO16. Depending
746        * on the HW gen, it is a special hw opcode or just a MOV, and
747        * brw_F32TO16 (at brw_eu_emit) would do the work to chose.
748        *
749        * But if we want to use that opcode, we need to provide support on
750        * different optimizations and lowerings. As right now HF support is
751        * only for gen8+, it will be better to use directly the MOV, and use
752        * BRW_OPCODE_F32TO16 when/if we work for HF support on gen7.
753        */
754 
755    case nir_op_f2f16_undef:
756    case nir_op_i2i16:
757    case nir_op_u2u16: {
758       /* TODO: Fixing aligment rules for conversions from 32-bits to
759        * 16-bit types should be moved to lower_conversions
760        */
761       fs_reg tmp = bld.vgrf(op[0].type, 1);
762       tmp = subscript(tmp, result.type, 0);
763       inst = bld.MOV(tmp, op[0]);
764       inst->saturate = instr->dest.saturate;
765       inst = bld.MOV(result, tmp);
766       inst->saturate = instr->dest.saturate;
767       break;
768    }
769 
770    case nir_op_f2f64:
771    case nir_op_f2i64:
772    case nir_op_f2u64:
773    case nir_op_i2f64:
774    case nir_op_i2i64:
775    case nir_op_u2f64:
776    case nir_op_u2u64:
777       /* CHV PRM, vol07, 3D Media GPGPU Engine, Register Region Restrictions:
778        *
779        *    "When source or destination is 64b (...), regioning in Align1
780        *     must follow these rules:
781        *
782        *     1. Source and destination horizontal stride must be aligned to
783        *        the same qword.
784        *     (...)"
785        *
786        * This means that 32-bit to 64-bit conversions need to have the 32-bit
787        * data elements aligned to 64-bit. This restriction does not apply to
788        * BDW and later.
789        */
790       if (nir_dest_bit_size(instr->dest.dest) == 64 &&
791           nir_src_bit_size(instr->src[0].src) == 32 &&
792           (devinfo->is_cherryview || gen_device_info_is_9lp(devinfo))) {
793          fs_reg tmp = bld.vgrf(result.type, 1);
794          tmp = subscript(tmp, op[0].type, 0);
795          inst = bld.MOV(tmp, op[0]);
796          inst = bld.MOV(result, tmp);
797          inst->saturate = instr->dest.saturate;
798          break;
799       }
800       /* fallthrough */
801    case nir_op_f2f32:
802    case nir_op_f2i32:
803    case nir_op_f2u32:
804    case nir_op_i2i32:
805    case nir_op_u2u32:
806       inst = bld.MOV(result, op[0]);
807       inst->saturate = instr->dest.saturate;
808       break;
809 
810    case nir_op_fsign: {
811       if (op[0].abs) {
812          /* Straightforward since the source can be assumed to be
813           * non-negative.
814           */
815          set_condmod(BRW_CONDITIONAL_NZ, bld.MOV(result, op[0]));
816          set_predicate(BRW_PREDICATE_NORMAL, bld.MOV(result, brw_imm_f(1.0f)));
817 
818       } else if (type_sz(op[0].type) < 8) {
819          /* AND(val, 0x80000000) gives the sign bit.
820           *
821           * Predicated OR ORs 1.0 (0x3f800000) with the sign bit if val is not
822           * zero.
823           */
824          bld.CMP(bld.null_reg_f(), op[0], brw_imm_f(0.0f), BRW_CONDITIONAL_NZ);
825 
826          fs_reg result_int = retype(result, BRW_REGISTER_TYPE_UD);
827          op[0].type = BRW_REGISTER_TYPE_UD;
828          result.type = BRW_REGISTER_TYPE_UD;
829          bld.AND(result_int, op[0], brw_imm_ud(0x80000000u));
830 
831          inst = bld.OR(result_int, result_int, brw_imm_ud(0x3f800000u));
832          inst->predicate = BRW_PREDICATE_NORMAL;
833          if (instr->dest.saturate) {
834             inst = bld.MOV(result, result);
835             inst->saturate = true;
836          }
837       } else {
838          /* For doubles we do the same but we need to consider:
839           *
840           * - 2-src instructions can't operate with 64-bit immediates
841           * - The sign is encoded in the high 32-bit of each DF
842           * - We need to produce a DF result.
843           */
844 
845          fs_reg zero = vgrf(glsl_type::double_type);
846          bld.MOV(zero, setup_imm_df(bld, 0.0));
847          bld.CMP(bld.null_reg_df(), op[0], zero, BRW_CONDITIONAL_NZ);
848 
849          bld.MOV(result, zero);
850 
851          fs_reg r = subscript(result, BRW_REGISTER_TYPE_UD, 1);
852          bld.AND(r, subscript(op[0], BRW_REGISTER_TYPE_UD, 1),
853                  brw_imm_ud(0x80000000u));
854 
855          set_predicate(BRW_PREDICATE_NORMAL,
856                        bld.OR(r, r, brw_imm_ud(0x3ff00000u)));
857 
858          if (instr->dest.saturate) {
859             inst = bld.MOV(result, result);
860             inst->saturate = true;
861          }
862       }
863       break;
864    }
865 
866    case nir_op_isign:
867       /*  ASR(val, 31) -> negative val generates 0xffffffff (signed -1).
868        *               -> non-negative val generates 0x00000000.
869        *  Predicated OR sets 1 if val is positive.
870        */
871       assert(nir_dest_bit_size(instr->dest.dest) < 64);
872       bld.CMP(bld.null_reg_d(), op[0], brw_imm_d(0), BRW_CONDITIONAL_G);
873       bld.ASR(result, op[0], brw_imm_d(31));
874       inst = bld.OR(result, result, brw_imm_d(1));
875       inst->predicate = BRW_PREDICATE_NORMAL;
876       break;
877 
878    case nir_op_frcp:
879       inst = bld.emit(SHADER_OPCODE_RCP, result, op[0]);
880       inst->saturate = instr->dest.saturate;
881       break;
882 
883    case nir_op_fexp2:
884       inst = bld.emit(SHADER_OPCODE_EXP2, result, op[0]);
885       inst->saturate = instr->dest.saturate;
886       break;
887 
888    case nir_op_flog2:
889       inst = bld.emit(SHADER_OPCODE_LOG2, result, op[0]);
890       inst->saturate = instr->dest.saturate;
891       break;
892 
893    case nir_op_fsin:
894       inst = bld.emit(SHADER_OPCODE_SIN, result, op[0]);
895       inst->saturate = instr->dest.saturate;
896       break;
897 
898    case nir_op_fcos:
899       inst = bld.emit(SHADER_OPCODE_COS, result, op[0]);
900       inst->saturate = instr->dest.saturate;
901       break;
902 
903    case nir_op_fddx:
904       if (fs_key->high_quality_derivatives) {
905          inst = bld.emit(FS_OPCODE_DDX_FINE, result, op[0]);
906       } else {
907          inst = bld.emit(FS_OPCODE_DDX_COARSE, result, op[0]);
908       }
909       inst->saturate = instr->dest.saturate;
910       break;
911    case nir_op_fddx_fine:
912       inst = bld.emit(FS_OPCODE_DDX_FINE, result, op[0]);
913       inst->saturate = instr->dest.saturate;
914       break;
915    case nir_op_fddx_coarse:
916       inst = bld.emit(FS_OPCODE_DDX_COARSE, result, op[0]);
917       inst->saturate = instr->dest.saturate;
918       break;
919    case nir_op_fddy:
920       if (fs_key->high_quality_derivatives) {
921          inst = bld.emit(FS_OPCODE_DDY_FINE, result, op[0]);
922       } else {
923          inst = bld.emit(FS_OPCODE_DDY_COARSE, result, op[0]);
924       }
925       inst->saturate = instr->dest.saturate;
926       break;
927    case nir_op_fddy_fine:
928       inst = bld.emit(FS_OPCODE_DDY_FINE, result, op[0]);
929       inst->saturate = instr->dest.saturate;
930       break;
931    case nir_op_fddy_coarse:
932       inst = bld.emit(FS_OPCODE_DDY_COARSE, result, op[0]);
933       inst->saturate = instr->dest.saturate;
934       break;
935 
936    case nir_op_iadd:
937    case nir_op_fadd:
938       inst = bld.ADD(result, op[0], op[1]);
939       inst->saturate = instr->dest.saturate;
940       break;
941 
942    case nir_op_fmul:
943       inst = bld.MUL(result, op[0], op[1]);
944       inst->saturate = instr->dest.saturate;
945       break;
946 
947    case nir_op_imul:
948       assert(nir_dest_bit_size(instr->dest.dest) < 64);
949       bld.MUL(result, op[0], op[1]);
950       break;
951 
952    case nir_op_imul_high:
953    case nir_op_umul_high:
954       assert(nir_dest_bit_size(instr->dest.dest) < 64);
955       bld.emit(SHADER_OPCODE_MULH, result, op[0], op[1]);
956       break;
957 
958    case nir_op_idiv:
959    case nir_op_udiv:
960       assert(nir_dest_bit_size(instr->dest.dest) < 64);
961       bld.emit(SHADER_OPCODE_INT_QUOTIENT, result, op[0], op[1]);
962       break;
963 
964    case nir_op_uadd_carry:
965       unreachable("Should have been lowered by carry_to_arith().");
966 
967    case nir_op_usub_borrow:
968       unreachable("Should have been lowered by borrow_to_arith().");
969 
970    case nir_op_umod:
971    case nir_op_irem:
972       /* According to the sign table for INT DIV in the Ivy Bridge PRM, it
973        * appears that our hardware just does the right thing for signed
974        * remainder.
975        */
976       assert(nir_dest_bit_size(instr->dest.dest) < 64);
977       bld.emit(SHADER_OPCODE_INT_REMAINDER, result, op[0], op[1]);
978       break;
979 
980    case nir_op_imod: {
981       /* Get a regular C-style remainder.  If a % b == 0, set the predicate. */
982       bld.emit(SHADER_OPCODE_INT_REMAINDER, result, op[0], op[1]);
983 
984       /* Math instructions don't support conditional mod */
985       inst = bld.MOV(bld.null_reg_d(), result);
986       inst->conditional_mod = BRW_CONDITIONAL_NZ;
987 
988       /* Now, we need to determine if signs of the sources are different.
989        * When we XOR the sources, the top bit is 0 if they are the same and 1
990        * if they are different.  We can then use a conditional modifier to
991        * turn that into a predicate.  This leads us to an XOR.l instruction.
992        *
993        * Technically, according to the PRM, you're not allowed to use .l on a
994        * XOR instruction.  However, emperical experiments and Curro's reading
995        * of the simulator source both indicate that it's safe.
996        */
997       fs_reg tmp = bld.vgrf(BRW_REGISTER_TYPE_D);
998       inst = bld.XOR(tmp, op[0], op[1]);
999       inst->predicate = BRW_PREDICATE_NORMAL;
1000       inst->conditional_mod = BRW_CONDITIONAL_L;
1001 
1002       /* If the result of the initial remainder operation is non-zero and the
1003        * two sources have different signs, add in a copy of op[1] to get the
1004        * final integer modulus value.
1005        */
1006       inst = bld.ADD(result, result, op[1]);
1007       inst->predicate = BRW_PREDICATE_NORMAL;
1008       break;
1009    }
1010 
1011    case nir_op_flt:
1012    case nir_op_fge:
1013    case nir_op_feq:
1014    case nir_op_fne: {
1015       fs_reg dest = result;
1016       if (nir_src_bit_size(instr->src[0].src) > 32) {
1017          dest = bld.vgrf(BRW_REGISTER_TYPE_DF, 1);
1018       }
1019       brw_conditional_mod cond;
1020       switch (instr->op) {
1021       case nir_op_flt:
1022          cond = BRW_CONDITIONAL_L;
1023          break;
1024       case nir_op_fge:
1025          cond = BRW_CONDITIONAL_GE;
1026          break;
1027       case nir_op_feq:
1028          cond = BRW_CONDITIONAL_Z;
1029          break;
1030       case nir_op_fne:
1031          cond = BRW_CONDITIONAL_NZ;
1032          break;
1033       default:
1034          unreachable("bad opcode");
1035       }
1036       bld.CMP(dest, op[0], op[1], cond);
1037       if (nir_src_bit_size(instr->src[0].src) > 32) {
1038          bld.MOV(result, subscript(dest, BRW_REGISTER_TYPE_UD, 0));
1039       }
1040       break;
1041    }
1042 
1043    case nir_op_ilt:
1044    case nir_op_ult:
1045    case nir_op_ige:
1046    case nir_op_uge:
1047    case nir_op_ieq:
1048    case nir_op_ine: {
1049       fs_reg dest = result;
1050       if (nir_src_bit_size(instr->src[0].src) > 32) {
1051          dest = bld.vgrf(BRW_REGISTER_TYPE_UQ, 1);
1052       }
1053 
1054       brw_conditional_mod cond;
1055       switch (instr->op) {
1056       case nir_op_ilt:
1057       case nir_op_ult:
1058          cond = BRW_CONDITIONAL_L;
1059          break;
1060       case nir_op_ige:
1061       case nir_op_uge:
1062          cond = BRW_CONDITIONAL_GE;
1063          break;
1064       case nir_op_ieq:
1065          cond = BRW_CONDITIONAL_Z;
1066          break;
1067       case nir_op_ine:
1068          cond = BRW_CONDITIONAL_NZ;
1069          break;
1070       default:
1071          unreachable("bad opcode");
1072       }
1073       bld.CMP(dest, op[0], op[1], cond);
1074       if (nir_src_bit_size(instr->src[0].src) > 32) {
1075          bld.MOV(result, subscript(dest, BRW_REGISTER_TYPE_UD, 0));
1076       }
1077       break;
1078    }
1079 
1080    case nir_op_inot:
1081       if (devinfo->gen >= 8) {
1082          op[0] = resolve_source_modifiers(op[0]);
1083       }
1084       bld.NOT(result, op[0]);
1085       break;
1086    case nir_op_ixor:
1087       if (devinfo->gen >= 8) {
1088          op[0] = resolve_source_modifiers(op[0]);
1089          op[1] = resolve_source_modifiers(op[1]);
1090       }
1091       bld.XOR(result, op[0], op[1]);
1092       break;
1093    case nir_op_ior:
1094       if (devinfo->gen >= 8) {
1095          op[0] = resolve_source_modifiers(op[0]);
1096          op[1] = resolve_source_modifiers(op[1]);
1097       }
1098       bld.OR(result, op[0], op[1]);
1099       break;
1100    case nir_op_iand:
1101       if (devinfo->gen >= 8) {
1102          op[0] = resolve_source_modifiers(op[0]);
1103          op[1] = resolve_source_modifiers(op[1]);
1104       }
1105       bld.AND(result, op[0], op[1]);
1106       break;
1107 
1108    case nir_op_fdot2:
1109    case nir_op_fdot3:
1110    case nir_op_fdot4:
1111    case nir_op_ball_fequal2:
1112    case nir_op_ball_iequal2:
1113    case nir_op_ball_fequal3:
1114    case nir_op_ball_iequal3:
1115    case nir_op_ball_fequal4:
1116    case nir_op_ball_iequal4:
1117    case nir_op_bany_fnequal2:
1118    case nir_op_bany_inequal2:
1119    case nir_op_bany_fnequal3:
1120    case nir_op_bany_inequal3:
1121    case nir_op_bany_fnequal4:
1122    case nir_op_bany_inequal4:
1123       unreachable("Lowered by nir_lower_alu_reductions");
1124 
1125    case nir_op_fnoise1_1:
1126    case nir_op_fnoise1_2:
1127    case nir_op_fnoise1_3:
1128    case nir_op_fnoise1_4:
1129    case nir_op_fnoise2_1:
1130    case nir_op_fnoise2_2:
1131    case nir_op_fnoise2_3:
1132    case nir_op_fnoise2_4:
1133    case nir_op_fnoise3_1:
1134    case nir_op_fnoise3_2:
1135    case nir_op_fnoise3_3:
1136    case nir_op_fnoise3_4:
1137    case nir_op_fnoise4_1:
1138    case nir_op_fnoise4_2:
1139    case nir_op_fnoise4_3:
1140    case nir_op_fnoise4_4:
1141       unreachable("not reached: should be handled by lower_noise");
1142 
1143    case nir_op_ldexp:
1144       unreachable("not reached: should be handled by ldexp_to_arith()");
1145 
1146    case nir_op_fsqrt:
1147       inst = bld.emit(SHADER_OPCODE_SQRT, result, op[0]);
1148       inst->saturate = instr->dest.saturate;
1149       break;
1150 
1151    case nir_op_frsq:
1152       inst = bld.emit(SHADER_OPCODE_RSQ, result, op[0]);
1153       inst->saturate = instr->dest.saturate;
1154       break;
1155 
1156    case nir_op_b2i:
1157    case nir_op_b2f:
1158       bld.MOV(result, negate(op[0]));
1159       break;
1160 
1161    case nir_op_i2b:
1162    case nir_op_f2b:
1163       if (nir_src_bit_size(instr->src[0].src) == 64) {
1164          /* two-argument instructions can't take 64-bit immediates */
1165          fs_reg zero;
1166          fs_reg tmp;
1167 
1168          if (instr->op == nir_op_f2b) {
1169             zero = vgrf(glsl_type::double_type);
1170             tmp = vgrf(glsl_type::double_type);
1171             bld.MOV(zero, setup_imm_df(bld, 0.0));
1172          } else {
1173             zero = vgrf(glsl_type::int64_t_type);
1174             tmp = vgrf(glsl_type::int64_t_type);
1175             bld.MOV(zero, brw_imm_q(0));
1176          }
1177 
1178          /* A SIMD16 execution needs to be split in two instructions, so use
1179           * a vgrf instead of the flag register as dst so instruction splitting
1180           * works
1181           */
1182          bld.CMP(tmp, op[0], zero, BRW_CONDITIONAL_NZ);
1183          bld.MOV(result, subscript(tmp, BRW_REGISTER_TYPE_UD, 0));
1184       } else {
1185          if (instr->op == nir_op_f2b) {
1186             bld.CMP(result, op[0], brw_imm_f(0.0f), BRW_CONDITIONAL_NZ);
1187          } else {
1188             bld.CMP(result, op[0], brw_imm_d(0), BRW_CONDITIONAL_NZ);
1189          }
1190       }
1191       break;
1192 
1193    case nir_op_ftrunc:
1194       inst = bld.RNDZ(result, op[0]);
1195       inst->saturate = instr->dest.saturate;
1196       break;
1197 
1198    case nir_op_fceil: {
1199       op[0].negate = !op[0].negate;
1200       fs_reg temp = vgrf(glsl_type::float_type);
1201       bld.RNDD(temp, op[0]);
1202       temp.negate = true;
1203       inst = bld.MOV(result, temp);
1204       inst->saturate = instr->dest.saturate;
1205       break;
1206    }
1207    case nir_op_ffloor:
1208       inst = bld.RNDD(result, op[0]);
1209       inst->saturate = instr->dest.saturate;
1210       break;
1211    case nir_op_ffract:
1212       inst = bld.FRC(result, op[0]);
1213       inst->saturate = instr->dest.saturate;
1214       break;
1215    case nir_op_fround_even:
1216       inst = bld.RNDE(result, op[0]);
1217       inst->saturate = instr->dest.saturate;
1218       break;
1219 
1220    case nir_op_fquantize2f16: {
1221       fs_reg tmp16 = bld.vgrf(BRW_REGISTER_TYPE_D);
1222       fs_reg tmp32 = bld.vgrf(BRW_REGISTER_TYPE_F);
1223       fs_reg zero = bld.vgrf(BRW_REGISTER_TYPE_F);
1224 
1225       /* The destination stride must be at least as big as the source stride. */
1226       tmp16.type = BRW_REGISTER_TYPE_W;
1227       tmp16.stride = 2;
1228 
1229       /* Check for denormal */
1230       fs_reg abs_src0 = op[0];
1231       abs_src0.abs = true;
1232       bld.CMP(bld.null_reg_f(), abs_src0, brw_imm_f(ldexpf(1.0, -14)),
1233               BRW_CONDITIONAL_L);
1234       /* Get the appropriately signed zero */
1235       bld.AND(retype(zero, BRW_REGISTER_TYPE_UD),
1236               retype(op[0], BRW_REGISTER_TYPE_UD),
1237               brw_imm_ud(0x80000000));
1238       /* Do the actual F32 -> F16 -> F32 conversion */
1239       bld.emit(BRW_OPCODE_F32TO16, tmp16, op[0]);
1240       bld.emit(BRW_OPCODE_F16TO32, tmp32, tmp16);
1241       /* Select that or zero based on normal status */
1242       inst = bld.SEL(result, zero, tmp32);
1243       inst->predicate = BRW_PREDICATE_NORMAL;
1244       inst->saturate = instr->dest.saturate;
1245       break;
1246    }
1247 
1248    case nir_op_imin:
1249    case nir_op_umin:
1250    case nir_op_fmin:
1251       inst = bld.emit_minmax(result, op[0], op[1], BRW_CONDITIONAL_L);
1252       inst->saturate = instr->dest.saturate;
1253       break;
1254 
1255    case nir_op_imax:
1256    case nir_op_umax:
1257    case nir_op_fmax:
1258       inst = bld.emit_minmax(result, op[0], op[1], BRW_CONDITIONAL_GE);
1259       inst->saturate = instr->dest.saturate;
1260       break;
1261 
1262    case nir_op_pack_snorm_2x16:
1263    case nir_op_pack_snorm_4x8:
1264    case nir_op_pack_unorm_2x16:
1265    case nir_op_pack_unorm_4x8:
1266    case nir_op_unpack_snorm_2x16:
1267    case nir_op_unpack_snorm_4x8:
1268    case nir_op_unpack_unorm_2x16:
1269    case nir_op_unpack_unorm_4x8:
1270    case nir_op_unpack_half_2x16:
1271    case nir_op_pack_half_2x16:
1272       unreachable("not reached: should be handled by lower_packing_builtins");
1273 
1274    case nir_op_unpack_half_2x16_split_x:
1275       inst = bld.emit(FS_OPCODE_UNPACK_HALF_2x16_SPLIT_X, result, op[0]);
1276       inst->saturate = instr->dest.saturate;
1277       break;
1278    case nir_op_unpack_half_2x16_split_y:
1279       inst = bld.emit(FS_OPCODE_UNPACK_HALF_2x16_SPLIT_Y, result, op[0]);
1280       inst->saturate = instr->dest.saturate;
1281       break;
1282 
1283    case nir_op_pack_64_2x32_split:
1284       bld.emit(FS_OPCODE_PACK, result, op[0], op[1]);
1285       break;
1286 
1287    case nir_op_unpack_64_2x32_split_x:
1288    case nir_op_unpack_64_2x32_split_y: {
1289       if (instr->op == nir_op_unpack_64_2x32_split_x)
1290          bld.MOV(result, subscript(op[0], BRW_REGISTER_TYPE_UD, 0));
1291       else
1292          bld.MOV(result, subscript(op[0], BRW_REGISTER_TYPE_UD, 1));
1293       break;
1294    }
1295 
1296    case nir_op_fpow:
1297       inst = bld.emit(SHADER_OPCODE_POW, result, op[0], op[1]);
1298       inst->saturate = instr->dest.saturate;
1299       break;
1300 
1301    case nir_op_bitfield_reverse:
1302       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1303       bld.BFREV(result, op[0]);
1304       break;
1305 
1306    case nir_op_bit_count:
1307       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1308       bld.CBIT(result, op[0]);
1309       break;
1310 
1311    case nir_op_ufind_msb: {
1312       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1313       emit_find_msb_using_lzd(bld, result, op[0], false);
1314       break;
1315    }
1316 
1317    case nir_op_ifind_msb: {
1318       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1319 
1320       if (devinfo->gen < 7) {
1321          emit_find_msb_using_lzd(bld, result, op[0], true);
1322       } else {
1323          bld.FBH(retype(result, BRW_REGISTER_TYPE_UD), op[0]);
1324 
1325          /* FBH counts from the MSB side, while GLSL's findMSB() wants the
1326           * count from the LSB side. If FBH didn't return an error
1327           * (0xFFFFFFFF), then subtract the result from 31 to convert the MSB
1328           * count into an LSB count.
1329           */
1330          bld.CMP(bld.null_reg_d(), result, brw_imm_d(-1), BRW_CONDITIONAL_NZ);
1331 
1332          inst = bld.ADD(result, result, brw_imm_d(31));
1333          inst->predicate = BRW_PREDICATE_NORMAL;
1334          inst->src[0].negate = true;
1335       }
1336       break;
1337    }
1338 
1339    case nir_op_find_lsb:
1340       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1341 
1342       if (devinfo->gen < 7) {
1343          fs_reg temp = vgrf(glsl_type::int_type);
1344 
1345          /* (x & -x) generates a value that consists of only the LSB of x.
1346           * For all powers of 2, findMSB(y) == findLSB(y).
1347           */
1348          fs_reg src = retype(op[0], BRW_REGISTER_TYPE_D);
1349          fs_reg negated_src = src;
1350 
1351          /* One must be negated, and the other must be non-negated.  It
1352           * doesn't matter which is which.
1353           */
1354          negated_src.negate = true;
1355          src.negate = false;
1356 
1357          bld.AND(temp, src, negated_src);
1358          emit_find_msb_using_lzd(bld, result, temp, false);
1359       } else {
1360          bld.FBL(result, op[0]);
1361       }
1362       break;
1363 
1364    case nir_op_ubitfield_extract:
1365    case nir_op_ibitfield_extract:
1366       unreachable("should have been lowered");
1367    case nir_op_ubfe:
1368    case nir_op_ibfe:
1369       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1370       bld.BFE(result, op[2], op[1], op[0]);
1371       break;
1372    case nir_op_bfm:
1373       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1374       bld.BFI1(result, op[0], op[1]);
1375       break;
1376    case nir_op_bfi:
1377       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1378       bld.BFI2(result, op[0], op[1], op[2]);
1379       break;
1380 
1381    case nir_op_bitfield_insert:
1382       unreachable("not reached: should have been lowered");
1383 
1384    case nir_op_ishl:
1385    case nir_op_ishr:
1386    case nir_op_ushr: {
1387       fs_reg shift_count = op[1];
1388 
1389       if (devinfo->is_cherryview || gen_device_info_is_9lp(devinfo)) {
1390          if (op[1].file == VGRF &&
1391              (result.type == BRW_REGISTER_TYPE_Q ||
1392               result.type == BRW_REGISTER_TYPE_UQ)) {
1393             shift_count = fs_reg(VGRF, alloc.allocate(dispatch_width / 4),
1394                                  BRW_REGISTER_TYPE_UD);
1395             shift_count.stride = 2;
1396             bld.MOV(shift_count, op[1]);
1397          }
1398       }
1399 
1400       switch (instr->op) {
1401       case nir_op_ishl:
1402          bld.SHL(result, op[0], shift_count);
1403          break;
1404       case nir_op_ishr:
1405          bld.ASR(result, op[0], shift_count);
1406          break;
1407       case nir_op_ushr:
1408          bld.SHR(result, op[0], shift_count);
1409          break;
1410       default:
1411          unreachable("not reached");
1412       }
1413       break;
1414    }
1415 
1416    case nir_op_pack_half_2x16_split:
1417       bld.emit(FS_OPCODE_PACK_HALF_2x16_SPLIT, result, op[0], op[1]);
1418       break;
1419 
1420    case nir_op_ffma:
1421       inst = bld.MAD(result, op[2], op[1], op[0]);
1422       inst->saturate = instr->dest.saturate;
1423       break;
1424 
1425    case nir_op_flrp:
1426       inst = bld.LRP(result, op[0], op[1], op[2]);
1427       inst->saturate = instr->dest.saturate;
1428       break;
1429 
1430    case nir_op_bcsel:
1431       if (optimize_frontfacing_ternary(instr, result))
1432          return;
1433 
1434       bld.CMP(bld.null_reg_d(), op[0], brw_imm_d(0), BRW_CONDITIONAL_NZ);
1435       inst = bld.SEL(result, op[1], op[2]);
1436       inst->predicate = BRW_PREDICATE_NORMAL;
1437       break;
1438 
1439    case nir_op_extract_u8:
1440    case nir_op_extract_i8: {
1441       nir_const_value *byte = nir_src_as_const_value(instr->src[1].src);
1442       assert(byte != NULL);
1443 
1444       /* The PRMs say:
1445        *
1446        *    BDW+
1447        *    There is no direct conversion from B/UB to Q/UQ or Q/UQ to B/UB.
1448        *    Use two instructions and a word or DWord intermediate integer type.
1449        */
1450       if (nir_dest_bit_size(instr->dest.dest) == 64) {
1451          const brw_reg_type type = brw_int_type(2, instr->op == nir_op_extract_i8);
1452 
1453          if (instr->op == nir_op_extract_i8) {
1454             /* If we need to sign extend, extract to a word first */
1455             fs_reg w_temp = bld.vgrf(BRW_REGISTER_TYPE_W);
1456             bld.MOV(w_temp, subscript(op[0], type, byte->u32[0]));
1457             bld.MOV(result, w_temp);
1458          } else {
1459             /* Otherwise use an AND with 0xff and a word type */
1460             bld.AND(result, subscript(op[0], type, byte->u32[0] / 2), brw_imm_uw(0xff));
1461          }
1462       } else {
1463          const brw_reg_type type = brw_int_type(1, instr->op == nir_op_extract_i8);
1464          bld.MOV(result, subscript(op[0], type, byte->u32[0]));
1465       }
1466       break;
1467    }
1468 
1469    case nir_op_extract_u16:
1470    case nir_op_extract_i16: {
1471       const brw_reg_type type = brw_int_type(2, instr->op == nir_op_extract_i16);
1472       nir_const_value *word = nir_src_as_const_value(instr->src[1].src);
1473       assert(word != NULL);
1474       bld.MOV(result, subscript(op[0], type, word->u32[0]));
1475       break;
1476    }
1477 
1478    default:
1479       unreachable("unhandled instruction");
1480    }
1481 
1482    /* If we need to do a boolean resolve, replace the result with -(x & 1)
1483     * to sign extend the low bit to 0/~0
1484     */
1485    if (devinfo->gen <= 5 &&
1486        (instr->instr.pass_flags & BRW_NIR_BOOLEAN_MASK) == BRW_NIR_BOOLEAN_NEEDS_RESOLVE) {
1487       fs_reg masked = vgrf(glsl_type::int_type);
1488       bld.AND(masked, result, brw_imm_d(1));
1489       masked.negate = true;
1490       bld.MOV(retype(result, BRW_REGISTER_TYPE_D), masked);
1491    }
1492 }
1493 
1494 void
nir_emit_load_const(const fs_builder & bld,nir_load_const_instr * instr)1495 fs_visitor::nir_emit_load_const(const fs_builder &bld,
1496                                 nir_load_const_instr *instr)
1497 {
1498    const brw_reg_type reg_type =
1499       brw_reg_type_from_bit_size(instr->def.bit_size, BRW_REGISTER_TYPE_D);
1500    fs_reg reg = bld.vgrf(reg_type, instr->def.num_components);
1501 
1502    switch (instr->def.bit_size) {
1503    case 32:
1504       for (unsigned i = 0; i < instr->def.num_components; i++)
1505          bld.MOV(offset(reg, bld, i), brw_imm_d(instr->value.i32[i]));
1506       break;
1507 
1508    case 64:
1509       assert(devinfo->gen >= 7);
1510       if (devinfo->gen == 7) {
1511          /* We don't get 64-bit integer types until gen8 */
1512          for (unsigned i = 0; i < instr->def.num_components; i++) {
1513             bld.MOV(retype(offset(reg, bld, i), BRW_REGISTER_TYPE_DF),
1514                     setup_imm_df(bld, instr->value.f64[i]));
1515          }
1516       } else {
1517          for (unsigned i = 0; i < instr->def.num_components; i++)
1518             bld.MOV(offset(reg, bld, i), brw_imm_q(instr->value.i64[i]));
1519       }
1520       break;
1521 
1522    default:
1523       unreachable("Invalid bit size");
1524    }
1525 
1526    nir_ssa_values[instr->def.index] = reg;
1527 }
1528 
1529 fs_reg
get_nir_src(const nir_src & src)1530 fs_visitor::get_nir_src(const nir_src &src)
1531 {
1532    fs_reg reg;
1533    if (src.is_ssa) {
1534       if (src.ssa->parent_instr->type == nir_instr_type_ssa_undef) {
1535          const brw_reg_type reg_type =
1536             brw_reg_type_from_bit_size(src.ssa->bit_size, BRW_REGISTER_TYPE_D);
1537          reg = bld.vgrf(reg_type, src.ssa->num_components);
1538       } else {
1539          reg = nir_ssa_values[src.ssa->index];
1540       }
1541    } else {
1542       /* We don't handle indirects on locals */
1543       assert(src.reg.indirect == NULL);
1544       reg = offset(nir_locals[src.reg.reg->index], bld,
1545                    src.reg.base_offset * src.reg.reg->num_components);
1546    }
1547 
1548    if (nir_src_bit_size(src) == 64 && devinfo->gen == 7) {
1549       /* The only 64-bit type available on gen7 is DF, so use that. */
1550       reg.type = BRW_REGISTER_TYPE_DF;
1551    } else {
1552       /* To avoid floating-point denorm flushing problems, set the type by
1553        * default to an integer type - instructions that need floating point
1554        * semantics will set this to F if they need to
1555        */
1556       reg.type = brw_reg_type_from_bit_size(nir_src_bit_size(src),
1557                                             BRW_REGISTER_TYPE_D);
1558    }
1559 
1560    return reg;
1561 }
1562 
1563 /**
1564  * Return an IMM for constants; otherwise call get_nir_src() as normal.
1565  *
1566  * This function should not be called on any value which may be 64 bits.
1567  * We could theoretically support 64-bit on gen8+ but we choose not to
1568  * because it wouldn't work in general (no gen7 support) and there are
1569  * enough restrictions in 64-bit immediates that you can't take the return
1570  * value and treat it the same as the result of get_nir_src().
1571  */
1572 fs_reg
get_nir_src_imm(const nir_src & src)1573 fs_visitor::get_nir_src_imm(const nir_src &src)
1574 {
1575    nir_const_value *val = nir_src_as_const_value(src);
1576    assert(nir_src_bit_size(src) == 32);
1577    return val ? fs_reg(brw_imm_d(val->i32[0])) : get_nir_src(src);
1578 }
1579 
1580 fs_reg
get_nir_dest(const nir_dest & dest)1581 fs_visitor::get_nir_dest(const nir_dest &dest)
1582 {
1583    if (dest.is_ssa) {
1584       const brw_reg_type reg_type =
1585          brw_reg_type_from_bit_size(dest.ssa.bit_size, BRW_REGISTER_TYPE_F);
1586       nir_ssa_values[dest.ssa.index] =
1587          bld.vgrf(reg_type, dest.ssa.num_components);
1588       return nir_ssa_values[dest.ssa.index];
1589    } else {
1590       /* We don't handle indirects on locals */
1591       assert(dest.reg.indirect == NULL);
1592       return offset(nir_locals[dest.reg.reg->index], bld,
1593                     dest.reg.base_offset * dest.reg.reg->num_components);
1594    }
1595 }
1596 
1597 fs_reg
get_nir_image_deref(const nir_deref_var * deref)1598 fs_visitor::get_nir_image_deref(const nir_deref_var *deref)
1599 {
1600    fs_reg image(UNIFORM, deref->var->data.driver_location / 4,
1601                 BRW_REGISTER_TYPE_UD);
1602    fs_reg indirect;
1603    unsigned indirect_max = 0;
1604 
1605    for (const nir_deref *tail = &deref->deref; tail->child;
1606         tail = tail->child) {
1607       const nir_deref_array *deref_array = nir_deref_as_array(tail->child);
1608       assert(tail->child->deref_type == nir_deref_type_array);
1609       const unsigned size = glsl_get_length(tail->type);
1610       const unsigned element_size = type_size_scalar(deref_array->deref.type);
1611       const unsigned base = MIN2(deref_array->base_offset, size - 1);
1612       image = offset(image, bld, base * element_size);
1613 
1614       if (deref_array->deref_array_type == nir_deref_array_type_indirect) {
1615          fs_reg tmp = vgrf(glsl_type::uint_type);
1616 
1617          /* Accessing an invalid surface index with the dataport can result
1618           * in a hang.  According to the spec "if the index used to
1619           * select an individual element is negative or greater than or
1620           * equal to the size of the array, the results of the operation
1621           * are undefined but may not lead to termination" -- which is one
1622           * of the possible outcomes of the hang.  Clamp the index to
1623           * prevent access outside of the array bounds.
1624           */
1625          bld.emit_minmax(tmp, retype(get_nir_src(deref_array->indirect),
1626                                      BRW_REGISTER_TYPE_UD),
1627                          brw_imm_ud(size - base - 1), BRW_CONDITIONAL_L);
1628 
1629          indirect_max += element_size * (tail->type->length - 1);
1630 
1631          bld.MUL(tmp, tmp, brw_imm_ud(element_size * 4));
1632          if (indirect.file == BAD_FILE) {
1633             indirect = tmp;
1634          } else {
1635             bld.ADD(indirect, indirect, tmp);
1636          }
1637       }
1638    }
1639 
1640    if (indirect.file == BAD_FILE) {
1641       return image;
1642    } else {
1643       /* Emit a pile of MOVs to load the uniform into a temporary.  The
1644        * dead-code elimination pass will get rid of what we don't use.
1645        */
1646       fs_reg tmp = bld.vgrf(BRW_REGISTER_TYPE_UD, BRW_IMAGE_PARAM_SIZE);
1647       for (unsigned j = 0; j < BRW_IMAGE_PARAM_SIZE; j++) {
1648          bld.emit(SHADER_OPCODE_MOV_INDIRECT,
1649                   offset(tmp, bld, j), offset(image, bld, j),
1650                   indirect, brw_imm_ud((indirect_max + 1) * 4));
1651       }
1652       return tmp;
1653    }
1654 }
1655 
1656 void
emit_percomp(const fs_builder & bld,const fs_inst & inst,unsigned wr_mask)1657 fs_visitor::emit_percomp(const fs_builder &bld, const fs_inst &inst,
1658                          unsigned wr_mask)
1659 {
1660    for (unsigned i = 0; i < 4; i++) {
1661       if (!((wr_mask >> i) & 1))
1662          continue;
1663 
1664       fs_inst *new_inst = new(mem_ctx) fs_inst(inst);
1665       new_inst->dst = offset(new_inst->dst, bld, i);
1666       for (unsigned j = 0; j < new_inst->sources; j++)
1667          if (new_inst->src[j].file == VGRF)
1668             new_inst->src[j] = offset(new_inst->src[j], bld, i);
1669 
1670       bld.emit(new_inst);
1671    }
1672 }
1673 
1674 /**
1675  * Get the matching channel register datatype for an image intrinsic of the
1676  * specified GLSL image type.
1677  */
1678 static brw_reg_type
get_image_base_type(const glsl_type * type)1679 get_image_base_type(const glsl_type *type)
1680 {
1681    switch ((glsl_base_type)type->sampled_type) {
1682    case GLSL_TYPE_UINT:
1683       return BRW_REGISTER_TYPE_UD;
1684    case GLSL_TYPE_INT:
1685       return BRW_REGISTER_TYPE_D;
1686    case GLSL_TYPE_FLOAT:
1687       return BRW_REGISTER_TYPE_F;
1688    default:
1689       unreachable("Not reached.");
1690    }
1691 }
1692 
1693 /**
1694  * Get the appropriate atomic op for an image atomic intrinsic.
1695  */
1696 static unsigned
get_image_atomic_op(nir_intrinsic_op op,const glsl_type * type)1697 get_image_atomic_op(nir_intrinsic_op op, const glsl_type *type)
1698 {
1699    switch (op) {
1700    case nir_intrinsic_image_atomic_add:
1701       return BRW_AOP_ADD;
1702    case nir_intrinsic_image_atomic_min:
1703       return (get_image_base_type(type) == BRW_REGISTER_TYPE_D ?
1704               BRW_AOP_IMIN : BRW_AOP_UMIN);
1705    case nir_intrinsic_image_atomic_max:
1706       return (get_image_base_type(type) == BRW_REGISTER_TYPE_D ?
1707               BRW_AOP_IMAX : BRW_AOP_UMAX);
1708    case nir_intrinsic_image_atomic_and:
1709       return BRW_AOP_AND;
1710    case nir_intrinsic_image_atomic_or:
1711       return BRW_AOP_OR;
1712    case nir_intrinsic_image_atomic_xor:
1713       return BRW_AOP_XOR;
1714    case nir_intrinsic_image_atomic_exchange:
1715       return BRW_AOP_MOV;
1716    case nir_intrinsic_image_atomic_comp_swap:
1717       return BRW_AOP_CMPWR;
1718    default:
1719       unreachable("Not reachable.");
1720    }
1721 }
1722 
1723 static fs_inst *
emit_pixel_interpolater_send(const fs_builder & bld,enum opcode opcode,const fs_reg & dst,const fs_reg & src,const fs_reg & desc,glsl_interp_mode interpolation)1724 emit_pixel_interpolater_send(const fs_builder &bld,
1725                              enum opcode opcode,
1726                              const fs_reg &dst,
1727                              const fs_reg &src,
1728                              const fs_reg &desc,
1729                              glsl_interp_mode interpolation)
1730 {
1731    struct brw_wm_prog_data *wm_prog_data =
1732       brw_wm_prog_data(bld.shader->stage_prog_data);
1733    fs_inst *inst;
1734    fs_reg payload;
1735    int mlen;
1736 
1737    if (src.file == BAD_FILE) {
1738       /* Dummy payload */
1739       payload = bld.vgrf(BRW_REGISTER_TYPE_F, 1);
1740       mlen = 1;
1741    } else {
1742       payload = src;
1743       mlen = 2 * bld.dispatch_width() / 8;
1744    }
1745 
1746    inst = bld.emit(opcode, dst, payload, desc);
1747    inst->mlen = mlen;
1748    /* 2 floats per slot returned */
1749    inst->size_written = 2 * dst.component_size(inst->exec_size);
1750    inst->pi_noperspective = interpolation == INTERP_MODE_NOPERSPECTIVE;
1751 
1752    wm_prog_data->pulls_bary = true;
1753 
1754    return inst;
1755 }
1756 
1757 /**
1758  * Computes 1 << x, given a D/UD register containing some value x.
1759  */
1760 static fs_reg
intexp2(const fs_builder & bld,const fs_reg & x)1761 intexp2(const fs_builder &bld, const fs_reg &x)
1762 {
1763    assert(x.type == BRW_REGISTER_TYPE_UD || x.type == BRW_REGISTER_TYPE_D);
1764 
1765    fs_reg result = bld.vgrf(x.type, 1);
1766    fs_reg one = bld.vgrf(x.type, 1);
1767 
1768    bld.MOV(one, retype(brw_imm_d(1), one.type));
1769    bld.SHL(result, one, x);
1770    return result;
1771 }
1772 
1773 void
emit_gs_end_primitive(const nir_src & vertex_count_nir_src)1774 fs_visitor::emit_gs_end_primitive(const nir_src &vertex_count_nir_src)
1775 {
1776    assert(stage == MESA_SHADER_GEOMETRY);
1777 
1778    struct brw_gs_prog_data *gs_prog_data = brw_gs_prog_data(prog_data);
1779 
1780    if (gs_compile->control_data_header_size_bits == 0)
1781       return;
1782 
1783    /* We can only do EndPrimitive() functionality when the control data
1784     * consists of cut bits.  Fortunately, the only time it isn't is when the
1785     * output type is points, in which case EndPrimitive() is a no-op.
1786     */
1787    if (gs_prog_data->control_data_format !=
1788        GEN7_GS_CONTROL_DATA_FORMAT_GSCTL_CUT) {
1789       return;
1790    }
1791 
1792    /* Cut bits use one bit per vertex. */
1793    assert(gs_compile->control_data_bits_per_vertex == 1);
1794 
1795    fs_reg vertex_count = get_nir_src(vertex_count_nir_src);
1796    vertex_count.type = BRW_REGISTER_TYPE_UD;
1797 
1798    /* Cut bit n should be set to 1 if EndPrimitive() was called after emitting
1799     * vertex n, 0 otherwise.  So all we need to do here is mark bit
1800     * (vertex_count - 1) % 32 in the cut_bits register to indicate that
1801     * EndPrimitive() was called after emitting vertex (vertex_count - 1);
1802     * vec4_gs_visitor::emit_control_data_bits() will take care of the rest.
1803     *
1804     * Note that if EndPrimitive() is called before emitting any vertices, this
1805     * will cause us to set bit 31 of the control_data_bits register to 1.
1806     * That's fine because:
1807     *
1808     * - If max_vertices < 32, then vertex number 31 (zero-based) will never be
1809     *   output, so the hardware will ignore cut bit 31.
1810     *
1811     * - If max_vertices == 32, then vertex number 31 is guaranteed to be the
1812     *   last vertex, so setting cut bit 31 has no effect (since the primitive
1813     *   is automatically ended when the GS terminates).
1814     *
1815     * - If max_vertices > 32, then the ir_emit_vertex visitor will reset the
1816     *   control_data_bits register to 0 when the first vertex is emitted.
1817     */
1818 
1819    const fs_builder abld = bld.annotate("end primitive");
1820 
1821    /* control_data_bits |= 1 << ((vertex_count - 1) % 32) */
1822    fs_reg prev_count = bld.vgrf(BRW_REGISTER_TYPE_UD, 1);
1823    abld.ADD(prev_count, vertex_count, brw_imm_ud(0xffffffffu));
1824    fs_reg mask = intexp2(abld, prev_count);
1825    /* Note: we're relying on the fact that the GEN SHL instruction only pays
1826     * attention to the lower 5 bits of its second source argument, so on this
1827     * architecture, 1 << (vertex_count - 1) is equivalent to 1 <<
1828     * ((vertex_count - 1) % 32).
1829     */
1830    abld.OR(this->control_data_bits, this->control_data_bits, mask);
1831 }
1832 
1833 void
emit_gs_control_data_bits(const fs_reg & vertex_count)1834 fs_visitor::emit_gs_control_data_bits(const fs_reg &vertex_count)
1835 {
1836    assert(stage == MESA_SHADER_GEOMETRY);
1837    assert(gs_compile->control_data_bits_per_vertex != 0);
1838 
1839    struct brw_gs_prog_data *gs_prog_data = brw_gs_prog_data(prog_data);
1840 
1841    const fs_builder abld = bld.annotate("emit control data bits");
1842    const fs_builder fwa_bld = bld.exec_all();
1843 
1844    /* We use a single UD register to accumulate control data bits (32 bits
1845     * for each of the SIMD8 channels).  So we need to write a DWord (32 bits)
1846     * at a time.
1847     *
1848     * Unfortunately, the URB_WRITE_SIMD8 message uses 128-bit (OWord) offsets.
1849     * We have select a 128-bit group via the Global and Per-Slot Offsets, then
1850     * use the Channel Mask phase to enable/disable which DWord within that
1851     * group to write.  (Remember, different SIMD8 channels may have emitted
1852     * different numbers of vertices, so we may need per-slot offsets.)
1853     *
1854     * Channel masking presents an annoying problem: we may have to replicate
1855     * the data up to 4 times:
1856     *
1857     * Msg = Handles, Per-Slot Offsets, Channel Masks, Data, Data, Data, Data.
1858     *
1859     * To avoid penalizing shaders that emit a small number of vertices, we
1860     * can avoid these sometimes: if the size of the control data header is
1861     * <= 128 bits, then there is only 1 OWord.  All SIMD8 channels will land
1862     * land in the same 128-bit group, so we can skip per-slot offsets.
1863     *
1864     * Similarly, if the control data header is <= 32 bits, there is only one
1865     * DWord, so we can skip channel masks.
1866     */
1867    enum opcode opcode = SHADER_OPCODE_URB_WRITE_SIMD8;
1868 
1869    fs_reg channel_mask, per_slot_offset;
1870 
1871    if (gs_compile->control_data_header_size_bits > 32) {
1872       opcode = SHADER_OPCODE_URB_WRITE_SIMD8_MASKED;
1873       channel_mask = vgrf(glsl_type::uint_type);
1874    }
1875 
1876    if (gs_compile->control_data_header_size_bits > 128) {
1877       opcode = SHADER_OPCODE_URB_WRITE_SIMD8_MASKED_PER_SLOT;
1878       per_slot_offset = vgrf(glsl_type::uint_type);
1879    }
1880 
1881    /* Figure out which DWord we're trying to write to using the formula:
1882     *
1883     *    dword_index = (vertex_count - 1) * bits_per_vertex / 32
1884     *
1885     * Since bits_per_vertex is a power of two, and is known at compile
1886     * time, this can be optimized to:
1887     *
1888     *    dword_index = (vertex_count - 1) >> (6 - log2(bits_per_vertex))
1889     */
1890    if (opcode != SHADER_OPCODE_URB_WRITE_SIMD8) {
1891       fs_reg dword_index = bld.vgrf(BRW_REGISTER_TYPE_UD, 1);
1892       fs_reg prev_count = bld.vgrf(BRW_REGISTER_TYPE_UD, 1);
1893       abld.ADD(prev_count, vertex_count, brw_imm_ud(0xffffffffu));
1894       unsigned log2_bits_per_vertex =
1895          util_last_bit(gs_compile->control_data_bits_per_vertex);
1896       abld.SHR(dword_index, prev_count, brw_imm_ud(6u - log2_bits_per_vertex));
1897 
1898       if (per_slot_offset.file != BAD_FILE) {
1899          /* Set the per-slot offset to dword_index / 4, so that we'll write to
1900           * the appropriate OWord within the control data header.
1901           */
1902          abld.SHR(per_slot_offset, dword_index, brw_imm_ud(2u));
1903       }
1904 
1905       /* Set the channel masks to 1 << (dword_index % 4), so that we'll
1906        * write to the appropriate DWORD within the OWORD.
1907        */
1908       fs_reg channel = bld.vgrf(BRW_REGISTER_TYPE_UD, 1);
1909       fwa_bld.AND(channel, dword_index, brw_imm_ud(3u));
1910       channel_mask = intexp2(fwa_bld, channel);
1911       /* Then the channel masks need to be in bits 23:16. */
1912       fwa_bld.SHL(channel_mask, channel_mask, brw_imm_ud(16u));
1913    }
1914 
1915    /* Store the control data bits in the message payload and send it. */
1916    int mlen = 2;
1917    if (channel_mask.file != BAD_FILE)
1918       mlen += 4; /* channel masks, plus 3 extra copies of the data */
1919    if (per_slot_offset.file != BAD_FILE)
1920       mlen++;
1921 
1922    fs_reg payload = bld.vgrf(BRW_REGISTER_TYPE_UD, mlen);
1923    fs_reg *sources = ralloc_array(mem_ctx, fs_reg, mlen);
1924    int i = 0;
1925    sources[i++] = fs_reg(retype(brw_vec8_grf(1, 0), BRW_REGISTER_TYPE_UD));
1926    if (per_slot_offset.file != BAD_FILE)
1927       sources[i++] = per_slot_offset;
1928    if (channel_mask.file != BAD_FILE)
1929       sources[i++] = channel_mask;
1930    while (i < mlen) {
1931       sources[i++] = this->control_data_bits;
1932    }
1933 
1934    abld.LOAD_PAYLOAD(payload, sources, mlen, mlen);
1935    fs_inst *inst = abld.emit(opcode, reg_undef, payload);
1936    inst->mlen = mlen;
1937    /* We need to increment Global Offset by 256-bits to make room for
1938     * Broadwell's extra "Vertex Count" payload at the beginning of the
1939     * URB entry.  Since this is an OWord message, Global Offset is counted
1940     * in 128-bit units, so we must set it to 2.
1941     */
1942    if (gs_prog_data->static_vertex_count == -1)
1943       inst->offset = 2;
1944 }
1945 
1946 void
set_gs_stream_control_data_bits(const fs_reg & vertex_count,unsigned stream_id)1947 fs_visitor::set_gs_stream_control_data_bits(const fs_reg &vertex_count,
1948                                             unsigned stream_id)
1949 {
1950    /* control_data_bits |= stream_id << ((2 * (vertex_count - 1)) % 32) */
1951 
1952    /* Note: we are calling this *before* increasing vertex_count, so
1953     * this->vertex_count == vertex_count - 1 in the formula above.
1954     */
1955 
1956    /* Stream mode uses 2 bits per vertex */
1957    assert(gs_compile->control_data_bits_per_vertex == 2);
1958 
1959    /* Must be a valid stream */
1960    assert(stream_id < MAX_VERTEX_STREAMS);
1961 
1962    /* Control data bits are initialized to 0 so we don't have to set any
1963     * bits when sending vertices to stream 0.
1964     */
1965    if (stream_id == 0)
1966       return;
1967 
1968    const fs_builder abld = bld.annotate("set stream control data bits", NULL);
1969 
1970    /* reg::sid = stream_id */
1971    fs_reg sid = bld.vgrf(BRW_REGISTER_TYPE_UD, 1);
1972    abld.MOV(sid, brw_imm_ud(stream_id));
1973 
1974    /* reg:shift_count = 2 * (vertex_count - 1) */
1975    fs_reg shift_count = bld.vgrf(BRW_REGISTER_TYPE_UD, 1);
1976    abld.SHL(shift_count, vertex_count, brw_imm_ud(1u));
1977 
1978    /* Note: we're relying on the fact that the GEN SHL instruction only pays
1979     * attention to the lower 5 bits of its second source argument, so on this
1980     * architecture, stream_id << 2 * (vertex_count - 1) is equivalent to
1981     * stream_id << ((2 * (vertex_count - 1)) % 32).
1982     */
1983    fs_reg mask = bld.vgrf(BRW_REGISTER_TYPE_UD, 1);
1984    abld.SHL(mask, sid, shift_count);
1985    abld.OR(this->control_data_bits, this->control_data_bits, mask);
1986 }
1987 
1988 void
emit_gs_vertex(const nir_src & vertex_count_nir_src,unsigned stream_id)1989 fs_visitor::emit_gs_vertex(const nir_src &vertex_count_nir_src,
1990                            unsigned stream_id)
1991 {
1992    assert(stage == MESA_SHADER_GEOMETRY);
1993 
1994    struct brw_gs_prog_data *gs_prog_data = brw_gs_prog_data(prog_data);
1995 
1996    fs_reg vertex_count = get_nir_src(vertex_count_nir_src);
1997    vertex_count.type = BRW_REGISTER_TYPE_UD;
1998 
1999    /* Haswell and later hardware ignores the "Render Stream Select" bits
2000     * from the 3DSTATE_STREAMOUT packet when the SOL stage is disabled,
2001     * and instead sends all primitives down the pipeline for rasterization.
2002     * If the SOL stage is enabled, "Render Stream Select" is honored and
2003     * primitives bound to non-zero streams are discarded after stream output.
2004     *
2005     * Since the only purpose of primives sent to non-zero streams is to
2006     * be recorded by transform feedback, we can simply discard all geometry
2007     * bound to these streams when transform feedback is disabled.
2008     */
2009    if (stream_id > 0 && !nir->info.has_transform_feedback_varyings)
2010       return;
2011 
2012    /* If we're outputting 32 control data bits or less, then we can wait
2013     * until the shader is over to output them all.  Otherwise we need to
2014     * output them as we go.  Now is the time to do it, since we're about to
2015     * output the vertex_count'th vertex, so it's guaranteed that the
2016     * control data bits associated with the (vertex_count - 1)th vertex are
2017     * correct.
2018     */
2019    if (gs_compile->control_data_header_size_bits > 32) {
2020       const fs_builder abld =
2021          bld.annotate("emit vertex: emit control data bits");
2022 
2023       /* Only emit control data bits if we've finished accumulating a batch
2024        * of 32 bits.  This is the case when:
2025        *
2026        *     (vertex_count * bits_per_vertex) % 32 == 0
2027        *
2028        * (in other words, when the last 5 bits of vertex_count *
2029        * bits_per_vertex are 0).  Assuming bits_per_vertex == 2^n for some
2030        * integer n (which is always the case, since bits_per_vertex is
2031        * always 1 or 2), this is equivalent to requiring that the last 5-n
2032        * bits of vertex_count are 0:
2033        *
2034        *     vertex_count & (2^(5-n) - 1) == 0
2035        *
2036        * 2^(5-n) == 2^5 / 2^n == 32 / bits_per_vertex, so this is
2037        * equivalent to:
2038        *
2039        *     vertex_count & (32 / bits_per_vertex - 1) == 0
2040        *
2041        * TODO: If vertex_count is an immediate, we could do some of this math
2042        *       at compile time...
2043        */
2044       fs_inst *inst =
2045          abld.AND(bld.null_reg_d(), vertex_count,
2046                   brw_imm_ud(32u / gs_compile->control_data_bits_per_vertex - 1u));
2047       inst->conditional_mod = BRW_CONDITIONAL_Z;
2048 
2049       abld.IF(BRW_PREDICATE_NORMAL);
2050       /* If vertex_count is 0, then no control data bits have been
2051        * accumulated yet, so we can skip emitting them.
2052        */
2053       abld.CMP(bld.null_reg_d(), vertex_count, brw_imm_ud(0u),
2054                BRW_CONDITIONAL_NEQ);
2055       abld.IF(BRW_PREDICATE_NORMAL);
2056       emit_gs_control_data_bits(vertex_count);
2057       abld.emit(BRW_OPCODE_ENDIF);
2058 
2059       /* Reset control_data_bits to 0 so we can start accumulating a new
2060        * batch.
2061        *
2062        * Note: in the case where vertex_count == 0, this neutralizes the
2063        * effect of any call to EndPrimitive() that the shader may have
2064        * made before outputting its first vertex.
2065        */
2066       inst = abld.MOV(this->control_data_bits, brw_imm_ud(0u));
2067       inst->force_writemask_all = true;
2068       abld.emit(BRW_OPCODE_ENDIF);
2069    }
2070 
2071    emit_urb_writes(vertex_count);
2072 
2073    /* In stream mode we have to set control data bits for all vertices
2074     * unless we have disabled control data bits completely (which we do
2075     * do for GL_POINTS outputs that don't use streams).
2076     */
2077    if (gs_compile->control_data_header_size_bits > 0 &&
2078        gs_prog_data->control_data_format ==
2079           GEN7_GS_CONTROL_DATA_FORMAT_GSCTL_SID) {
2080       set_gs_stream_control_data_bits(vertex_count, stream_id);
2081    }
2082 }
2083 
2084 void
emit_gs_input_load(const fs_reg & dst,const nir_src & vertex_src,unsigned base_offset,const nir_src & offset_src,unsigned num_components,unsigned first_component)2085 fs_visitor::emit_gs_input_load(const fs_reg &dst,
2086                                const nir_src &vertex_src,
2087                                unsigned base_offset,
2088                                const nir_src &offset_src,
2089                                unsigned num_components,
2090                                unsigned first_component)
2091 {
2092    struct brw_gs_prog_data *gs_prog_data = brw_gs_prog_data(prog_data);
2093 
2094    nir_const_value *vertex_const = nir_src_as_const_value(vertex_src);
2095    nir_const_value *offset_const = nir_src_as_const_value(offset_src);
2096    const unsigned push_reg_count = gs_prog_data->base.urb_read_length * 8;
2097 
2098    /* TODO: figure out push input layout for invocations == 1 */
2099    /* TODO: make this work with 64-bit inputs */
2100    if (gs_prog_data->invocations == 1 &&
2101        type_sz(dst.type) <= 4 &&
2102        offset_const != NULL && vertex_const != NULL &&
2103        4 * (base_offset + offset_const->u32[0]) < push_reg_count) {
2104       int imm_offset = (base_offset + offset_const->u32[0]) * 4 +
2105                        vertex_const->u32[0] * push_reg_count;
2106       for (unsigned i = 0; i < num_components; i++) {
2107          bld.MOV(offset(dst, bld, i),
2108                  fs_reg(ATTR, imm_offset + i + first_component, dst.type));
2109       }
2110       return;
2111    }
2112 
2113    /* Resort to the pull model.  Ensure the VUE handles are provided. */
2114    assert(gs_prog_data->base.include_vue_handles);
2115 
2116    unsigned first_icp_handle = gs_prog_data->include_primitive_id ? 3 : 2;
2117    fs_reg icp_handle = bld.vgrf(BRW_REGISTER_TYPE_UD, 1);
2118 
2119    if (gs_prog_data->invocations == 1) {
2120       if (vertex_const) {
2121          /* The vertex index is constant; just select the proper URB handle. */
2122          icp_handle =
2123             retype(brw_vec8_grf(first_icp_handle + vertex_const->i32[0], 0),
2124                    BRW_REGISTER_TYPE_UD);
2125       } else {
2126          /* The vertex index is non-constant.  We need to use indirect
2127           * addressing to fetch the proper URB handle.
2128           *
2129           * First, we start with the sequence <7, 6, 5, 4, 3, 2, 1, 0>
2130           * indicating that channel <n> should read the handle from
2131           * DWord <n>.  We convert that to bytes by multiplying by 4.
2132           *
2133           * Next, we convert the vertex index to bytes by multiplying
2134           * by 32 (shifting by 5), and add the two together.  This is
2135           * the final indirect byte offset.
2136           */
2137          fs_reg sequence = bld.vgrf(BRW_REGISTER_TYPE_UW, 1);
2138          fs_reg channel_offsets = bld.vgrf(BRW_REGISTER_TYPE_UD, 1);
2139          fs_reg vertex_offset_bytes = bld.vgrf(BRW_REGISTER_TYPE_UD, 1);
2140          fs_reg icp_offset_bytes = bld.vgrf(BRW_REGISTER_TYPE_UD, 1);
2141 
2142          /* sequence = <7, 6, 5, 4, 3, 2, 1, 0> */
2143          bld.MOV(sequence, fs_reg(brw_imm_v(0x76543210)));
2144          /* channel_offsets = 4 * sequence = <28, 24, 20, 16, 12, 8, 4, 0> */
2145          bld.SHL(channel_offsets, sequence, brw_imm_ud(2u));
2146          /* Convert vertex_index to bytes (multiply by 32) */
2147          bld.SHL(vertex_offset_bytes,
2148                  retype(get_nir_src(vertex_src), BRW_REGISTER_TYPE_UD),
2149                  brw_imm_ud(5u));
2150          bld.ADD(icp_offset_bytes, vertex_offset_bytes, channel_offsets);
2151 
2152          /* Use first_icp_handle as the base offset.  There is one register
2153           * of URB handles per vertex, so inform the register allocator that
2154           * we might read up to nir->info.gs.vertices_in registers.
2155           */
2156          bld.emit(SHADER_OPCODE_MOV_INDIRECT, icp_handle,
2157                   retype(brw_vec8_grf(first_icp_handle, 0), icp_handle.type),
2158                   fs_reg(icp_offset_bytes),
2159                   brw_imm_ud(nir->info.gs.vertices_in * REG_SIZE));
2160       }
2161    } else {
2162       assert(gs_prog_data->invocations > 1);
2163 
2164       if (vertex_const) {
2165          assert(devinfo->gen >= 9 || vertex_const->i32[0] <= 5);
2166          bld.MOV(icp_handle,
2167                  retype(brw_vec1_grf(first_icp_handle +
2168                                      vertex_const->i32[0] / 8,
2169                                      vertex_const->i32[0] % 8),
2170                         BRW_REGISTER_TYPE_UD));
2171       } else {
2172          /* The vertex index is non-constant.  We need to use indirect
2173           * addressing to fetch the proper URB handle.
2174           *
2175           */
2176          fs_reg icp_offset_bytes = bld.vgrf(BRW_REGISTER_TYPE_UD, 1);
2177 
2178          /* Convert vertex_index to bytes (multiply by 4) */
2179          bld.SHL(icp_offset_bytes,
2180                  retype(get_nir_src(vertex_src), BRW_REGISTER_TYPE_UD),
2181                  brw_imm_ud(2u));
2182 
2183          /* Use first_icp_handle as the base offset.  There is one DWord
2184           * of URB handles per vertex, so inform the register allocator that
2185           * we might read up to ceil(nir->info.gs.vertices_in / 8) registers.
2186           */
2187          bld.emit(SHADER_OPCODE_MOV_INDIRECT, icp_handle,
2188                   retype(brw_vec8_grf(first_icp_handle, 0), icp_handle.type),
2189                   fs_reg(icp_offset_bytes),
2190                   brw_imm_ud(DIV_ROUND_UP(nir->info.gs.vertices_in, 8) *
2191                              REG_SIZE));
2192       }
2193    }
2194 
2195    fs_inst *inst;
2196 
2197    fs_reg tmp_dst = dst;
2198    fs_reg indirect_offset = get_nir_src(offset_src);
2199    unsigned num_iterations = 1;
2200    unsigned orig_num_components = num_components;
2201 
2202    if (type_sz(dst.type) == 8) {
2203       if (num_components > 2) {
2204          num_iterations = 2;
2205          num_components = 2;
2206       }
2207       fs_reg tmp = fs_reg(VGRF, alloc.allocate(4), dst.type);
2208       tmp_dst = tmp;
2209       first_component = first_component / 2;
2210    }
2211 
2212    for (unsigned iter = 0; iter < num_iterations; iter++) {
2213       if (offset_const) {
2214          /* Constant indexing - use global offset. */
2215          if (first_component != 0) {
2216             unsigned read_components = num_components + first_component;
2217             fs_reg tmp = bld.vgrf(dst.type, read_components);
2218             inst = bld.emit(SHADER_OPCODE_URB_READ_SIMD8, tmp, icp_handle);
2219             inst->size_written = read_components *
2220                                  tmp.component_size(inst->exec_size);
2221             for (unsigned i = 0; i < num_components; i++) {
2222                bld.MOV(offset(tmp_dst, bld, i),
2223                        offset(tmp, bld, i + first_component));
2224             }
2225          } else {
2226             inst = bld.emit(SHADER_OPCODE_URB_READ_SIMD8, tmp_dst,
2227                             icp_handle);
2228             inst->size_written = num_components *
2229                                  tmp_dst.component_size(inst->exec_size);
2230          }
2231          inst->offset = base_offset + offset_const->u32[0];
2232          inst->mlen = 1;
2233       } else {
2234          /* Indirect indexing - use per-slot offsets as well. */
2235          const fs_reg srcs[] = { icp_handle, indirect_offset };
2236          unsigned read_components = num_components + first_component;
2237          fs_reg tmp = bld.vgrf(dst.type, read_components);
2238          fs_reg payload = bld.vgrf(BRW_REGISTER_TYPE_UD, 2);
2239          bld.LOAD_PAYLOAD(payload, srcs, ARRAY_SIZE(srcs), 0);
2240          if (first_component != 0) {
2241             inst = bld.emit(SHADER_OPCODE_URB_READ_SIMD8_PER_SLOT, tmp,
2242                             payload);
2243             inst->size_written = read_components *
2244                                  tmp.component_size(inst->exec_size);
2245             for (unsigned i = 0; i < num_components; i++) {
2246                bld.MOV(offset(tmp_dst, bld, i),
2247                        offset(tmp, bld, i + first_component));
2248             }
2249          } else {
2250             inst = bld.emit(SHADER_OPCODE_URB_READ_SIMD8_PER_SLOT, tmp_dst,
2251                          payload);
2252             inst->size_written = num_components *
2253                                  tmp_dst.component_size(inst->exec_size);
2254          }
2255          inst->offset = base_offset;
2256          inst->mlen = 2;
2257       }
2258 
2259       if (type_sz(dst.type) == 8) {
2260          shuffle_32bit_load_result_to_64bit_data(
2261             bld, tmp_dst, retype(tmp_dst, BRW_REGISTER_TYPE_F), num_components);
2262 
2263          for (unsigned c = 0; c < num_components; c++)
2264             bld.MOV(offset(dst, bld, iter * 2 + c), offset(tmp_dst, bld, c));
2265       }
2266 
2267       if (num_iterations > 1) {
2268          num_components = orig_num_components - 2;
2269          if(offset_const) {
2270             base_offset++;
2271          } else {
2272             fs_reg new_indirect = bld.vgrf(BRW_REGISTER_TYPE_UD, 1);
2273             bld.ADD(new_indirect, indirect_offset, brw_imm_ud(1u));
2274             indirect_offset = new_indirect;
2275          }
2276       }
2277    }
2278 }
2279 
2280 fs_reg
get_indirect_offset(nir_intrinsic_instr * instr)2281 fs_visitor::get_indirect_offset(nir_intrinsic_instr *instr)
2282 {
2283    nir_src *offset_src = nir_get_io_offset_src(instr);
2284    nir_const_value *const_value = nir_src_as_const_value(*offset_src);
2285 
2286    if (const_value) {
2287       /* The only constant offset we should find is 0.  brw_nir.c's
2288        * add_const_offset_to_base() will fold other constant offsets
2289        * into instr->const_index[0].
2290        */
2291       assert(const_value->u32[0] == 0);
2292       return fs_reg();
2293    }
2294 
2295    return get_nir_src(*offset_src);
2296 }
2297 
2298 static void
do_untyped_vector_read(const fs_builder & bld,const fs_reg dest,const fs_reg surf_index,const fs_reg offset_reg,unsigned num_components)2299 do_untyped_vector_read(const fs_builder &bld,
2300                        const fs_reg dest,
2301                        const fs_reg surf_index,
2302                        const fs_reg offset_reg,
2303                        unsigned num_components)
2304 {
2305    if (type_sz(dest.type) <= 2) {
2306       assert(dest.stride == 1);
2307 
2308       if (num_components > 1) {
2309          /* Pairs of 16-bit components can be read with untyped read, for 16-bit
2310           * vec3 4th component is ignored.
2311           */
2312          fs_reg read_result =
2313             emit_untyped_read(bld, surf_index, offset_reg,
2314                               1 /* dims */, DIV_ROUND_UP(num_components, 2),
2315                               BRW_PREDICATE_NONE);
2316          shuffle_32bit_load_result_to_16bit_data(bld,
2317                retype(dest, BRW_REGISTER_TYPE_W),
2318                retype(read_result, BRW_REGISTER_TYPE_D),
2319                num_components);
2320       } else {
2321          assert(num_components == 1);
2322          /* scalar 16-bit are read using one byte_scattered_read message */
2323          fs_reg read_result =
2324             emit_byte_scattered_read(bld, surf_index, offset_reg,
2325                                      1 /* dims */, 1,
2326                                      type_sz(dest.type) * 8 /* bit_size */,
2327                                      BRW_PREDICATE_NONE);
2328          bld.MOV(dest, subscript(read_result, dest.type, 0));
2329       }
2330    } else if (type_sz(dest.type) == 4) {
2331       fs_reg read_result = emit_untyped_read(bld, surf_index, offset_reg,
2332                                              1 /* dims */,
2333                                              num_components,
2334                                              BRW_PREDICATE_NONE);
2335       read_result.type = dest.type;
2336       for (unsigned i = 0; i < num_components; i++)
2337          bld.MOV(offset(dest, bld, i), offset(read_result, bld, i));
2338    } else if (type_sz(dest.type) == 8) {
2339       /* Reading a dvec, so we need to:
2340        *
2341        * 1. Multiply num_components by 2, to account for the fact that we
2342        *    need to read 64-bit components.
2343        * 2. Shuffle the result of the load to form valid 64-bit elements
2344        * 3. Emit a second load (for components z/w) if needed.
2345        */
2346       fs_reg read_offset = bld.vgrf(BRW_REGISTER_TYPE_UD);
2347       bld.MOV(read_offset, offset_reg);
2348 
2349       int iters = num_components <= 2 ? 1 : 2;
2350 
2351       /* Load the dvec, the first iteration loads components x/y, the second
2352        * iteration, if needed, loads components z/w
2353        */
2354       for (int it = 0; it < iters; it++) {
2355          /* Compute number of components to read in this iteration */
2356          int iter_components = MIN2(2, num_components);
2357          num_components -= iter_components;
2358 
2359          /* Read. Since this message reads 32-bit components, we need to
2360           * read twice as many components.
2361           */
2362          fs_reg read_result = emit_untyped_read(bld, surf_index, read_offset,
2363                                                 1 /* dims */,
2364                                                 iter_components * 2,
2365                                                 BRW_PREDICATE_NONE);
2366 
2367          /* Shuffle the 32-bit load result into valid 64-bit data */
2368          const fs_reg packed_result = bld.vgrf(dest.type, iter_components);
2369          shuffle_32bit_load_result_to_64bit_data(
2370             bld, packed_result, read_result, iter_components);
2371 
2372          /* Move each component to its destination */
2373          read_result = retype(read_result, BRW_REGISTER_TYPE_DF);
2374          for (int c = 0; c < iter_components; c++) {
2375             bld.MOV(offset(dest, bld, it * 2 + c),
2376                     offset(packed_result, bld, c));
2377          }
2378 
2379          bld.ADD(read_offset, read_offset, brw_imm_ud(16));
2380       }
2381    } else {
2382       unreachable("Unsupported type");
2383    }
2384 }
2385 
2386 void
nir_emit_vs_intrinsic(const fs_builder & bld,nir_intrinsic_instr * instr)2387 fs_visitor::nir_emit_vs_intrinsic(const fs_builder &bld,
2388                                   nir_intrinsic_instr *instr)
2389 {
2390    assert(stage == MESA_SHADER_VERTEX);
2391 
2392    fs_reg dest;
2393    if (nir_intrinsic_infos[instr->intrinsic].has_dest)
2394       dest = get_nir_dest(instr->dest);
2395 
2396    switch (instr->intrinsic) {
2397    case nir_intrinsic_load_vertex_id:
2398       unreachable("should be lowered by lower_vertex_id()");
2399 
2400    case nir_intrinsic_load_vertex_id_zero_base:
2401    case nir_intrinsic_load_base_vertex:
2402    case nir_intrinsic_load_instance_id:
2403    case nir_intrinsic_load_base_instance:
2404    case nir_intrinsic_load_draw_id: {
2405       gl_system_value sv = nir_system_value_from_intrinsic(instr->intrinsic);
2406       fs_reg val = nir_system_values[sv];
2407       assert(val.file != BAD_FILE);
2408       dest.type = val.type;
2409       bld.MOV(dest, val);
2410       break;
2411    }
2412 
2413    case nir_intrinsic_load_input: {
2414       fs_reg src = fs_reg(ATTR, nir_intrinsic_base(instr) * 4, dest.type);
2415       unsigned first_component = nir_intrinsic_component(instr);
2416       unsigned num_components = instr->num_components;
2417       enum brw_reg_type type = dest.type;
2418 
2419       nir_const_value *const_offset = nir_src_as_const_value(instr->src[0]);
2420       assert(const_offset && "Indirect input loads not allowed");
2421       src = offset(src, bld, const_offset->u32[0]);
2422 
2423       for (unsigned j = 0; j < num_components; j++) {
2424          bld.MOV(offset(dest, bld, j), offset(src, bld, j + first_component));
2425       }
2426 
2427       if (type == BRW_REGISTER_TYPE_DF) {
2428          /* Once the double vector is read, set again its original register
2429           * type to continue with normal execution.
2430           */
2431          src = retype(src, type);
2432          dest = retype(dest, type);
2433       }
2434 
2435       if (type_sz(src.type) == 8) {
2436          shuffle_32bit_load_result_to_64bit_data(bld,
2437                                                  dest,
2438                                                  retype(dest, BRW_REGISTER_TYPE_F),
2439                                                  instr->num_components);
2440       }
2441       break;
2442    }
2443 
2444    default:
2445       nir_emit_intrinsic(bld, instr);
2446       break;
2447    }
2448 }
2449 
2450 void
nir_emit_tcs_intrinsic(const fs_builder & bld,nir_intrinsic_instr * instr)2451 fs_visitor::nir_emit_tcs_intrinsic(const fs_builder &bld,
2452                                    nir_intrinsic_instr *instr)
2453 {
2454    assert(stage == MESA_SHADER_TESS_CTRL);
2455    struct brw_tcs_prog_key *tcs_key = (struct brw_tcs_prog_key *) key;
2456    struct brw_tcs_prog_data *tcs_prog_data = brw_tcs_prog_data(prog_data);
2457 
2458    fs_reg dst;
2459    if (nir_intrinsic_infos[instr->intrinsic].has_dest)
2460       dst = get_nir_dest(instr->dest);
2461 
2462    switch (instr->intrinsic) {
2463    case nir_intrinsic_load_primitive_id:
2464       bld.MOV(dst, fs_reg(brw_vec1_grf(0, 1)));
2465       break;
2466    case nir_intrinsic_load_invocation_id:
2467       bld.MOV(retype(dst, invocation_id.type), invocation_id);
2468       break;
2469    case nir_intrinsic_load_patch_vertices_in:
2470       bld.MOV(retype(dst, BRW_REGISTER_TYPE_D),
2471               brw_imm_d(tcs_key->input_vertices));
2472       break;
2473 
2474    case nir_intrinsic_barrier: {
2475       if (tcs_prog_data->instances == 1)
2476          break;
2477 
2478       fs_reg m0 = bld.vgrf(BRW_REGISTER_TYPE_UD, 1);
2479       fs_reg m0_2 = component(m0, 2);
2480 
2481       const fs_builder chanbld = bld.exec_all().group(1, 0);
2482 
2483       /* Zero the message header */
2484       bld.exec_all().MOV(m0, brw_imm_ud(0u));
2485 
2486       /* Copy "Barrier ID" from r0.2, bits 16:13 */
2487       chanbld.AND(m0_2, retype(brw_vec1_grf(0, 2), BRW_REGISTER_TYPE_UD),
2488                   brw_imm_ud(INTEL_MASK(16, 13)));
2489 
2490       /* Shift it up to bits 27:24. */
2491       chanbld.SHL(m0_2, m0_2, brw_imm_ud(11));
2492 
2493       /* Set the Barrier Count and the enable bit */
2494       chanbld.OR(m0_2, m0_2,
2495                  brw_imm_ud(tcs_prog_data->instances << 9 | (1 << 15)));
2496 
2497       bld.emit(SHADER_OPCODE_BARRIER, bld.null_reg_ud(), m0);
2498       break;
2499    }
2500 
2501    case nir_intrinsic_load_input:
2502       unreachable("nir_lower_io should never give us these.");
2503       break;
2504 
2505    case nir_intrinsic_load_per_vertex_input: {
2506       fs_reg indirect_offset = get_indirect_offset(instr);
2507       unsigned imm_offset = instr->const_index[0];
2508 
2509       const nir_src &vertex_src = instr->src[0];
2510       nir_const_value *vertex_const = nir_src_as_const_value(vertex_src);
2511 
2512       fs_inst *inst;
2513 
2514       fs_reg icp_handle;
2515 
2516       if (vertex_const) {
2517          /* Emit a MOV to resolve <0,1,0> regioning. */
2518          icp_handle = bld.vgrf(BRW_REGISTER_TYPE_UD, 1);
2519          bld.MOV(icp_handle,
2520                  retype(brw_vec1_grf(1 + (vertex_const->i32[0] >> 3),
2521                                      vertex_const->i32[0] & 7),
2522                         BRW_REGISTER_TYPE_UD));
2523       } else if (tcs_prog_data->instances == 1 &&
2524                  vertex_src.is_ssa &&
2525                  vertex_src.ssa->parent_instr->type == nir_instr_type_intrinsic &&
2526                  nir_instr_as_intrinsic(vertex_src.ssa->parent_instr)->intrinsic == nir_intrinsic_load_invocation_id) {
2527          /* For the common case of only 1 instance, an array index of
2528           * gl_InvocationID means reading g1.  Skip all the indirect work.
2529           */
2530          icp_handle = retype(brw_vec8_grf(1, 0), BRW_REGISTER_TYPE_UD);
2531       } else {
2532          /* The vertex index is non-constant.  We need to use indirect
2533           * addressing to fetch the proper URB handle.
2534           */
2535          icp_handle = bld.vgrf(BRW_REGISTER_TYPE_UD, 1);
2536 
2537          /* Each ICP handle is a single DWord (4 bytes) */
2538          fs_reg vertex_offset_bytes = bld.vgrf(BRW_REGISTER_TYPE_UD, 1);
2539          bld.SHL(vertex_offset_bytes,
2540                  retype(get_nir_src(vertex_src), BRW_REGISTER_TYPE_UD),
2541                  brw_imm_ud(2u));
2542 
2543          /* Start at g1.  We might read up to 4 registers. */
2544          bld.emit(SHADER_OPCODE_MOV_INDIRECT, icp_handle,
2545                   retype(brw_vec8_grf(1, 0), icp_handle.type), vertex_offset_bytes,
2546                   brw_imm_ud(4 * REG_SIZE));
2547       }
2548 
2549       /* We can only read two double components with each URB read, so
2550        * we send two read messages in that case, each one loading up to
2551        * two double components.
2552        */
2553       unsigned num_iterations = 1;
2554       unsigned num_components = instr->num_components;
2555       unsigned first_component = nir_intrinsic_component(instr);
2556       fs_reg orig_dst = dst;
2557       if (type_sz(dst.type) == 8) {
2558          first_component = first_component / 2;
2559          if (instr->num_components > 2) {
2560             num_iterations = 2;
2561             num_components = 2;
2562          }
2563 
2564          fs_reg tmp = fs_reg(VGRF, alloc.allocate(4), dst.type);
2565          dst = tmp;
2566       }
2567 
2568       for (unsigned iter = 0; iter < num_iterations; iter++) {
2569          if (indirect_offset.file == BAD_FILE) {
2570             /* Constant indexing - use global offset. */
2571             if (first_component != 0) {
2572                unsigned read_components = num_components + first_component;
2573                fs_reg tmp = bld.vgrf(dst.type, read_components);
2574                inst = bld.emit(SHADER_OPCODE_URB_READ_SIMD8, tmp, icp_handle);
2575                for (unsigned i = 0; i < num_components; i++) {
2576                   bld.MOV(offset(dst, bld, i),
2577                           offset(tmp, bld, i + first_component));
2578                }
2579             } else {
2580                inst = bld.emit(SHADER_OPCODE_URB_READ_SIMD8, dst, icp_handle);
2581             }
2582             inst->offset = imm_offset;
2583             inst->mlen = 1;
2584          } else {
2585             /* Indirect indexing - use per-slot offsets as well. */
2586             const fs_reg srcs[] = { icp_handle, indirect_offset };
2587             fs_reg payload = bld.vgrf(BRW_REGISTER_TYPE_UD, 2);
2588             bld.LOAD_PAYLOAD(payload, srcs, ARRAY_SIZE(srcs), 0);
2589             if (first_component != 0) {
2590                unsigned read_components = num_components + first_component;
2591                fs_reg tmp = bld.vgrf(dst.type, read_components);
2592                inst = bld.emit(SHADER_OPCODE_URB_READ_SIMD8_PER_SLOT, tmp,
2593                                payload);
2594                for (unsigned i = 0; i < num_components; i++) {
2595                   bld.MOV(offset(dst, bld, i),
2596                           offset(tmp, bld, i + first_component));
2597                }
2598             } else {
2599                inst = bld.emit(SHADER_OPCODE_URB_READ_SIMD8_PER_SLOT, dst,
2600                                payload);
2601             }
2602             inst->offset = imm_offset;
2603             inst->mlen = 2;
2604          }
2605          inst->size_written = (num_components + first_component) *
2606                               inst->dst.component_size(inst->exec_size);
2607 
2608          /* If we are reading 64-bit data using 32-bit read messages we need
2609           * build proper 64-bit data elements by shuffling the low and high
2610           * 32-bit components around like we do for other things like UBOs
2611           * or SSBOs.
2612           */
2613          if (type_sz(dst.type) == 8) {
2614             shuffle_32bit_load_result_to_64bit_data(
2615                bld, dst, retype(dst, BRW_REGISTER_TYPE_F), num_components);
2616 
2617             for (unsigned c = 0; c < num_components; c++) {
2618                bld.MOV(offset(orig_dst, bld, iter * 2 + c),
2619                        offset(dst, bld, c));
2620             }
2621          }
2622 
2623          /* Copy the temporary to the destination to deal with writemasking.
2624           *
2625           * Also attempt to deal with gl_PointSize being in the .w component.
2626           */
2627          if (inst->offset == 0 && indirect_offset.file == BAD_FILE) {
2628             assert(type_sz(dst.type) < 8);
2629             inst->dst = bld.vgrf(dst.type, 4);
2630             inst->size_written = 4 * REG_SIZE;
2631             bld.MOV(dst, offset(inst->dst, bld, 3));
2632          }
2633 
2634          /* If we are loading double data and we need a second read message
2635           * adjust the write offset
2636           */
2637          if (num_iterations > 1) {
2638             num_components = instr->num_components - 2;
2639             imm_offset++;
2640          }
2641       }
2642       break;
2643    }
2644 
2645    case nir_intrinsic_load_output:
2646    case nir_intrinsic_load_per_vertex_output: {
2647       fs_reg indirect_offset = get_indirect_offset(instr);
2648       unsigned imm_offset = instr->const_index[0];
2649       unsigned first_component = nir_intrinsic_component(instr);
2650 
2651       fs_inst *inst;
2652       if (indirect_offset.file == BAD_FILE) {
2653          /* Replicate the patch handle to all enabled channels */
2654          fs_reg patch_handle = bld.vgrf(BRW_REGISTER_TYPE_UD, 1);
2655          bld.MOV(patch_handle,
2656                  retype(brw_vec1_grf(0, 0), BRW_REGISTER_TYPE_UD));
2657 
2658          {
2659             if (first_component != 0) {
2660                unsigned read_components =
2661                   instr->num_components + first_component;
2662                fs_reg tmp = bld.vgrf(dst.type, read_components);
2663                inst = bld.emit(SHADER_OPCODE_URB_READ_SIMD8, tmp,
2664                                patch_handle);
2665                inst->size_written = read_components * REG_SIZE;
2666                for (unsigned i = 0; i < instr->num_components; i++) {
2667                   bld.MOV(offset(dst, bld, i),
2668                           offset(tmp, bld, i + first_component));
2669                }
2670             } else {
2671                inst = bld.emit(SHADER_OPCODE_URB_READ_SIMD8, dst,
2672                                patch_handle);
2673                inst->size_written = instr->num_components * REG_SIZE;
2674             }
2675             inst->offset = imm_offset;
2676             inst->mlen = 1;
2677          }
2678       } else {
2679          /* Indirect indexing - use per-slot offsets as well. */
2680          const fs_reg srcs[] = {
2681             retype(brw_vec1_grf(0, 0), BRW_REGISTER_TYPE_UD),
2682             indirect_offset
2683          };
2684          fs_reg payload = bld.vgrf(BRW_REGISTER_TYPE_UD, 2);
2685          bld.LOAD_PAYLOAD(payload, srcs, ARRAY_SIZE(srcs), 0);
2686          if (first_component != 0) {
2687             unsigned read_components =
2688                instr->num_components + first_component;
2689             fs_reg tmp = bld.vgrf(dst.type, read_components);
2690             inst = bld.emit(SHADER_OPCODE_URB_READ_SIMD8_PER_SLOT, tmp,
2691                             payload);
2692             inst->size_written = read_components * REG_SIZE;
2693             for (unsigned i = 0; i < instr->num_components; i++) {
2694                bld.MOV(offset(dst, bld, i),
2695                        offset(tmp, bld, i + first_component));
2696             }
2697          } else {
2698             inst = bld.emit(SHADER_OPCODE_URB_READ_SIMD8_PER_SLOT, dst,
2699                             payload);
2700             inst->size_written = instr->num_components * REG_SIZE;
2701          }
2702          inst->offset = imm_offset;
2703          inst->mlen = 2;
2704       }
2705       break;
2706    }
2707 
2708    case nir_intrinsic_store_output:
2709    case nir_intrinsic_store_per_vertex_output: {
2710       fs_reg value = get_nir_src(instr->src[0]);
2711       bool is_64bit = (instr->src[0].is_ssa ?
2712          instr->src[0].ssa->bit_size : instr->src[0].reg.reg->bit_size) == 64;
2713       fs_reg indirect_offset = get_indirect_offset(instr);
2714       unsigned imm_offset = instr->const_index[0];
2715       unsigned mask = instr->const_index[1];
2716       unsigned header_regs = 0;
2717       fs_reg srcs[7];
2718       srcs[header_regs++] = retype(brw_vec1_grf(0, 0), BRW_REGISTER_TYPE_UD);
2719 
2720       if (indirect_offset.file != BAD_FILE) {
2721          srcs[header_regs++] = indirect_offset;
2722       }
2723 
2724       if (mask == 0)
2725          break;
2726 
2727       unsigned num_components = util_last_bit(mask);
2728       enum opcode opcode;
2729 
2730       /* We can only pack two 64-bit components in a single message, so send
2731        * 2 messages if we have more components
2732        */
2733       unsigned num_iterations = 1;
2734       unsigned iter_components = num_components;
2735       unsigned first_component = nir_intrinsic_component(instr);
2736       if (is_64bit) {
2737          first_component = first_component / 2;
2738          if (instr->num_components > 2) {
2739             num_iterations = 2;
2740             iter_components = 2;
2741          }
2742       }
2743 
2744       mask = mask << first_component;
2745 
2746       for (unsigned iter = 0; iter < num_iterations; iter++) {
2747          if (!is_64bit && mask != WRITEMASK_XYZW) {
2748             srcs[header_regs++] = brw_imm_ud(mask << 16);
2749             opcode = indirect_offset.file != BAD_FILE ?
2750                SHADER_OPCODE_URB_WRITE_SIMD8_MASKED_PER_SLOT :
2751                SHADER_OPCODE_URB_WRITE_SIMD8_MASKED;
2752          } else if (is_64bit && ((mask & WRITEMASK_XY) != WRITEMASK_XY)) {
2753             /* Expand the 64-bit mask to 32-bit channels. We only handle
2754              * two channels in each iteration, so we only care about X/Y.
2755              */
2756             unsigned mask32 = 0;
2757             if (mask & WRITEMASK_X)
2758                mask32 |= WRITEMASK_XY;
2759             if (mask & WRITEMASK_Y)
2760                mask32 |= WRITEMASK_ZW;
2761 
2762             /* If the mask does not include any of the channels X or Y there
2763              * is nothing to do in this iteration. Move on to the next couple
2764              * of 64-bit channels.
2765              */
2766             if (!mask32) {
2767                mask >>= 2;
2768                imm_offset++;
2769                continue;
2770             }
2771 
2772             srcs[header_regs++] = brw_imm_ud(mask32 << 16);
2773             opcode = indirect_offset.file != BAD_FILE ?
2774                SHADER_OPCODE_URB_WRITE_SIMD8_MASKED_PER_SLOT :
2775                SHADER_OPCODE_URB_WRITE_SIMD8_MASKED;
2776          } else {
2777             opcode = indirect_offset.file != BAD_FILE ?
2778                SHADER_OPCODE_URB_WRITE_SIMD8_PER_SLOT :
2779                SHADER_OPCODE_URB_WRITE_SIMD8;
2780          }
2781 
2782          for (unsigned i = 0; i < iter_components; i++) {
2783             if (!(mask & (1 << (i + first_component))))
2784                continue;
2785 
2786             if (!is_64bit) {
2787                srcs[header_regs + i + first_component] = offset(value, bld, i);
2788             } else {
2789                /* We need to shuffle the 64-bit data to match the layout
2790                 * expected by our 32-bit URB write messages. We use a temporary
2791                 * for that.
2792                 */
2793                unsigned channel = iter * 2 + i;
2794                fs_reg dest = shuffle_64bit_data_for_32bit_write(bld,
2795                   offset(value, bld, channel), 1);
2796 
2797                srcs[header_regs + (i + first_component) * 2] = dest;
2798                srcs[header_regs + (i + first_component) * 2 + 1] =
2799                   offset(dest, bld, 1);
2800             }
2801          }
2802 
2803          unsigned mlen =
2804             header_regs + (is_64bit ? 2 * iter_components : iter_components) +
2805             (is_64bit ? 2 * first_component : first_component);
2806          fs_reg payload =
2807             bld.vgrf(BRW_REGISTER_TYPE_UD, mlen);
2808          bld.LOAD_PAYLOAD(payload, srcs, mlen, header_regs);
2809 
2810          fs_inst *inst = bld.emit(opcode, bld.null_reg_ud(), payload);
2811          inst->offset = imm_offset;
2812          inst->mlen = mlen;
2813 
2814          /* If this is a 64-bit attribute, select the next two 64-bit channels
2815           * to be handled in the next iteration.
2816           */
2817          if (is_64bit) {
2818             mask >>= 2;
2819             imm_offset++;
2820          }
2821       }
2822       break;
2823    }
2824 
2825    default:
2826       nir_emit_intrinsic(bld, instr);
2827       break;
2828    }
2829 }
2830 
2831 void
nir_emit_tes_intrinsic(const fs_builder & bld,nir_intrinsic_instr * instr)2832 fs_visitor::nir_emit_tes_intrinsic(const fs_builder &bld,
2833                                    nir_intrinsic_instr *instr)
2834 {
2835    assert(stage == MESA_SHADER_TESS_EVAL);
2836    struct brw_tes_prog_data *tes_prog_data = brw_tes_prog_data(prog_data);
2837 
2838    fs_reg dest;
2839    if (nir_intrinsic_infos[instr->intrinsic].has_dest)
2840       dest = get_nir_dest(instr->dest);
2841 
2842    switch (instr->intrinsic) {
2843    case nir_intrinsic_load_primitive_id:
2844       bld.MOV(dest, fs_reg(brw_vec1_grf(0, 1)));
2845       break;
2846    case nir_intrinsic_load_tess_coord:
2847       /* gl_TessCoord is part of the payload in g1-3 */
2848       for (unsigned i = 0; i < 3; i++) {
2849          bld.MOV(offset(dest, bld, i), fs_reg(brw_vec8_grf(1 + i, 0)));
2850       }
2851       break;
2852 
2853    case nir_intrinsic_load_input:
2854    case nir_intrinsic_load_per_vertex_input: {
2855       fs_reg indirect_offset = get_indirect_offset(instr);
2856       unsigned imm_offset = instr->const_index[0];
2857       unsigned first_component = nir_intrinsic_component(instr);
2858 
2859       if (type_sz(dest.type) == 8) {
2860          first_component = first_component / 2;
2861       }
2862 
2863       fs_inst *inst;
2864       if (indirect_offset.file == BAD_FILE) {
2865          /* Arbitrarily only push up to 32 vec4 slots worth of data,
2866           * which is 16 registers (since each holds 2 vec4 slots).
2867           */
2868          unsigned slot_count = 1;
2869          if (type_sz(dest.type) == 8 && instr->num_components > 2)
2870             slot_count++;
2871 
2872          const unsigned max_push_slots = 32;
2873          if (imm_offset + slot_count <= max_push_slots) {
2874             fs_reg src = fs_reg(ATTR, imm_offset / 2, dest.type);
2875             for (int i = 0; i < instr->num_components; i++) {
2876                unsigned comp = 16 / type_sz(dest.type) * (imm_offset % 2) +
2877                   i + first_component;
2878                bld.MOV(offset(dest, bld, i), component(src, comp));
2879             }
2880 
2881             tes_prog_data->base.urb_read_length =
2882                MAX2(tes_prog_data->base.urb_read_length,
2883                     DIV_ROUND_UP(imm_offset + slot_count, 2));
2884          } else {
2885             /* Replicate the patch handle to all enabled channels */
2886             const fs_reg srcs[] = {
2887                retype(brw_vec1_grf(0, 0), BRW_REGISTER_TYPE_UD)
2888             };
2889             fs_reg patch_handle = bld.vgrf(BRW_REGISTER_TYPE_UD, 1);
2890             bld.LOAD_PAYLOAD(patch_handle, srcs, ARRAY_SIZE(srcs), 0);
2891 
2892             if (first_component != 0) {
2893                unsigned read_components =
2894                   instr->num_components + first_component;
2895                fs_reg tmp = bld.vgrf(dest.type, read_components);
2896                inst = bld.emit(SHADER_OPCODE_URB_READ_SIMD8, tmp,
2897                                patch_handle);
2898                inst->size_written = read_components * REG_SIZE;
2899                for (unsigned i = 0; i < instr->num_components; i++) {
2900                   bld.MOV(offset(dest, bld, i),
2901                           offset(tmp, bld, i + first_component));
2902                }
2903             } else {
2904                inst = bld.emit(SHADER_OPCODE_URB_READ_SIMD8, dest,
2905                                patch_handle);
2906                inst->size_written = instr->num_components * REG_SIZE;
2907             }
2908             inst->mlen = 1;
2909             inst->offset = imm_offset;
2910          }
2911       } else {
2912          /* Indirect indexing - use per-slot offsets as well. */
2913 
2914          /* We can only read two double components with each URB read, so
2915           * we send two read messages in that case, each one loading up to
2916           * two double components.
2917           */
2918          unsigned num_iterations = 1;
2919          unsigned num_components = instr->num_components;
2920          fs_reg orig_dest = dest;
2921          if (type_sz(dest.type) == 8) {
2922             if (instr->num_components > 2) {
2923                num_iterations = 2;
2924                num_components = 2;
2925             }
2926             fs_reg tmp = fs_reg(VGRF, alloc.allocate(4), dest.type);
2927             dest = tmp;
2928          }
2929 
2930          for (unsigned iter = 0; iter < num_iterations; iter++) {
2931             const fs_reg srcs[] = {
2932                retype(brw_vec1_grf(0, 0), BRW_REGISTER_TYPE_UD),
2933                indirect_offset
2934             };
2935             fs_reg payload = bld.vgrf(BRW_REGISTER_TYPE_UD, 2);
2936             bld.LOAD_PAYLOAD(payload, srcs, ARRAY_SIZE(srcs), 0);
2937 
2938             if (first_component != 0) {
2939                unsigned read_components =
2940                    num_components + first_component;
2941                fs_reg tmp = bld.vgrf(dest.type, read_components);
2942                inst = bld.emit(SHADER_OPCODE_URB_READ_SIMD8_PER_SLOT, tmp,
2943                                payload);
2944                for (unsigned i = 0; i < num_components; i++) {
2945                   bld.MOV(offset(dest, bld, i),
2946                           offset(tmp, bld, i + first_component));
2947                }
2948             } else {
2949                inst = bld.emit(SHADER_OPCODE_URB_READ_SIMD8_PER_SLOT, dest,
2950                                payload);
2951             }
2952             inst->mlen = 2;
2953             inst->offset = imm_offset;
2954             inst->size_written = (num_components + first_component) *
2955                                  inst->dst.component_size(inst->exec_size);
2956 
2957             /* If we are reading 64-bit data using 32-bit read messages we need
2958              * build proper 64-bit data elements by shuffling the low and high
2959              * 32-bit components around like we do for other things like UBOs
2960              * or SSBOs.
2961              */
2962             if (type_sz(dest.type) == 8) {
2963                shuffle_32bit_load_result_to_64bit_data(
2964                   bld, dest, retype(dest, BRW_REGISTER_TYPE_F), num_components);
2965 
2966                for (unsigned c = 0; c < num_components; c++) {
2967                   bld.MOV(offset(orig_dest, bld, iter * 2 + c),
2968                           offset(dest, bld, c));
2969                }
2970             }
2971 
2972             /* If we are loading double data and we need a second read message
2973              * adjust the offset
2974              */
2975             if (num_iterations > 1) {
2976                num_components = instr->num_components - 2;
2977                imm_offset++;
2978             }
2979          }
2980       }
2981       break;
2982    }
2983    default:
2984       nir_emit_intrinsic(bld, instr);
2985       break;
2986    }
2987 }
2988 
2989 void
nir_emit_gs_intrinsic(const fs_builder & bld,nir_intrinsic_instr * instr)2990 fs_visitor::nir_emit_gs_intrinsic(const fs_builder &bld,
2991                                   nir_intrinsic_instr *instr)
2992 {
2993    assert(stage == MESA_SHADER_GEOMETRY);
2994    fs_reg indirect_offset;
2995 
2996    fs_reg dest;
2997    if (nir_intrinsic_infos[instr->intrinsic].has_dest)
2998       dest = get_nir_dest(instr->dest);
2999 
3000    switch (instr->intrinsic) {
3001    case nir_intrinsic_load_primitive_id:
3002       assert(stage == MESA_SHADER_GEOMETRY);
3003       assert(brw_gs_prog_data(prog_data)->include_primitive_id);
3004       bld.MOV(retype(dest, BRW_REGISTER_TYPE_UD),
3005               retype(fs_reg(brw_vec8_grf(2, 0)), BRW_REGISTER_TYPE_UD));
3006       break;
3007 
3008    case nir_intrinsic_load_input:
3009       unreachable("load_input intrinsics are invalid for the GS stage");
3010 
3011    case nir_intrinsic_load_per_vertex_input:
3012       emit_gs_input_load(dest, instr->src[0], instr->const_index[0],
3013                          instr->src[1], instr->num_components,
3014                          nir_intrinsic_component(instr));
3015       break;
3016 
3017    case nir_intrinsic_emit_vertex_with_counter:
3018       emit_gs_vertex(instr->src[0], instr->const_index[0]);
3019       break;
3020 
3021    case nir_intrinsic_end_primitive_with_counter:
3022       emit_gs_end_primitive(instr->src[0]);
3023       break;
3024 
3025    case nir_intrinsic_set_vertex_count:
3026       bld.MOV(this->final_gs_vertex_count, get_nir_src(instr->src[0]));
3027       break;
3028 
3029    case nir_intrinsic_load_invocation_id: {
3030       fs_reg val = nir_system_values[SYSTEM_VALUE_INVOCATION_ID];
3031       assert(val.file != BAD_FILE);
3032       dest.type = val.type;
3033       bld.MOV(dest, val);
3034       break;
3035    }
3036 
3037    default:
3038       nir_emit_intrinsic(bld, instr);
3039       break;
3040    }
3041 }
3042 
3043 /**
3044  * Fetch the current render target layer index.
3045  */
3046 static fs_reg
fetch_render_target_array_index(const fs_builder & bld)3047 fetch_render_target_array_index(const fs_builder &bld)
3048 {
3049    if (bld.shader->devinfo->gen >= 6) {
3050       /* The render target array index is provided in the thread payload as
3051        * bits 26:16 of r0.0.
3052        */
3053       const fs_reg idx = bld.vgrf(BRW_REGISTER_TYPE_UD);
3054       bld.AND(idx, brw_uw1_reg(BRW_GENERAL_REGISTER_FILE, 0, 1),
3055               brw_imm_uw(0x7ff));
3056       return idx;
3057    } else {
3058       /* Pre-SNB we only ever render into the first layer of the framebuffer
3059        * since layered rendering is not implemented.
3060        */
3061       return brw_imm_ud(0);
3062    }
3063 }
3064 
3065 /**
3066  * Fake non-coherent framebuffer read implemented using TXF to fetch from the
3067  * framebuffer at the current fragment coordinates and sample index.
3068  */
3069 fs_inst *
emit_non_coherent_fb_read(const fs_builder & bld,const fs_reg & dst,unsigned target)3070 fs_visitor::emit_non_coherent_fb_read(const fs_builder &bld, const fs_reg &dst,
3071                                       unsigned target)
3072 {
3073    const struct gen_device_info *devinfo = bld.shader->devinfo;
3074 
3075    assert(bld.shader->stage == MESA_SHADER_FRAGMENT);
3076    const brw_wm_prog_key *wm_key =
3077       reinterpret_cast<const brw_wm_prog_key *>(key);
3078    assert(!wm_key->coherent_fb_fetch);
3079    const struct brw_wm_prog_data *wm_prog_data =
3080       brw_wm_prog_data(stage_prog_data);
3081 
3082    /* Calculate the surface index relative to the start of the texture binding
3083     * table block, since that's what the texturing messages expect.
3084     */
3085    const unsigned surface = target +
3086       wm_prog_data->binding_table.render_target_read_start -
3087       wm_prog_data->base.binding_table.texture_start;
3088 
3089    brw_mark_surface_used(
3090       bld.shader->stage_prog_data,
3091       wm_prog_data->binding_table.render_target_read_start + target);
3092 
3093    /* Calculate the fragment coordinates. */
3094    const fs_reg coords = bld.vgrf(BRW_REGISTER_TYPE_UD, 3);
3095    bld.MOV(offset(coords, bld, 0), pixel_x);
3096    bld.MOV(offset(coords, bld, 1), pixel_y);
3097    bld.MOV(offset(coords, bld, 2), fetch_render_target_array_index(bld));
3098 
3099    /* Calculate the sample index and MCS payload when multisampling.  Luckily
3100     * the MCS fetch message behaves deterministically for UMS surfaces, so it
3101     * shouldn't be necessary to recompile based on whether the framebuffer is
3102     * CMS or UMS.
3103     */
3104    if (wm_key->multisample_fbo &&
3105        nir_system_values[SYSTEM_VALUE_SAMPLE_ID].file == BAD_FILE)
3106       nir_system_values[SYSTEM_VALUE_SAMPLE_ID] = *emit_sampleid_setup();
3107 
3108    const fs_reg sample = nir_system_values[SYSTEM_VALUE_SAMPLE_ID];
3109    const fs_reg mcs = wm_key->multisample_fbo ?
3110       emit_mcs_fetch(coords, 3, brw_imm_ud(surface)) : fs_reg();
3111 
3112    /* Use either a normal or a CMS texel fetch message depending on whether
3113     * the framebuffer is single or multisample.  On SKL+ use the wide CMS
3114     * message just in case the framebuffer uses 16x multisampling, it should
3115     * be equivalent to the normal CMS fetch for lower multisampling modes.
3116     */
3117    const opcode op = !wm_key->multisample_fbo ? SHADER_OPCODE_TXF_LOGICAL :
3118                      devinfo->gen >= 9 ? SHADER_OPCODE_TXF_CMS_W_LOGICAL :
3119                      SHADER_OPCODE_TXF_CMS_LOGICAL;
3120 
3121    /* Emit the instruction. */
3122    const fs_reg srcs[] = { coords, fs_reg(), brw_imm_ud(0), fs_reg(),
3123                            sample, mcs,
3124                            brw_imm_ud(surface), brw_imm_ud(0),
3125                            fs_reg(), brw_imm_ud(3), brw_imm_ud(0) };
3126    STATIC_ASSERT(ARRAY_SIZE(srcs) == TEX_LOGICAL_NUM_SRCS);
3127 
3128    fs_inst *inst = bld.emit(op, dst, srcs, ARRAY_SIZE(srcs));
3129    inst->size_written = 4 * inst->dst.component_size(inst->exec_size);
3130 
3131    return inst;
3132 }
3133 
3134 /**
3135  * Actual coherent framebuffer read implemented using the native render target
3136  * read message.  Requires SKL+.
3137  */
3138 static fs_inst *
emit_coherent_fb_read(const fs_builder & bld,const fs_reg & dst,unsigned target)3139 emit_coherent_fb_read(const fs_builder &bld, const fs_reg &dst, unsigned target)
3140 {
3141    assert(bld.shader->devinfo->gen >= 9);
3142    fs_inst *inst = bld.emit(FS_OPCODE_FB_READ_LOGICAL, dst);
3143    inst->target = target;
3144    inst->size_written = 4 * inst->dst.component_size(inst->exec_size);
3145 
3146    return inst;
3147 }
3148 
3149 static fs_reg
alloc_temporary(const fs_builder & bld,unsigned size,fs_reg * regs,unsigned n)3150 alloc_temporary(const fs_builder &bld, unsigned size, fs_reg *regs, unsigned n)
3151 {
3152    if (n && regs[0].file != BAD_FILE) {
3153       return regs[0];
3154 
3155    } else {
3156       const fs_reg tmp = bld.vgrf(BRW_REGISTER_TYPE_F, size);
3157 
3158       for (unsigned i = 0; i < n; i++)
3159          regs[i] = tmp;
3160 
3161       return tmp;
3162    }
3163 }
3164 
3165 static fs_reg
alloc_frag_output(fs_visitor * v,unsigned location)3166 alloc_frag_output(fs_visitor *v, unsigned location)
3167 {
3168    assert(v->stage == MESA_SHADER_FRAGMENT);
3169    const brw_wm_prog_key *const key =
3170       reinterpret_cast<const brw_wm_prog_key *>(v->key);
3171    const unsigned l = GET_FIELD(location, BRW_NIR_FRAG_OUTPUT_LOCATION);
3172    const unsigned i = GET_FIELD(location, BRW_NIR_FRAG_OUTPUT_INDEX);
3173 
3174    if (i > 0 || (key->force_dual_color_blend && l == FRAG_RESULT_DATA1))
3175       return alloc_temporary(v->bld, 4, &v->dual_src_output, 1);
3176 
3177    else if (l == FRAG_RESULT_COLOR)
3178       return alloc_temporary(v->bld, 4, v->outputs,
3179                              MAX2(key->nr_color_regions, 1));
3180 
3181    else if (l == FRAG_RESULT_DEPTH)
3182       return alloc_temporary(v->bld, 1, &v->frag_depth, 1);
3183 
3184    else if (l == FRAG_RESULT_STENCIL)
3185       return alloc_temporary(v->bld, 1, &v->frag_stencil, 1);
3186 
3187    else if (l == FRAG_RESULT_SAMPLE_MASK)
3188       return alloc_temporary(v->bld, 1, &v->sample_mask, 1);
3189 
3190    else if (l >= FRAG_RESULT_DATA0 &&
3191             l < FRAG_RESULT_DATA0 + BRW_MAX_DRAW_BUFFERS)
3192       return alloc_temporary(v->bld, 4,
3193                              &v->outputs[l - FRAG_RESULT_DATA0], 1);
3194 
3195    else
3196       unreachable("Invalid location");
3197 }
3198 
3199 void
nir_emit_fs_intrinsic(const fs_builder & bld,nir_intrinsic_instr * instr)3200 fs_visitor::nir_emit_fs_intrinsic(const fs_builder &bld,
3201                                   nir_intrinsic_instr *instr)
3202 {
3203    assert(stage == MESA_SHADER_FRAGMENT);
3204 
3205    fs_reg dest;
3206    if (nir_intrinsic_infos[instr->intrinsic].has_dest)
3207       dest = get_nir_dest(instr->dest);
3208 
3209    switch (instr->intrinsic) {
3210    case nir_intrinsic_load_front_face:
3211       bld.MOV(retype(dest, BRW_REGISTER_TYPE_D),
3212               *emit_frontfacing_interpolation());
3213       break;
3214 
3215    case nir_intrinsic_load_sample_pos: {
3216       fs_reg sample_pos = nir_system_values[SYSTEM_VALUE_SAMPLE_POS];
3217       assert(sample_pos.file != BAD_FILE);
3218       dest.type = sample_pos.type;
3219       bld.MOV(dest, sample_pos);
3220       bld.MOV(offset(dest, bld, 1), offset(sample_pos, bld, 1));
3221       break;
3222    }
3223 
3224    case nir_intrinsic_load_layer_id:
3225       dest.type = BRW_REGISTER_TYPE_UD;
3226       bld.MOV(dest, fetch_render_target_array_index(bld));
3227       break;
3228 
3229    case nir_intrinsic_load_helper_invocation:
3230    case nir_intrinsic_load_sample_mask_in:
3231    case nir_intrinsic_load_sample_id: {
3232       gl_system_value sv = nir_system_value_from_intrinsic(instr->intrinsic);
3233       fs_reg val = nir_system_values[sv];
3234       assert(val.file != BAD_FILE);
3235       dest.type = val.type;
3236       bld.MOV(dest, val);
3237       break;
3238    }
3239 
3240    case nir_intrinsic_store_output: {
3241       const fs_reg src = get_nir_src(instr->src[0]);
3242       const nir_const_value *const_offset = nir_src_as_const_value(instr->src[1]);
3243       assert(const_offset && "Indirect output stores not allowed");
3244       const unsigned location = nir_intrinsic_base(instr) +
3245          SET_FIELD(const_offset->u32[0], BRW_NIR_FRAG_OUTPUT_LOCATION);
3246       const fs_reg new_dest = retype(alloc_frag_output(this, location),
3247                                      src.type);
3248 
3249       for (unsigned j = 0; j < instr->num_components; j++)
3250          bld.MOV(offset(new_dest, bld, nir_intrinsic_component(instr) + j),
3251                  offset(src, bld, j));
3252 
3253       break;
3254    }
3255 
3256    case nir_intrinsic_load_output: {
3257       const unsigned l = GET_FIELD(nir_intrinsic_base(instr),
3258                                    BRW_NIR_FRAG_OUTPUT_LOCATION);
3259       assert(l >= FRAG_RESULT_DATA0);
3260       nir_const_value *const_offset = nir_src_as_const_value(instr->src[0]);
3261       assert(const_offset && "Indirect output loads not allowed");
3262       const unsigned target = l - FRAG_RESULT_DATA0 + const_offset->u32[0];
3263       const fs_reg tmp = bld.vgrf(dest.type, 4);
3264 
3265       if (reinterpret_cast<const brw_wm_prog_key *>(key)->coherent_fb_fetch)
3266          emit_coherent_fb_read(bld, tmp, target);
3267       else
3268          emit_non_coherent_fb_read(bld, tmp, target);
3269 
3270       for (unsigned j = 0; j < instr->num_components; j++) {
3271          bld.MOV(offset(dest, bld, j),
3272                  offset(tmp, bld, nir_intrinsic_component(instr) + j));
3273       }
3274 
3275       break;
3276    }
3277 
3278    case nir_intrinsic_discard:
3279    case nir_intrinsic_discard_if: {
3280       /* We track our discarded pixels in f0.1.  By predicating on it, we can
3281        * update just the flag bits that aren't yet discarded.  If there's no
3282        * condition, we emit a CMP of g0 != g0, so all currently executing
3283        * channels will get turned off.
3284        */
3285       fs_inst *cmp;
3286       if (instr->intrinsic == nir_intrinsic_discard_if) {
3287          cmp = bld.CMP(bld.null_reg_f(), get_nir_src(instr->src[0]),
3288                        brw_imm_d(0), BRW_CONDITIONAL_Z);
3289       } else {
3290          fs_reg some_reg = fs_reg(retype(brw_vec8_grf(0, 0),
3291                                        BRW_REGISTER_TYPE_UW));
3292          cmp = bld.CMP(bld.null_reg_f(), some_reg, some_reg, BRW_CONDITIONAL_NZ);
3293       }
3294       cmp->predicate = BRW_PREDICATE_NORMAL;
3295       cmp->flag_subreg = 1;
3296 
3297       if (devinfo->gen >= 6) {
3298          emit_discard_jump();
3299       }
3300       break;
3301    }
3302 
3303    case nir_intrinsic_load_input: {
3304       /* load_input is only used for flat inputs */
3305       unsigned base = nir_intrinsic_base(instr);
3306       unsigned component = nir_intrinsic_component(instr);
3307       unsigned num_components = instr->num_components;
3308       enum brw_reg_type type = dest.type;
3309 
3310       /* Special case fields in the VUE header */
3311       if (base == VARYING_SLOT_LAYER)
3312          component = 1;
3313       else if (base == VARYING_SLOT_VIEWPORT)
3314          component = 2;
3315 
3316       if (nir_dest_bit_size(instr->dest) == 64) {
3317          /* const_index is in 32-bit type size units that could not be aligned
3318           * with DF. We need to read the double vector as if it was a float
3319           * vector of twice the number of components to fetch the right data.
3320           */
3321          type = BRW_REGISTER_TYPE_F;
3322          num_components *= 2;
3323       }
3324 
3325       for (unsigned int i = 0; i < num_components; i++) {
3326          struct brw_reg interp = interp_reg(base, component + i);
3327          interp = suboffset(interp, 3);
3328          bld.emit(FS_OPCODE_CINTERP, offset(retype(dest, type), bld, i),
3329                   retype(fs_reg(interp), type));
3330       }
3331 
3332       if (nir_dest_bit_size(instr->dest) == 64) {
3333          shuffle_32bit_load_result_to_64bit_data(bld,
3334                                                  dest,
3335                                                  retype(dest, type),
3336                                                  instr->num_components);
3337       }
3338       break;
3339    }
3340 
3341    case nir_intrinsic_load_barycentric_pixel:
3342    case nir_intrinsic_load_barycentric_centroid:
3343    case nir_intrinsic_load_barycentric_sample:
3344       /* Do nothing - load_interpolated_input handling will handle it later. */
3345       break;
3346 
3347    case nir_intrinsic_load_barycentric_at_sample: {
3348       const glsl_interp_mode interpolation =
3349          (enum glsl_interp_mode) nir_intrinsic_interp_mode(instr);
3350 
3351       nir_const_value *const_sample = nir_src_as_const_value(instr->src[0]);
3352 
3353       if (const_sample) {
3354          unsigned msg_data = const_sample->i32[0] << 4;
3355 
3356          emit_pixel_interpolater_send(bld,
3357                                       FS_OPCODE_INTERPOLATE_AT_SAMPLE,
3358                                       dest,
3359                                       fs_reg(), /* src */
3360                                       brw_imm_ud(msg_data),
3361                                       interpolation);
3362       } else {
3363          const fs_reg sample_src = retype(get_nir_src(instr->src[0]),
3364                                           BRW_REGISTER_TYPE_UD);
3365 
3366          if (nir_src_is_dynamically_uniform(instr->src[0])) {
3367             const fs_reg sample_id = bld.emit_uniformize(sample_src);
3368             const fs_reg msg_data = vgrf(glsl_type::uint_type);
3369             bld.exec_all().group(1, 0)
3370                .SHL(msg_data, sample_id, brw_imm_ud(4u));
3371             emit_pixel_interpolater_send(bld,
3372                                          FS_OPCODE_INTERPOLATE_AT_SAMPLE,
3373                                          dest,
3374                                          fs_reg(), /* src */
3375                                          msg_data,
3376                                          interpolation);
3377          } else {
3378             /* Make a loop that sends a message to the pixel interpolater
3379              * for the sample number in each live channel. If there are
3380              * multiple channels with the same sample number then these
3381              * will be handled simultaneously with a single interation of
3382              * the loop.
3383              */
3384             bld.emit(BRW_OPCODE_DO);
3385 
3386             /* Get the next live sample number into sample_id_reg */
3387             const fs_reg sample_id = bld.emit_uniformize(sample_src);
3388 
3389             /* Set the flag register so that we can perform the send
3390              * message on all channels that have the same sample number
3391              */
3392             bld.CMP(bld.null_reg_ud(),
3393                     sample_src, sample_id,
3394                     BRW_CONDITIONAL_EQ);
3395             const fs_reg msg_data = vgrf(glsl_type::uint_type);
3396             bld.exec_all().group(1, 0)
3397                .SHL(msg_data, sample_id, brw_imm_ud(4u));
3398             fs_inst *inst =
3399                emit_pixel_interpolater_send(bld,
3400                                             FS_OPCODE_INTERPOLATE_AT_SAMPLE,
3401                                             dest,
3402                                             fs_reg(), /* src */
3403                                             msg_data,
3404                                             interpolation);
3405             set_predicate(BRW_PREDICATE_NORMAL, inst);
3406 
3407             /* Continue the loop if there are any live channels left */
3408             set_predicate_inv(BRW_PREDICATE_NORMAL,
3409                               true, /* inverse */
3410                               bld.emit(BRW_OPCODE_WHILE));
3411          }
3412       }
3413       break;
3414    }
3415 
3416    case nir_intrinsic_load_barycentric_at_offset: {
3417       const glsl_interp_mode interpolation =
3418          (enum glsl_interp_mode) nir_intrinsic_interp_mode(instr);
3419 
3420       nir_const_value *const_offset = nir_src_as_const_value(instr->src[0]);
3421 
3422       if (const_offset) {
3423          unsigned off_x = MIN2((int)(const_offset->f32[0] * 16), 7) & 0xf;
3424          unsigned off_y = MIN2((int)(const_offset->f32[1] * 16), 7) & 0xf;
3425 
3426          emit_pixel_interpolater_send(bld,
3427                                       FS_OPCODE_INTERPOLATE_AT_SHARED_OFFSET,
3428                                       dest,
3429                                       fs_reg(), /* src */
3430                                       brw_imm_ud(off_x | (off_y << 4)),
3431                                       interpolation);
3432       } else {
3433          fs_reg src = vgrf(glsl_type::ivec2_type);
3434          fs_reg offset_src = retype(get_nir_src(instr->src[0]),
3435                                     BRW_REGISTER_TYPE_F);
3436          for (int i = 0; i < 2; i++) {
3437             fs_reg temp = vgrf(glsl_type::float_type);
3438             bld.MUL(temp, offset(offset_src, bld, i), brw_imm_f(16.0f));
3439             fs_reg itemp = vgrf(glsl_type::int_type);
3440             /* float to int */
3441             bld.MOV(itemp, temp);
3442 
3443             /* Clamp the upper end of the range to +7/16.
3444              * ARB_gpu_shader5 requires that we support a maximum offset
3445              * of +0.5, which isn't representable in a S0.4 value -- if
3446              * we didn't clamp it, we'd end up with -8/16, which is the
3447              * opposite of what the shader author wanted.
3448              *
3449              * This is legal due to ARB_gpu_shader5's quantization
3450              * rules:
3451              *
3452              * "Not all values of <offset> may be supported; x and y
3453              * offsets may be rounded to fixed-point values with the
3454              * number of fraction bits given by the
3455              * implementation-dependent constant
3456              * FRAGMENT_INTERPOLATION_OFFSET_BITS"
3457              */
3458             set_condmod(BRW_CONDITIONAL_L,
3459                         bld.SEL(offset(src, bld, i), itemp, brw_imm_d(7)));
3460          }
3461 
3462          const enum opcode opcode = FS_OPCODE_INTERPOLATE_AT_PER_SLOT_OFFSET;
3463          emit_pixel_interpolater_send(bld,
3464                                       opcode,
3465                                       dest,
3466                                       src,
3467                                       brw_imm_ud(0u),
3468                                       interpolation);
3469       }
3470       break;
3471    }
3472 
3473    case nir_intrinsic_load_interpolated_input: {
3474       if (nir_intrinsic_base(instr) == VARYING_SLOT_POS) {
3475          emit_fragcoord_interpolation(dest);
3476          break;
3477       }
3478 
3479       assert(instr->src[0].ssa &&
3480              instr->src[0].ssa->parent_instr->type == nir_instr_type_intrinsic);
3481       nir_intrinsic_instr *bary_intrinsic =
3482          nir_instr_as_intrinsic(instr->src[0].ssa->parent_instr);
3483       nir_intrinsic_op bary_intrin = bary_intrinsic->intrinsic;
3484       enum glsl_interp_mode interp_mode =
3485          (enum glsl_interp_mode) nir_intrinsic_interp_mode(bary_intrinsic);
3486       fs_reg dst_xy;
3487 
3488       if (bary_intrin == nir_intrinsic_load_barycentric_at_offset ||
3489           bary_intrin == nir_intrinsic_load_barycentric_at_sample) {
3490          /* Use the result of the PI message */
3491          dst_xy = retype(get_nir_src(instr->src[0]), BRW_REGISTER_TYPE_F);
3492       } else {
3493          /* Use the delta_xy values computed from the payload */
3494          enum brw_barycentric_mode bary =
3495             brw_barycentric_mode(interp_mode, bary_intrin);
3496 
3497          dst_xy = this->delta_xy[bary];
3498       }
3499 
3500       for (unsigned int i = 0; i < instr->num_components; i++) {
3501          fs_reg interp =
3502             fs_reg(interp_reg(nir_intrinsic_base(instr),
3503                               nir_intrinsic_component(instr) + i));
3504          interp.type = BRW_REGISTER_TYPE_F;
3505          dest.type = BRW_REGISTER_TYPE_F;
3506 
3507          if (devinfo->gen < 6 && interp_mode == INTERP_MODE_SMOOTH) {
3508             fs_reg tmp = vgrf(glsl_type::float_type);
3509             bld.emit(FS_OPCODE_LINTERP, tmp, dst_xy, interp);
3510             bld.MUL(offset(dest, bld, i), tmp, this->pixel_w);
3511          } else {
3512             bld.emit(FS_OPCODE_LINTERP, offset(dest, bld, i), dst_xy, interp);
3513          }
3514       }
3515       break;
3516    }
3517 
3518    default:
3519       nir_emit_intrinsic(bld, instr);
3520       break;
3521    }
3522 }
3523 
3524 void
nir_emit_cs_intrinsic(const fs_builder & bld,nir_intrinsic_instr * instr)3525 fs_visitor::nir_emit_cs_intrinsic(const fs_builder &bld,
3526                                   nir_intrinsic_instr *instr)
3527 {
3528    assert(stage == MESA_SHADER_COMPUTE);
3529    struct brw_cs_prog_data *cs_prog_data = brw_cs_prog_data(prog_data);
3530 
3531    fs_reg dest;
3532    if (nir_intrinsic_infos[instr->intrinsic].has_dest)
3533       dest = get_nir_dest(instr->dest);
3534 
3535    switch (instr->intrinsic) {
3536    case nir_intrinsic_barrier:
3537       emit_barrier();
3538       cs_prog_data->uses_barrier = true;
3539       break;
3540 
3541    case nir_intrinsic_load_subgroup_id:
3542       bld.MOV(retype(dest, BRW_REGISTER_TYPE_UD), subgroup_id);
3543       break;
3544 
3545    case nir_intrinsic_load_local_invocation_id:
3546    case nir_intrinsic_load_work_group_id: {
3547       gl_system_value sv = nir_system_value_from_intrinsic(instr->intrinsic);
3548       fs_reg val = nir_system_values[sv];
3549       assert(val.file != BAD_FILE);
3550       dest.type = val.type;
3551       for (unsigned i = 0; i < 3; i++)
3552          bld.MOV(offset(dest, bld, i), offset(val, bld, i));
3553       break;
3554    }
3555 
3556    case nir_intrinsic_load_num_work_groups: {
3557       const unsigned surface =
3558          cs_prog_data->binding_table.work_groups_start;
3559 
3560       cs_prog_data->uses_num_work_groups = true;
3561 
3562       fs_reg surf_index = brw_imm_ud(surface);
3563       brw_mark_surface_used(prog_data, surface);
3564 
3565       /* Read the 3 GLuint components of gl_NumWorkGroups */
3566       for (unsigned i = 0; i < 3; i++) {
3567          fs_reg read_result =
3568             emit_untyped_read(bld, surf_index,
3569                               brw_imm_ud(i << 2),
3570                               1 /* dims */, 1 /* size */,
3571                               BRW_PREDICATE_NONE);
3572          read_result.type = dest.type;
3573          bld.MOV(dest, read_result);
3574          dest = offset(dest, bld, 1);
3575       }
3576       break;
3577    }
3578 
3579    case nir_intrinsic_shared_atomic_add:
3580       nir_emit_shared_atomic(bld, BRW_AOP_ADD, instr);
3581       break;
3582    case nir_intrinsic_shared_atomic_imin:
3583       nir_emit_shared_atomic(bld, BRW_AOP_IMIN, instr);
3584       break;
3585    case nir_intrinsic_shared_atomic_umin:
3586       nir_emit_shared_atomic(bld, BRW_AOP_UMIN, instr);
3587       break;
3588    case nir_intrinsic_shared_atomic_imax:
3589       nir_emit_shared_atomic(bld, BRW_AOP_IMAX, instr);
3590       break;
3591    case nir_intrinsic_shared_atomic_umax:
3592       nir_emit_shared_atomic(bld, BRW_AOP_UMAX, instr);
3593       break;
3594    case nir_intrinsic_shared_atomic_and:
3595       nir_emit_shared_atomic(bld, BRW_AOP_AND, instr);
3596       break;
3597    case nir_intrinsic_shared_atomic_or:
3598       nir_emit_shared_atomic(bld, BRW_AOP_OR, instr);
3599       break;
3600    case nir_intrinsic_shared_atomic_xor:
3601       nir_emit_shared_atomic(bld, BRW_AOP_XOR, instr);
3602       break;
3603    case nir_intrinsic_shared_atomic_exchange:
3604       nir_emit_shared_atomic(bld, BRW_AOP_MOV, instr);
3605       break;
3606    case nir_intrinsic_shared_atomic_comp_swap:
3607       nir_emit_shared_atomic(bld, BRW_AOP_CMPWR, instr);
3608       break;
3609 
3610    case nir_intrinsic_load_shared: {
3611       assert(devinfo->gen >= 7);
3612 
3613       fs_reg surf_index = brw_imm_ud(GEN7_BTI_SLM);
3614 
3615       /* Get the offset to read from */
3616       fs_reg offset_reg;
3617       nir_const_value *const_offset = nir_src_as_const_value(instr->src[0]);
3618       if (const_offset) {
3619          offset_reg = brw_imm_ud(instr->const_index[0] + const_offset->u32[0]);
3620       } else {
3621          offset_reg = vgrf(glsl_type::uint_type);
3622          bld.ADD(offset_reg,
3623                  retype(get_nir_src(instr->src[0]), BRW_REGISTER_TYPE_UD),
3624                  brw_imm_ud(instr->const_index[0]));
3625       }
3626 
3627       /* Read the vector */
3628       do_untyped_vector_read(bld, dest, surf_index, offset_reg,
3629                              instr->num_components);
3630       break;
3631    }
3632 
3633    case nir_intrinsic_store_shared: {
3634       assert(devinfo->gen >= 7);
3635 
3636       /* Block index */
3637       fs_reg surf_index = brw_imm_ud(GEN7_BTI_SLM);
3638 
3639       /* Value */
3640       fs_reg val_reg = get_nir_src(instr->src[0]);
3641 
3642       /* Writemask */
3643       unsigned writemask = instr->const_index[1];
3644 
3645       /* get_nir_src() retypes to integer. Be wary of 64-bit types though
3646        * since the untyped writes below operate in units of 32-bits, which
3647        * means that we need to write twice as many components each time.
3648        * Also, we have to suffle 64-bit data to be in the appropriate layout
3649        * expected by our 32-bit write messages.
3650        */
3651       unsigned type_size = 4;
3652       if (nir_src_bit_size(instr->src[0]) == 64) {
3653          type_size = 8;
3654          val_reg = shuffle_64bit_data_for_32bit_write(bld,
3655             val_reg, instr->num_components);
3656       }
3657 
3658       unsigned type_slots = type_size / 4;
3659 
3660       /* Combine groups of consecutive enabled channels in one write
3661        * message. We use ffs to find the first enabled channel and then ffs on
3662        * the bit-inverse, down-shifted writemask to determine the length of
3663        * the block of enabled bits.
3664        */
3665       while (writemask) {
3666          unsigned first_component = ffs(writemask) - 1;
3667          unsigned length = ffs(~(writemask >> first_component)) - 1;
3668 
3669          /* We can't write more than 2 64-bit components at once. Limit the
3670           * length of the write to what we can do and let the next iteration
3671           * handle the rest
3672           */
3673          if (type_size > 4)
3674             length = MIN2(2, length);
3675 
3676          fs_reg offset_reg;
3677          nir_const_value *const_offset = nir_src_as_const_value(instr->src[1]);
3678          if (const_offset) {
3679             offset_reg = brw_imm_ud(instr->const_index[0] + const_offset->u32[0] +
3680                                     type_size * first_component);
3681          } else {
3682             offset_reg = vgrf(glsl_type::uint_type);
3683             bld.ADD(offset_reg,
3684                     retype(get_nir_src(instr->src[1]), BRW_REGISTER_TYPE_UD),
3685                     brw_imm_ud(instr->const_index[0] + type_size * first_component));
3686          }
3687 
3688          emit_untyped_write(bld, surf_index, offset_reg,
3689                             offset(val_reg, bld, first_component * type_slots),
3690                             1 /* dims */, length * type_slots,
3691                             BRW_PREDICATE_NONE);
3692 
3693          /* Clear the bits in the writemask that we just wrote, then try
3694           * again to see if more channels are left.
3695           */
3696          writemask &= (15 << (first_component + length));
3697       }
3698 
3699       break;
3700    }
3701 
3702    default:
3703       nir_emit_intrinsic(bld, instr);
3704       break;
3705    }
3706 }
3707 
3708 void
nir_emit_intrinsic(const fs_builder & bld,nir_intrinsic_instr * instr)3709 fs_visitor::nir_emit_intrinsic(const fs_builder &bld, nir_intrinsic_instr *instr)
3710 {
3711    fs_reg dest;
3712    if (nir_intrinsic_infos[instr->intrinsic].has_dest)
3713       dest = get_nir_dest(instr->dest);
3714 
3715    switch (instr->intrinsic) {
3716    case nir_intrinsic_image_load:
3717    case nir_intrinsic_image_store:
3718    case nir_intrinsic_image_atomic_add:
3719    case nir_intrinsic_image_atomic_min:
3720    case nir_intrinsic_image_atomic_max:
3721    case nir_intrinsic_image_atomic_and:
3722    case nir_intrinsic_image_atomic_or:
3723    case nir_intrinsic_image_atomic_xor:
3724    case nir_intrinsic_image_atomic_exchange:
3725    case nir_intrinsic_image_atomic_comp_swap: {
3726       using namespace image_access;
3727 
3728       if (stage == MESA_SHADER_FRAGMENT &&
3729           instr->intrinsic != nir_intrinsic_image_load)
3730          brw_wm_prog_data(prog_data)->has_side_effects = true;
3731 
3732       /* Get the referenced image variable and type. */
3733       const nir_variable *var = instr->variables[0]->var;
3734       const glsl_type *type = var->type->without_array();
3735       const brw_reg_type base_type = get_image_base_type(type);
3736 
3737       /* Get some metadata from the image intrinsic. */
3738       const nir_intrinsic_info *info = &nir_intrinsic_infos[instr->intrinsic];
3739       const unsigned arr_dims = type->sampler_array ? 1 : 0;
3740       const unsigned surf_dims = type->coordinate_components() - arr_dims;
3741       const unsigned format = var->data.image.format;
3742 
3743       /* Get the arguments of the image intrinsic. */
3744       const fs_reg image = get_nir_image_deref(instr->variables[0]);
3745       const fs_reg addr = retype(get_nir_src(instr->src[0]),
3746                                  BRW_REGISTER_TYPE_UD);
3747       const fs_reg src0 = (info->num_srcs >= 3 ?
3748                            retype(get_nir_src(instr->src[2]), base_type) :
3749                            fs_reg());
3750       const fs_reg src1 = (info->num_srcs >= 4 ?
3751                            retype(get_nir_src(instr->src[3]), base_type) :
3752                            fs_reg());
3753       fs_reg tmp;
3754 
3755       /* Emit an image load, store or atomic op. */
3756       if (instr->intrinsic == nir_intrinsic_image_load)
3757          tmp = emit_image_load(bld, image, addr, surf_dims, arr_dims, format);
3758 
3759       else if (instr->intrinsic == nir_intrinsic_image_store)
3760          emit_image_store(bld, image, addr, src0, surf_dims, arr_dims,
3761                           var->data.image.write_only ? GL_NONE : format);
3762 
3763       else
3764          tmp = emit_image_atomic(bld, image, addr, src0, src1,
3765                                  surf_dims, arr_dims, info->dest_components,
3766                                  get_image_atomic_op(instr->intrinsic, type));
3767 
3768       /* Assign the result. */
3769       for (unsigned c = 0; c < info->dest_components; ++c)
3770          bld.MOV(offset(retype(dest, base_type), bld, c),
3771                  offset(tmp, bld, c));
3772       break;
3773    }
3774 
3775    case nir_intrinsic_memory_barrier_atomic_counter:
3776    case nir_intrinsic_memory_barrier_buffer:
3777    case nir_intrinsic_memory_barrier_image:
3778    case nir_intrinsic_memory_barrier: {
3779       const fs_builder ubld = bld.group(8, 0);
3780       const fs_reg tmp = ubld.vgrf(BRW_REGISTER_TYPE_UD, 2);
3781       ubld.emit(SHADER_OPCODE_MEMORY_FENCE, tmp)
3782          ->size_written = 2 * REG_SIZE;
3783       break;
3784    }
3785 
3786    case nir_intrinsic_group_memory_barrier:
3787    case nir_intrinsic_memory_barrier_shared:
3788       /* We treat these workgroup-level barriers as no-ops.  This should be
3789        * safe at present and as long as:
3790        *
3791        *  - Memory access instructions are not subsequently reordered by the
3792        *    compiler back-end.
3793        *
3794        *  - All threads from a given compute shader workgroup fit within a
3795        *    single subslice and therefore talk to the same HDC shared unit
3796        *    what supposedly guarantees ordering and coherency between threads
3797        *    from the same workgroup.  This may change in the future when we
3798        *    start splitting workgroups across multiple subslices.
3799        *
3800        *  - The context is not in fault-and-stream mode, which could cause
3801        *    memory transactions (including to SLM) prior to the barrier to be
3802        *    replayed after the barrier if a pagefault occurs.  This shouldn't
3803        *    be a problem up to and including SKL because fault-and-stream is
3804        *    not usable due to hardware issues, but that's likely to change in
3805        *    the future.
3806        */
3807       break;
3808 
3809    case nir_intrinsic_shader_clock: {
3810       /* We cannot do anything if there is an event, so ignore it for now */
3811       const fs_reg shader_clock = get_timestamp(bld);
3812       const fs_reg srcs[] = { component(shader_clock, 0),
3813                               component(shader_clock, 1) };
3814       bld.LOAD_PAYLOAD(dest, srcs, ARRAY_SIZE(srcs), 0);
3815       break;
3816    }
3817 
3818    case nir_intrinsic_image_size: {
3819       /* Get the referenced image variable and type. */
3820       const nir_variable *var = instr->variables[0]->var;
3821       const glsl_type *type = var->type->without_array();
3822 
3823       /* Get the size of the image. */
3824       const fs_reg image = get_nir_image_deref(instr->variables[0]);
3825       const fs_reg size = offset(image, bld, BRW_IMAGE_PARAM_SIZE_OFFSET);
3826 
3827       /* For 1DArray image types, the array index is stored in the Z component.
3828        * Fix this by swizzling the Z component to the Y component.
3829        */
3830       const bool is_1d_array_image =
3831                   type->sampler_dimensionality == GLSL_SAMPLER_DIM_1D &&
3832                   type->sampler_array;
3833 
3834       /* For CubeArray images, we should count the number of cubes instead
3835        * of the number of faces. Fix it by dividing the (Z component) by 6.
3836        */
3837       const bool is_cube_array_image =
3838                   type->sampler_dimensionality == GLSL_SAMPLER_DIM_CUBE &&
3839                   type->sampler_array;
3840 
3841       /* Copy all the components. */
3842       for (unsigned c = 0; c < instr->dest.ssa.num_components; ++c) {
3843          if ((int)c >= type->coordinate_components()) {
3844              bld.MOV(offset(retype(dest, BRW_REGISTER_TYPE_D), bld, c),
3845                      brw_imm_d(1));
3846          } else if (c == 1 && is_1d_array_image) {
3847             bld.MOV(offset(retype(dest, BRW_REGISTER_TYPE_D), bld, c),
3848                     offset(size, bld, 2));
3849          } else if (c == 2 && is_cube_array_image) {
3850             bld.emit(SHADER_OPCODE_INT_QUOTIENT,
3851                      offset(retype(dest, BRW_REGISTER_TYPE_D), bld, c),
3852                      offset(size, bld, c), brw_imm_d(6));
3853          } else {
3854             bld.MOV(offset(retype(dest, BRW_REGISTER_TYPE_D), bld, c),
3855                     offset(size, bld, c));
3856          }
3857        }
3858 
3859       break;
3860    }
3861 
3862    case nir_intrinsic_image_samples:
3863       /* The driver does not support multi-sampled images. */
3864       bld.MOV(retype(dest, BRW_REGISTER_TYPE_D), brw_imm_d(1));
3865       break;
3866 
3867    case nir_intrinsic_load_uniform: {
3868       /* Offsets are in bytes but they should always be multiples of 4 */
3869       assert(instr->const_index[0] % 4 == 0);
3870 
3871       fs_reg src(UNIFORM, instr->const_index[0] / 4, dest.type);
3872 
3873       nir_const_value *const_offset = nir_src_as_const_value(instr->src[0]);
3874       if (const_offset) {
3875          /* Offsets are in bytes but they should always be multiples of 4 */
3876          assert(const_offset->u32[0] % 4 == 0);
3877          src.offset = const_offset->u32[0];
3878 
3879          for (unsigned j = 0; j < instr->num_components; j++) {
3880             bld.MOV(offset(dest, bld, j), offset(src, bld, j));
3881          }
3882       } else {
3883          fs_reg indirect = retype(get_nir_src(instr->src[0]),
3884                                   BRW_REGISTER_TYPE_UD);
3885 
3886          /* We need to pass a size to the MOV_INDIRECT but we don't want it to
3887           * go past the end of the uniform.  In order to keep the n'th
3888           * component from running past, we subtract off the size of all but
3889           * one component of the vector.
3890           */
3891          assert(instr->const_index[1] >=
3892                 instr->num_components * (int) type_sz(dest.type));
3893          unsigned read_size = instr->const_index[1] -
3894             (instr->num_components - 1) * type_sz(dest.type);
3895 
3896          bool supports_64bit_indirects =
3897             !devinfo->is_cherryview && !gen_device_info_is_9lp(devinfo);
3898 
3899          if (type_sz(dest.type) != 8 || supports_64bit_indirects) {
3900             for (unsigned j = 0; j < instr->num_components; j++) {
3901                bld.emit(SHADER_OPCODE_MOV_INDIRECT,
3902                         offset(dest, bld, j), offset(src, bld, j),
3903                         indirect, brw_imm_ud(read_size));
3904             }
3905          } else {
3906             const unsigned num_mov_indirects =
3907                type_sz(dest.type) / type_sz(BRW_REGISTER_TYPE_UD);
3908             /* We read a little bit less per MOV INDIRECT, as they are now
3909              * 32-bits ones instead of 64-bit. Fix read_size then.
3910              */
3911             const unsigned read_size_32bit = read_size -
3912                 (num_mov_indirects - 1) * type_sz(BRW_REGISTER_TYPE_UD);
3913             for (unsigned j = 0; j < instr->num_components; j++) {
3914                for (unsigned i = 0; i < num_mov_indirects; i++) {
3915                   bld.emit(SHADER_OPCODE_MOV_INDIRECT,
3916                            subscript(offset(dest, bld, j), BRW_REGISTER_TYPE_UD, i),
3917                            subscript(offset(src, bld, j), BRW_REGISTER_TYPE_UD, i),
3918                            indirect, brw_imm_ud(read_size_32bit));
3919                }
3920             }
3921          }
3922       }
3923       break;
3924    }
3925 
3926    case nir_intrinsic_load_ubo: {
3927       nir_const_value *const_index = nir_src_as_const_value(instr->src[0]);
3928       fs_reg surf_index;
3929 
3930       if (const_index) {
3931          const unsigned index = stage_prog_data->binding_table.ubo_start +
3932                                 const_index->u32[0];
3933          surf_index = brw_imm_ud(index);
3934          brw_mark_surface_used(prog_data, index);
3935       } else {
3936          /* The block index is not a constant. Evaluate the index expression
3937           * per-channel and add the base UBO index; we have to select a value
3938           * from any live channel.
3939           */
3940          surf_index = vgrf(glsl_type::uint_type);
3941          bld.ADD(surf_index, get_nir_src(instr->src[0]),
3942                  brw_imm_ud(stage_prog_data->binding_table.ubo_start));
3943          surf_index = bld.emit_uniformize(surf_index);
3944 
3945          /* Assume this may touch any UBO. It would be nice to provide
3946           * a tighter bound, but the array information is already lowered away.
3947           */
3948          brw_mark_surface_used(prog_data,
3949                                stage_prog_data->binding_table.ubo_start +
3950                                nir->info.num_ubos - 1);
3951       }
3952 
3953       nir_const_value *const_offset = nir_src_as_const_value(instr->src[1]);
3954       if (const_offset == NULL) {
3955          fs_reg base_offset = retype(get_nir_src(instr->src[1]),
3956                                      BRW_REGISTER_TYPE_UD);
3957 
3958          for (int i = 0; i < instr->num_components; i++)
3959             VARYING_PULL_CONSTANT_LOAD(bld, offset(dest, bld, i), surf_index,
3960                                        base_offset, i * type_sz(dest.type));
3961       } else {
3962          /* Even if we are loading doubles, a pull constant load will load
3963           * a 32-bit vec4, so should only reserve vgrf space for that. If we
3964           * need to load a full dvec4 we will have to emit 2 loads. This is
3965           * similar to demote_pull_constants(), except that in that case we
3966           * see individual accesses to each component of the vector and then
3967           * we let CSE deal with duplicate loads. Here we see a vector access
3968           * and we have to split it if necessary.
3969           */
3970          const unsigned type_size = type_sz(dest.type);
3971 
3972          /* See if we've selected this as a push constant candidate */
3973          if (const_index) {
3974             const unsigned ubo_block = const_index->u32[0];
3975             const unsigned offset_256b = const_offset->u32[0] / 32;
3976 
3977             fs_reg push_reg;
3978             for (int i = 0; i < 4; i++) {
3979                const struct brw_ubo_range *range = &prog_data->ubo_ranges[i];
3980                if (range->block == ubo_block &&
3981                    offset_256b >= range->start &&
3982                    offset_256b < range->start + range->length) {
3983 
3984                   push_reg = fs_reg(UNIFORM, UBO_START + i, dest.type);
3985                   push_reg.offset = const_offset->u32[0] - 32 * range->start;
3986                   break;
3987                }
3988             }
3989 
3990             if (push_reg.file != BAD_FILE) {
3991                for (unsigned i = 0; i < instr->num_components; i++) {
3992                   bld.MOV(offset(dest, bld, i),
3993                           byte_offset(push_reg, i * type_size));
3994                }
3995                break;
3996             }
3997          }
3998 
3999          const unsigned block_sz = 64; /* Fetch one cacheline at a time. */
4000          const fs_builder ubld = bld.exec_all().group(block_sz / 4, 0);
4001          const fs_reg packed_consts = ubld.vgrf(BRW_REGISTER_TYPE_UD);
4002 
4003          for (unsigned c = 0; c < instr->num_components;) {
4004             const unsigned base = const_offset->u32[0] + c * type_size;
4005             /* Number of usable components in the next block-aligned load. */
4006             const unsigned count = MIN2(instr->num_components - c,
4007                                         (block_sz - base % block_sz) / type_size);
4008 
4009             ubld.emit(FS_OPCODE_UNIFORM_PULL_CONSTANT_LOAD,
4010                       packed_consts, surf_index,
4011                       brw_imm_ud(base & ~(block_sz - 1)));
4012 
4013             const fs_reg consts =
4014                retype(byte_offset(packed_consts, base & (block_sz - 1)),
4015                       dest.type);
4016 
4017             for (unsigned d = 0; d < count; d++)
4018                bld.MOV(offset(dest, bld, c + d), component(consts, d));
4019 
4020             c += count;
4021          }
4022       }
4023       break;
4024    }
4025 
4026    case nir_intrinsic_load_ssbo: {
4027       assert(devinfo->gen >= 7);
4028 
4029       nir_const_value *const_uniform_block =
4030          nir_src_as_const_value(instr->src[0]);
4031 
4032       fs_reg surf_index;
4033       if (const_uniform_block) {
4034          unsigned index = stage_prog_data->binding_table.ssbo_start +
4035                           const_uniform_block->u32[0];
4036          surf_index = brw_imm_ud(index);
4037          brw_mark_surface_used(prog_data, index);
4038       } else {
4039          surf_index = vgrf(glsl_type::uint_type);
4040          bld.ADD(surf_index, get_nir_src(instr->src[0]),
4041                  brw_imm_ud(stage_prog_data->binding_table.ssbo_start));
4042 
4043          /* Assume this may touch any UBO. It would be nice to provide
4044           * a tighter bound, but the array information is already lowered away.
4045           */
4046          brw_mark_surface_used(prog_data,
4047                                stage_prog_data->binding_table.ssbo_start +
4048                                nir->info.num_ssbos - 1);
4049       }
4050 
4051       fs_reg offset_reg;
4052       nir_const_value *const_offset = nir_src_as_const_value(instr->src[1]);
4053       if (const_offset) {
4054          offset_reg = brw_imm_ud(const_offset->u32[0]);
4055       } else {
4056          offset_reg = get_nir_src(instr->src[1]);
4057       }
4058 
4059       /* Read the vector */
4060       do_untyped_vector_read(bld, dest, surf_index, offset_reg,
4061                              instr->num_components);
4062 
4063       break;
4064    }
4065 
4066    case nir_intrinsic_store_ssbo: {
4067       assert(devinfo->gen >= 7);
4068 
4069       if (stage == MESA_SHADER_FRAGMENT)
4070          brw_wm_prog_data(prog_data)->has_side_effects = true;
4071 
4072       /* Block index */
4073       fs_reg surf_index;
4074       nir_const_value *const_uniform_block =
4075          nir_src_as_const_value(instr->src[1]);
4076       if (const_uniform_block) {
4077          unsigned index = stage_prog_data->binding_table.ssbo_start +
4078                           const_uniform_block->u32[0];
4079          surf_index = brw_imm_ud(index);
4080          brw_mark_surface_used(prog_data, index);
4081       } else {
4082          surf_index = vgrf(glsl_type::uint_type);
4083          bld.ADD(surf_index, get_nir_src(instr->src[1]),
4084                   brw_imm_ud(stage_prog_data->binding_table.ssbo_start));
4085 
4086          brw_mark_surface_used(prog_data,
4087                                stage_prog_data->binding_table.ssbo_start +
4088                                nir->info.num_ssbos - 1);
4089       }
4090 
4091       /* Value */
4092       fs_reg val_reg = get_nir_src(instr->src[0]);
4093 
4094       /* Writemask */
4095       unsigned writemask = instr->const_index[0];
4096 
4097       /* get_nir_src() retypes to integer. Be wary of 64-bit types though
4098        * since the untyped writes below operate in units of 32-bits, which
4099        * means that we need to write twice as many components each time.
4100        * Also, we have to suffle 64-bit data to be in the appropriate layout
4101        * expected by our 32-bit write messages.
4102        */
4103       unsigned bit_size = nir_src_bit_size(instr->src[0]);
4104       unsigned type_size = bit_size / 8;
4105 
4106       /* Combine groups of consecutive enabled channels in one write
4107        * message. We use ffs to find the first enabled channel and then ffs on
4108        * the bit-inverse, down-shifted writemask to determine the num_components
4109        * of the block of enabled bits.
4110        */
4111       while (writemask) {
4112          unsigned first_component = ffs(writemask) - 1;
4113          unsigned num_components = ffs(~(writemask >> first_component)) - 1;
4114          fs_reg write_src = offset(val_reg, bld, first_component);
4115 
4116          if (type_size > 4) {
4117             /* We can't write more than 2 64-bit components at once. Limit
4118              * the num_components of the write to what we can do and let the next
4119              * iteration handle the rest.
4120              */
4121             num_components = MIN2(2, num_components);
4122             write_src = shuffle_64bit_data_for_32bit_write(bld, write_src,
4123                                                            num_components);
4124          } else if (type_size < 4) {
4125             assert(type_size == 2);
4126             /* For 16-bit types we pack two consecutive values into a 32-bit
4127              * word and use an untyped write message. For single values or not
4128              * 32-bit-aligned we need to use byte-scattered writes because
4129              * untyped writes works with 32-bit components with 32-bit
4130              * alignment. byte_scattered_write messages only support one
4131              * 16-bit component at a time.
4132              *
4133              * For example, if there is a 3-components vector we submit one
4134              * untyped-write message of 32-bit (first two components), and one
4135              * byte-scattered write message (the last component).
4136              */
4137 
4138             if (first_component % 2) {
4139                /* If we use a .yz writemask we also need to emit 2
4140                 * byte-scattered write messages because of y-component not
4141                 * being aligned to 32-bit.
4142                 */
4143                num_components = 1;
4144             } else if (num_components > 2 && (num_components % 2)) {
4145                /* If there is an odd number of consecutive components we left
4146                 * the not paired component for a following emit of length == 1
4147                 * with byte_scattered_write.
4148                 */
4149                num_components --;
4150             }
4151             /* For num_components == 1 we are also shuffling the component
4152              * because byte scattered writes of 16-bit need values to be dword
4153              * aligned. Shuffling only one component would be the same as
4154              * striding it.
4155              */
4156             fs_reg tmp = bld.vgrf(BRW_REGISTER_TYPE_D,
4157                                   DIV_ROUND_UP(num_components, 2));
4158             shuffle_16bit_data_for_32bit_write(bld, tmp, write_src,
4159                                                num_components);
4160             write_src = tmp;
4161          }
4162 
4163          fs_reg offset_reg;
4164          nir_const_value *const_offset = nir_src_as_const_value(instr->src[2]);
4165          if (const_offset) {
4166             offset_reg = brw_imm_ud(const_offset->u32[0] +
4167                                     type_size * first_component);
4168          } else {
4169             offset_reg = vgrf(glsl_type::uint_type);
4170             bld.ADD(offset_reg,
4171                     retype(get_nir_src(instr->src[2]), BRW_REGISTER_TYPE_UD),
4172                     brw_imm_ud(type_size * first_component));
4173          }
4174 
4175          if (type_size < 4 && num_components == 1) {
4176             assert(type_size == 2);
4177             /* Untyped Surface messages have a fixed 32-bit size, so we need
4178              * to rely on byte scattered in order to write 16-bit elements.
4179              * The byte_scattered_write message needs that every written 16-bit
4180              * type to be aligned 32-bits (stride=2).
4181              * Additionally, while on Untyped Surface messages the
4182              * bits of the execution mask are ANDed with the corresponding
4183              * bits of the Pixel/Sample Mask, that is not the case for byte
4184              * scattered writes. That is needed to avoid ssbo stores writing
4185              * on helper invocations. So when that can affect, we load the
4186              * sample mask, and predicate the send message.
4187              */
4188             brw_predicate pred = BRW_PREDICATE_NONE;
4189 
4190             if (stage == MESA_SHADER_FRAGMENT) {
4191                bld.emit(FS_OPCODE_MOV_DISPATCH_TO_FLAGS);
4192                pred = BRW_PREDICATE_NORMAL;
4193             }
4194 
4195             emit_byte_scattered_write(bld, surf_index, offset_reg,
4196                                       write_src,
4197                                       1 /* dims */, 1,
4198                                       bit_size,
4199                                       pred);
4200          } else {
4201             assert(num_components * type_size <= 16);
4202             assert((num_components * type_size) % 4 == 0);
4203             assert((first_component * type_size) % 4 == 0);
4204             unsigned num_slots = (num_components * type_size) / 4;
4205 
4206             emit_untyped_write(bld, surf_index, offset_reg,
4207                                write_src,
4208                                1 /* dims */, num_slots,
4209                                BRW_PREDICATE_NONE);
4210          }
4211 
4212          /* Clear the bits in the writemask that we just wrote, then try
4213           * again to see if more channels are left.
4214           */
4215          writemask &= (15 << (first_component + num_components));
4216       }
4217       break;
4218    }
4219 
4220    case nir_intrinsic_store_output: {
4221       fs_reg src = get_nir_src(instr->src[0]);
4222 
4223       nir_const_value *const_offset = nir_src_as_const_value(instr->src[1]);
4224       assert(const_offset && "Indirect output stores not allowed");
4225 
4226       unsigned num_components = instr->num_components;
4227       unsigned first_component = nir_intrinsic_component(instr);
4228       if (nir_src_bit_size(instr->src[0]) == 64) {
4229          src = shuffle_64bit_data_for_32bit_write(bld, src, num_components);
4230          num_components *= 2;
4231       }
4232 
4233       fs_reg new_dest = retype(offset(outputs[instr->const_index[0]], bld,
4234                                       4 * const_offset->u32[0]), src.type);
4235       for (unsigned j = 0; j < num_components; j++) {
4236          bld.MOV(offset(new_dest, bld, j + first_component),
4237                  offset(src, bld, j));
4238       }
4239       break;
4240    }
4241 
4242    case nir_intrinsic_ssbo_atomic_add:
4243       nir_emit_ssbo_atomic(bld, BRW_AOP_ADD, instr);
4244       break;
4245    case nir_intrinsic_ssbo_atomic_imin:
4246       nir_emit_ssbo_atomic(bld, BRW_AOP_IMIN, instr);
4247       break;
4248    case nir_intrinsic_ssbo_atomic_umin:
4249       nir_emit_ssbo_atomic(bld, BRW_AOP_UMIN, instr);
4250       break;
4251    case nir_intrinsic_ssbo_atomic_imax:
4252       nir_emit_ssbo_atomic(bld, BRW_AOP_IMAX, instr);
4253       break;
4254    case nir_intrinsic_ssbo_atomic_umax:
4255       nir_emit_ssbo_atomic(bld, BRW_AOP_UMAX, instr);
4256       break;
4257    case nir_intrinsic_ssbo_atomic_and:
4258       nir_emit_ssbo_atomic(bld, BRW_AOP_AND, instr);
4259       break;
4260    case nir_intrinsic_ssbo_atomic_or:
4261       nir_emit_ssbo_atomic(bld, BRW_AOP_OR, instr);
4262       break;
4263    case nir_intrinsic_ssbo_atomic_xor:
4264       nir_emit_ssbo_atomic(bld, BRW_AOP_XOR, instr);
4265       break;
4266    case nir_intrinsic_ssbo_atomic_exchange:
4267       nir_emit_ssbo_atomic(bld, BRW_AOP_MOV, instr);
4268       break;
4269    case nir_intrinsic_ssbo_atomic_comp_swap:
4270       nir_emit_ssbo_atomic(bld, BRW_AOP_CMPWR, instr);
4271       break;
4272 
4273    case nir_intrinsic_get_buffer_size: {
4274       nir_const_value *const_uniform_block = nir_src_as_const_value(instr->src[0]);
4275       unsigned ssbo_index = const_uniform_block ? const_uniform_block->u32[0] : 0;
4276 
4277       /* A resinfo's sampler message is used to get the buffer size.  The
4278        * SIMD8's writeback message consists of four registers and SIMD16's
4279        * writeback message consists of 8 destination registers (two per each
4280        * component).  Because we are only interested on the first channel of
4281        * the first returned component, where resinfo returns the buffer size
4282        * for SURFTYPE_BUFFER, we can just use the SIMD8 variant regardless of
4283        * the dispatch width.
4284        */
4285       const fs_builder ubld = bld.exec_all().group(8, 0);
4286       fs_reg src_payload = ubld.vgrf(BRW_REGISTER_TYPE_UD);
4287       fs_reg ret_payload = ubld.vgrf(BRW_REGISTER_TYPE_UD, 4);
4288 
4289       /* Set LOD = 0 */
4290       ubld.MOV(src_payload, brw_imm_d(0));
4291 
4292       const unsigned index = prog_data->binding_table.ssbo_start + ssbo_index;
4293       fs_inst *inst = ubld.emit(SHADER_OPCODE_GET_BUFFER_SIZE, ret_payload,
4294                                 src_payload, brw_imm_ud(index));
4295       inst->header_size = 0;
4296       inst->mlen = 1;
4297       inst->size_written = 4 * REG_SIZE;
4298 
4299       bld.MOV(retype(dest, ret_payload.type), component(ret_payload, 0));
4300       brw_mark_surface_used(prog_data, index);
4301       break;
4302    }
4303 
4304    case nir_intrinsic_load_subgroup_invocation:
4305       bld.MOV(retype(dest, BRW_REGISTER_TYPE_D),
4306               nir_system_values[SYSTEM_VALUE_SUBGROUP_INVOCATION]);
4307       break;
4308 
4309    case nir_intrinsic_load_subgroup_eq_mask:
4310    case nir_intrinsic_load_subgroup_ge_mask:
4311    case nir_intrinsic_load_subgroup_gt_mask:
4312    case nir_intrinsic_load_subgroup_le_mask:
4313    case nir_intrinsic_load_subgroup_lt_mask:
4314       unreachable("not reached");
4315 
4316    case nir_intrinsic_vote_any: {
4317       const fs_builder ubld = bld.exec_all().group(1, 0);
4318 
4319       /* The any/all predicates do not consider channel enables. To prevent
4320        * dead channels from affecting the result, we initialize the flag with
4321        * with the identity value for the logical operation.
4322        */
4323       if (dispatch_width == 32) {
4324          /* For SIMD32, we use a UD type so we fill both f0.0 and f0.1. */
4325          ubld.MOV(retype(brw_flag_reg(0, 0), BRW_REGISTER_TYPE_UD),
4326                          brw_imm_ud(0));
4327       } else {
4328          ubld.MOV(brw_flag_reg(0, 0), brw_imm_uw(0));
4329       }
4330       bld.CMP(bld.null_reg_d(), get_nir_src(instr->src[0]), brw_imm_d(0), BRW_CONDITIONAL_NZ);
4331 
4332       /* For some reason, the any/all predicates don't work properly with
4333        * SIMD32.  In particular, it appears that a SEL with a QtrCtrl of 2H
4334        * doesn't read the correct subset of the flag register and you end up
4335        * getting garbage in the second half.  Work around this by using a pair
4336        * of 1-wide MOVs and scattering the result.
4337        */
4338       fs_reg res1 = ubld.vgrf(BRW_REGISTER_TYPE_D);
4339       ubld.MOV(res1, brw_imm_d(0));
4340       set_predicate(dispatch_width == 8  ? BRW_PREDICATE_ALIGN1_ANY8H :
4341                     dispatch_width == 16 ? BRW_PREDICATE_ALIGN1_ANY16H :
4342                                            BRW_PREDICATE_ALIGN1_ANY32H,
4343                     ubld.MOV(res1, brw_imm_d(-1)));
4344 
4345       bld.MOV(retype(dest, BRW_REGISTER_TYPE_D), component(res1, 0));
4346       break;
4347    }
4348    case nir_intrinsic_vote_all: {
4349       const fs_builder ubld = bld.exec_all().group(1, 0);
4350 
4351       /* The any/all predicates do not consider channel enables. To prevent
4352        * dead channels from affecting the result, we initialize the flag with
4353        * with the identity value for the logical operation.
4354        */
4355       if (dispatch_width == 32) {
4356          /* For SIMD32, we use a UD type so we fill both f0.0 and f0.1. */
4357          ubld.MOV(retype(brw_flag_reg(0, 0), BRW_REGISTER_TYPE_UD),
4358                          brw_imm_ud(0xffffffff));
4359       } else {
4360          ubld.MOV(brw_flag_reg(0, 0), brw_imm_uw(0xffff));
4361       }
4362       bld.CMP(bld.null_reg_d(), get_nir_src(instr->src[0]), brw_imm_d(0), BRW_CONDITIONAL_NZ);
4363 
4364       /* For some reason, the any/all predicates don't work properly with
4365        * SIMD32.  In particular, it appears that a SEL with a QtrCtrl of 2H
4366        * doesn't read the correct subset of the flag register and you end up
4367        * getting garbage in the second half.  Work around this by using a pair
4368        * of 1-wide MOVs and scattering the result.
4369        */
4370       fs_reg res1 = ubld.vgrf(BRW_REGISTER_TYPE_D);
4371       ubld.MOV(res1, brw_imm_d(0));
4372       set_predicate(dispatch_width == 8  ? BRW_PREDICATE_ALIGN1_ALL8H :
4373                     dispatch_width == 16 ? BRW_PREDICATE_ALIGN1_ALL16H :
4374                                            BRW_PREDICATE_ALIGN1_ALL32H,
4375                     ubld.MOV(res1, brw_imm_d(-1)));
4376 
4377       bld.MOV(retype(dest, BRW_REGISTER_TYPE_D), component(res1, 0));
4378       break;
4379    }
4380    case nir_intrinsic_vote_eq: {
4381       fs_reg value = get_nir_src(instr->src[0]);
4382       fs_reg uniformized = bld.emit_uniformize(value);
4383       const fs_builder ubld = bld.exec_all().group(1, 0);
4384 
4385       /* The any/all predicates do not consider channel enables. To prevent
4386        * dead channels from affecting the result, we initialize the flag with
4387        * with the identity value for the logical operation.
4388        */
4389       if (dispatch_width == 32) {
4390          /* For SIMD32, we use a UD type so we fill both f0.0 and f0.1. */
4391          ubld.MOV(retype(brw_flag_reg(0, 0), BRW_REGISTER_TYPE_UD),
4392                          brw_imm_ud(0xffffffff));
4393       } else {
4394          ubld.MOV(brw_flag_reg(0, 0), brw_imm_uw(0xffff));
4395       }
4396       bld.CMP(bld.null_reg_d(), value, uniformized, BRW_CONDITIONAL_Z);
4397 
4398       /* For some reason, the any/all predicates don't work properly with
4399        * SIMD32.  In particular, it appears that a SEL with a QtrCtrl of 2H
4400        * doesn't read the correct subset of the flag register and you end up
4401        * getting garbage in the second half.  Work around this by using a pair
4402        * of 1-wide MOVs and scattering the result.
4403        */
4404       fs_reg res1 = ubld.vgrf(BRW_REGISTER_TYPE_D);
4405       ubld.MOV(res1, brw_imm_d(0));
4406       set_predicate(dispatch_width == 8  ? BRW_PREDICATE_ALIGN1_ALL8H :
4407                     dispatch_width == 16 ? BRW_PREDICATE_ALIGN1_ALL16H :
4408                                            BRW_PREDICATE_ALIGN1_ALL32H,
4409                     ubld.MOV(res1, brw_imm_d(-1)));
4410 
4411       bld.MOV(retype(dest, BRW_REGISTER_TYPE_D), component(res1, 0));
4412       break;
4413    }
4414 
4415    case nir_intrinsic_ballot: {
4416       const fs_reg value = retype(get_nir_src(instr->src[0]),
4417                                   BRW_REGISTER_TYPE_UD);
4418       struct brw_reg flag = brw_flag_reg(0, 0);
4419       /* FIXME: For SIMD32 programs, this causes us to stomp on f0.1 as well
4420        * as f0.0.  This is a problem for fragment programs as we currently use
4421        * f0.1 for discards.  Fortunately, we don't support SIMD32 fragment
4422        * programs yet so this isn't a problem.  When we do, something will
4423        * have to change.
4424        */
4425       if (dispatch_width == 32)
4426          flag.type = BRW_REGISTER_TYPE_UD;
4427 
4428       bld.exec_all().group(1, 0).MOV(flag, brw_imm_ud(0u));
4429       bld.CMP(bld.null_reg_ud(), value, brw_imm_ud(0u), BRW_CONDITIONAL_NZ);
4430 
4431       if (instr->dest.ssa.bit_size > 32) {
4432          dest.type = BRW_REGISTER_TYPE_UQ;
4433       } else {
4434          dest.type = BRW_REGISTER_TYPE_UD;
4435       }
4436       bld.MOV(dest, flag);
4437       break;
4438    }
4439 
4440    case nir_intrinsic_read_invocation: {
4441       const fs_reg value = get_nir_src(instr->src[0]);
4442       const fs_reg invocation = get_nir_src(instr->src[1]);
4443       fs_reg tmp = bld.vgrf(value.type);
4444 
4445       bld.exec_all().emit(SHADER_OPCODE_BROADCAST, tmp, value,
4446                           bld.emit_uniformize(invocation));
4447 
4448       bld.MOV(retype(dest, value.type), fs_reg(component(tmp, 0)));
4449       break;
4450    }
4451 
4452    case nir_intrinsic_read_first_invocation: {
4453       const fs_reg value = get_nir_src(instr->src[0]);
4454       bld.MOV(retype(dest, value.type), bld.emit_uniformize(value));
4455       break;
4456    }
4457 
4458    default:
4459       unreachable("unknown intrinsic");
4460    }
4461 }
4462 
4463 void
nir_emit_ssbo_atomic(const fs_builder & bld,int op,nir_intrinsic_instr * instr)4464 fs_visitor::nir_emit_ssbo_atomic(const fs_builder &bld,
4465                                  int op, nir_intrinsic_instr *instr)
4466 {
4467    if (stage == MESA_SHADER_FRAGMENT)
4468       brw_wm_prog_data(prog_data)->has_side_effects = true;
4469 
4470    fs_reg dest;
4471    if (nir_intrinsic_infos[instr->intrinsic].has_dest)
4472       dest = get_nir_dest(instr->dest);
4473 
4474    fs_reg surface;
4475    nir_const_value *const_surface = nir_src_as_const_value(instr->src[0]);
4476    if (const_surface) {
4477       unsigned surf_index = stage_prog_data->binding_table.ssbo_start +
4478                             const_surface->u32[0];
4479       surface = brw_imm_ud(surf_index);
4480       brw_mark_surface_used(prog_data, surf_index);
4481    } else {
4482       surface = vgrf(glsl_type::uint_type);
4483       bld.ADD(surface, get_nir_src(instr->src[0]),
4484               brw_imm_ud(stage_prog_data->binding_table.ssbo_start));
4485 
4486       /* Assume this may touch any SSBO. This is the same we do for other
4487        * UBO/SSBO accesses with non-constant surface.
4488        */
4489       brw_mark_surface_used(prog_data,
4490                             stage_prog_data->binding_table.ssbo_start +
4491                             nir->info.num_ssbos - 1);
4492    }
4493 
4494    fs_reg offset = get_nir_src(instr->src[1]);
4495    fs_reg data1 = get_nir_src(instr->src[2]);
4496    fs_reg data2;
4497    if (op == BRW_AOP_CMPWR)
4498       data2 = get_nir_src(instr->src[3]);
4499 
4500    /* Emit the actual atomic operation */
4501 
4502    fs_reg atomic_result = emit_untyped_atomic(bld, surface, offset,
4503                                               data1, data2,
4504                                               1 /* dims */, 1 /* rsize */,
4505                                               op,
4506                                               BRW_PREDICATE_NONE);
4507    dest.type = atomic_result.type;
4508    bld.MOV(dest, atomic_result);
4509 }
4510 
4511 void
nir_emit_shared_atomic(const fs_builder & bld,int op,nir_intrinsic_instr * instr)4512 fs_visitor::nir_emit_shared_atomic(const fs_builder &bld,
4513                                    int op, nir_intrinsic_instr *instr)
4514 {
4515    fs_reg dest;
4516    if (nir_intrinsic_infos[instr->intrinsic].has_dest)
4517       dest = get_nir_dest(instr->dest);
4518 
4519    fs_reg surface = brw_imm_ud(GEN7_BTI_SLM);
4520    fs_reg offset;
4521    fs_reg data1 = get_nir_src(instr->src[1]);
4522    fs_reg data2;
4523    if (op == BRW_AOP_CMPWR)
4524       data2 = get_nir_src(instr->src[2]);
4525 
4526    /* Get the offset */
4527    nir_const_value *const_offset = nir_src_as_const_value(instr->src[0]);
4528    if (const_offset) {
4529       offset = brw_imm_ud(instr->const_index[0] + const_offset->u32[0]);
4530    } else {
4531       offset = vgrf(glsl_type::uint_type);
4532       bld.ADD(offset,
4533 	      retype(get_nir_src(instr->src[0]), BRW_REGISTER_TYPE_UD),
4534 	      brw_imm_ud(instr->const_index[0]));
4535    }
4536 
4537    /* Emit the actual atomic operation operation */
4538 
4539    fs_reg atomic_result = emit_untyped_atomic(bld, surface, offset,
4540                                               data1, data2,
4541                                               1 /* dims */, 1 /* rsize */,
4542                                               op,
4543                                               BRW_PREDICATE_NONE);
4544    dest.type = atomic_result.type;
4545    bld.MOV(dest, atomic_result);
4546 }
4547 
4548 void
nir_emit_texture(const fs_builder & bld,nir_tex_instr * instr)4549 fs_visitor::nir_emit_texture(const fs_builder &bld, nir_tex_instr *instr)
4550 {
4551    unsigned texture = instr->texture_index;
4552    unsigned sampler = instr->sampler_index;
4553 
4554    fs_reg srcs[TEX_LOGICAL_NUM_SRCS];
4555 
4556    srcs[TEX_LOGICAL_SRC_SURFACE] = brw_imm_ud(texture);
4557    srcs[TEX_LOGICAL_SRC_SAMPLER] = brw_imm_ud(sampler);
4558 
4559    int lod_components = 0;
4560 
4561    /* The hardware requires a LOD for buffer textures */
4562    if (instr->sampler_dim == GLSL_SAMPLER_DIM_BUF)
4563       srcs[TEX_LOGICAL_SRC_LOD] = brw_imm_d(0);
4564 
4565    uint32_t header_bits = 0;
4566    for (unsigned i = 0; i < instr->num_srcs; i++) {
4567       fs_reg src = get_nir_src(instr->src[i].src);
4568       switch (instr->src[i].src_type) {
4569       case nir_tex_src_bias:
4570          srcs[TEX_LOGICAL_SRC_LOD] =
4571             retype(get_nir_src_imm(instr->src[i].src), BRW_REGISTER_TYPE_F);
4572          break;
4573       case nir_tex_src_comparator:
4574          srcs[TEX_LOGICAL_SRC_SHADOW_C] = retype(src, BRW_REGISTER_TYPE_F);
4575          break;
4576       case nir_tex_src_coord:
4577          switch (instr->op) {
4578          case nir_texop_txf:
4579          case nir_texop_txf_ms:
4580          case nir_texop_txf_ms_mcs:
4581          case nir_texop_samples_identical:
4582             srcs[TEX_LOGICAL_SRC_COORDINATE] = retype(src, BRW_REGISTER_TYPE_D);
4583             break;
4584          default:
4585             srcs[TEX_LOGICAL_SRC_COORDINATE] = retype(src, BRW_REGISTER_TYPE_F);
4586             break;
4587          }
4588          break;
4589       case nir_tex_src_ddx:
4590          srcs[TEX_LOGICAL_SRC_LOD] = retype(src, BRW_REGISTER_TYPE_F);
4591          lod_components = nir_tex_instr_src_size(instr, i);
4592          break;
4593       case nir_tex_src_ddy:
4594          srcs[TEX_LOGICAL_SRC_LOD2] = retype(src, BRW_REGISTER_TYPE_F);
4595          break;
4596       case nir_tex_src_lod:
4597          switch (instr->op) {
4598          case nir_texop_txs:
4599             srcs[TEX_LOGICAL_SRC_LOD] =
4600                retype(get_nir_src_imm(instr->src[i].src), BRW_REGISTER_TYPE_UD);
4601             break;
4602          case nir_texop_txf:
4603             srcs[TEX_LOGICAL_SRC_LOD] =
4604                retype(get_nir_src_imm(instr->src[i].src), BRW_REGISTER_TYPE_D);
4605             break;
4606          default:
4607             srcs[TEX_LOGICAL_SRC_LOD] =
4608                retype(get_nir_src_imm(instr->src[i].src), BRW_REGISTER_TYPE_F);
4609             break;
4610          }
4611          break;
4612       case nir_tex_src_ms_index:
4613          srcs[TEX_LOGICAL_SRC_SAMPLE_INDEX] = retype(src, BRW_REGISTER_TYPE_UD);
4614          break;
4615 
4616       case nir_tex_src_offset: {
4617          nir_const_value *const_offset =
4618             nir_src_as_const_value(instr->src[i].src);
4619          unsigned offset_bits = 0;
4620          if (const_offset &&
4621              brw_texture_offset(const_offset->i32,
4622                                 nir_tex_instr_src_size(instr, i),
4623                                 &offset_bits)) {
4624             header_bits |= offset_bits;
4625          } else {
4626             srcs[TEX_LOGICAL_SRC_TG4_OFFSET] =
4627                retype(src, BRW_REGISTER_TYPE_D);
4628          }
4629          break;
4630       }
4631 
4632       case nir_tex_src_projector:
4633          unreachable("should be lowered");
4634 
4635       case nir_tex_src_texture_offset: {
4636          /* Figure out the highest possible texture index and mark it as used */
4637          uint32_t max_used = texture + instr->texture_array_size - 1;
4638          if (instr->op == nir_texop_tg4 && devinfo->gen < 8) {
4639             max_used += stage_prog_data->binding_table.gather_texture_start;
4640          } else {
4641             max_used += stage_prog_data->binding_table.texture_start;
4642          }
4643          brw_mark_surface_used(prog_data, max_used);
4644 
4645          /* Emit code to evaluate the actual indexing expression */
4646          fs_reg tmp = vgrf(glsl_type::uint_type);
4647          bld.ADD(tmp, src, brw_imm_ud(texture));
4648          srcs[TEX_LOGICAL_SRC_SURFACE] = bld.emit_uniformize(tmp);
4649          break;
4650       }
4651 
4652       case nir_tex_src_sampler_offset: {
4653          /* Emit code to evaluate the actual indexing expression */
4654          fs_reg tmp = vgrf(glsl_type::uint_type);
4655          bld.ADD(tmp, src, brw_imm_ud(sampler));
4656          srcs[TEX_LOGICAL_SRC_SAMPLER] = bld.emit_uniformize(tmp);
4657          break;
4658       }
4659 
4660       case nir_tex_src_ms_mcs:
4661          assert(instr->op == nir_texop_txf_ms);
4662          srcs[TEX_LOGICAL_SRC_MCS] = retype(src, BRW_REGISTER_TYPE_D);
4663          break;
4664 
4665       case nir_tex_src_plane: {
4666          nir_const_value *const_plane =
4667             nir_src_as_const_value(instr->src[i].src);
4668          const uint32_t plane = const_plane->u32[0];
4669          const uint32_t texture_index =
4670             instr->texture_index +
4671             stage_prog_data->binding_table.plane_start[plane] -
4672             stage_prog_data->binding_table.texture_start;
4673 
4674          srcs[TEX_LOGICAL_SRC_SURFACE] = brw_imm_ud(texture_index);
4675          break;
4676       }
4677 
4678       default:
4679          unreachable("unknown texture source");
4680       }
4681    }
4682 
4683    if (srcs[TEX_LOGICAL_SRC_MCS].file == BAD_FILE &&
4684        (instr->op == nir_texop_txf_ms ||
4685         instr->op == nir_texop_samples_identical)) {
4686       if (devinfo->gen >= 7 &&
4687           key_tex->compressed_multisample_layout_mask & (1 << texture)) {
4688          srcs[TEX_LOGICAL_SRC_MCS] =
4689             emit_mcs_fetch(srcs[TEX_LOGICAL_SRC_COORDINATE],
4690                            instr->coord_components,
4691                            srcs[TEX_LOGICAL_SRC_SURFACE]);
4692       } else {
4693          srcs[TEX_LOGICAL_SRC_MCS] = brw_imm_ud(0u);
4694       }
4695    }
4696 
4697    srcs[TEX_LOGICAL_SRC_COORD_COMPONENTS] = brw_imm_d(instr->coord_components);
4698    srcs[TEX_LOGICAL_SRC_GRAD_COMPONENTS] = brw_imm_d(lod_components);
4699 
4700    enum opcode opcode;
4701    switch (instr->op) {
4702    case nir_texop_tex:
4703       opcode = (stage == MESA_SHADER_FRAGMENT ? SHADER_OPCODE_TEX_LOGICAL :
4704                 SHADER_OPCODE_TXL_LOGICAL);
4705       break;
4706    case nir_texop_txb:
4707       opcode = FS_OPCODE_TXB_LOGICAL;
4708       break;
4709    case nir_texop_txl:
4710       opcode = SHADER_OPCODE_TXL_LOGICAL;
4711       break;
4712    case nir_texop_txd:
4713       opcode = SHADER_OPCODE_TXD_LOGICAL;
4714       break;
4715    case nir_texop_txf:
4716       opcode = SHADER_OPCODE_TXF_LOGICAL;
4717       break;
4718    case nir_texop_txf_ms:
4719       if ((key_tex->msaa_16 & (1 << sampler)))
4720          opcode = SHADER_OPCODE_TXF_CMS_W_LOGICAL;
4721       else
4722          opcode = SHADER_OPCODE_TXF_CMS_LOGICAL;
4723       break;
4724    case nir_texop_txf_ms_mcs:
4725       opcode = SHADER_OPCODE_TXF_MCS_LOGICAL;
4726       break;
4727    case nir_texop_query_levels:
4728    case nir_texop_txs:
4729       opcode = SHADER_OPCODE_TXS_LOGICAL;
4730       break;
4731    case nir_texop_lod:
4732       opcode = SHADER_OPCODE_LOD_LOGICAL;
4733       break;
4734    case nir_texop_tg4:
4735       if (srcs[TEX_LOGICAL_SRC_TG4_OFFSET].file != BAD_FILE)
4736          opcode = SHADER_OPCODE_TG4_OFFSET_LOGICAL;
4737       else
4738          opcode = SHADER_OPCODE_TG4_LOGICAL;
4739       break;
4740    case nir_texop_texture_samples:
4741       opcode = SHADER_OPCODE_SAMPLEINFO_LOGICAL;
4742       break;
4743    case nir_texop_samples_identical: {
4744       fs_reg dst = retype(get_nir_dest(instr->dest), BRW_REGISTER_TYPE_D);
4745 
4746       /* If mcs is an immediate value, it means there is no MCS.  In that case
4747        * just return false.
4748        */
4749       if (srcs[TEX_LOGICAL_SRC_MCS].file == BRW_IMMEDIATE_VALUE) {
4750          bld.MOV(dst, brw_imm_ud(0u));
4751       } else if ((key_tex->msaa_16 & (1 << sampler))) {
4752          fs_reg tmp = vgrf(glsl_type::uint_type);
4753          bld.OR(tmp, srcs[TEX_LOGICAL_SRC_MCS],
4754                 offset(srcs[TEX_LOGICAL_SRC_MCS], bld, 1));
4755          bld.CMP(dst, tmp, brw_imm_ud(0u), BRW_CONDITIONAL_EQ);
4756       } else {
4757          bld.CMP(dst, srcs[TEX_LOGICAL_SRC_MCS], brw_imm_ud(0u),
4758                  BRW_CONDITIONAL_EQ);
4759       }
4760       return;
4761    }
4762    default:
4763       unreachable("unknown texture opcode");
4764    }
4765 
4766    if (instr->op == nir_texop_tg4) {
4767       if (instr->component == 1 &&
4768           key_tex->gather_channel_quirk_mask & (1 << texture)) {
4769          /* gather4 sampler is broken for green channel on RG32F --
4770           * we must ask for blue instead.
4771           */
4772          header_bits |= 2 << 16;
4773       } else {
4774          header_bits |= instr->component << 16;
4775       }
4776    }
4777 
4778    fs_reg dst = bld.vgrf(brw_type_for_nir_type(devinfo, instr->dest_type), 4);
4779    fs_inst *inst = bld.emit(opcode, dst, srcs, ARRAY_SIZE(srcs));
4780    inst->offset = header_bits;
4781 
4782    const unsigned dest_size = nir_tex_instr_dest_size(instr);
4783    if (devinfo->gen >= 9 &&
4784        instr->op != nir_texop_tg4 && instr->op != nir_texop_query_levels) {
4785       unsigned write_mask = instr->dest.is_ssa ?
4786                             nir_ssa_def_components_read(&instr->dest.ssa):
4787                             (1 << dest_size) - 1;
4788       assert(write_mask != 0); /* dead code should have been eliminated */
4789       inst->size_written = util_last_bit(write_mask) *
4790                            inst->dst.component_size(inst->exec_size);
4791    } else {
4792       inst->size_written = 4 * inst->dst.component_size(inst->exec_size);
4793    }
4794 
4795    if (srcs[TEX_LOGICAL_SRC_SHADOW_C].file != BAD_FILE)
4796       inst->shadow_compare = true;
4797 
4798    if (instr->op == nir_texop_tg4 && devinfo->gen == 6)
4799       emit_gen6_gather_wa(key_tex->gen6_gather_wa[texture], dst);
4800 
4801    fs_reg nir_dest[4];
4802    for (unsigned i = 0; i < dest_size; i++)
4803       nir_dest[i] = offset(dst, bld, i);
4804 
4805    if (instr->op == nir_texop_query_levels) {
4806       /* # levels is in .w */
4807       nir_dest[0] = offset(dst, bld, 3);
4808    } else if (instr->op == nir_texop_txs &&
4809               dest_size >= 3 && devinfo->gen < 7) {
4810       /* Gen4-6 return 0 instead of 1 for single layer surfaces. */
4811       fs_reg depth = offset(dst, bld, 2);
4812       nir_dest[2] = vgrf(glsl_type::int_type);
4813       bld.emit_minmax(nir_dest[2], depth, brw_imm_d(1), BRW_CONDITIONAL_GE);
4814    }
4815 
4816    bld.LOAD_PAYLOAD(get_nir_dest(instr->dest), nir_dest, dest_size, 0);
4817 }
4818 
4819 void
nir_emit_jump(const fs_builder & bld,nir_jump_instr * instr)4820 fs_visitor::nir_emit_jump(const fs_builder &bld, nir_jump_instr *instr)
4821 {
4822    switch (instr->type) {
4823    case nir_jump_break:
4824       bld.emit(BRW_OPCODE_BREAK);
4825       break;
4826    case nir_jump_continue:
4827       bld.emit(BRW_OPCODE_CONTINUE);
4828       break;
4829    case nir_jump_return:
4830    default:
4831       unreachable("unknown jump");
4832    }
4833 }
4834 
4835 /**
4836  * This helper takes the result of a load operation that reads 32-bit elements
4837  * in this format:
4838  *
4839  * x x x x x x x x
4840  * y y y y y y y y
4841  * z z z z z z z z
4842  * w w w w w w w w
4843  *
4844  * and shuffles the data to get this:
4845  *
4846  * x y x y x y x y
4847  * x y x y x y x y
4848  * z w z w z w z w
4849  * z w z w z w z w
4850  *
4851  * Which is exactly what we want if the load is reading 64-bit components
4852  * like doubles, where x represents the low 32-bit of the x double component
4853  * and y represents the high 32-bit of the x double component (likewise with
4854  * z and w for double component y). The parameter @components represents
4855  * the number of 64-bit components present in @src. This would typically be
4856  * 2 at most, since we can only fit 2 double elements in the result of a
4857  * vec4 load.
4858  *
4859  * Notice that @dst and @src can be the same register.
4860  */
4861 void
shuffle_32bit_load_result_to_64bit_data(const fs_builder & bld,const fs_reg & dst,const fs_reg & src,uint32_t components)4862 shuffle_32bit_load_result_to_64bit_data(const fs_builder &bld,
4863                                         const fs_reg &dst,
4864                                         const fs_reg &src,
4865                                         uint32_t components)
4866 {
4867    assert(type_sz(src.type) == 4);
4868    assert(type_sz(dst.type) == 8);
4869 
4870    /* A temporary that we will use to shuffle the 32-bit data of each
4871     * component in the vector into valid 64-bit data. We can't write directly
4872     * to dst because dst can be (and would usually be) the same as src
4873     * and in that case the first MOV in the loop below would overwrite the
4874     * data read in the second MOV.
4875     */
4876    fs_reg tmp = bld.vgrf(dst.type);
4877 
4878    for (unsigned i = 0; i < components; i++) {
4879       const fs_reg component_i = offset(src, bld, 2 * i);
4880 
4881       bld.MOV(subscript(tmp, src.type, 0), component_i);
4882       bld.MOV(subscript(tmp, src.type, 1), offset(component_i, bld, 1));
4883 
4884       bld.MOV(offset(dst, bld, i), tmp);
4885    }
4886 }
4887 
4888 void
shuffle_32bit_load_result_to_16bit_data(const fs_builder & bld,const fs_reg & dst,const fs_reg & src,uint32_t components)4889 shuffle_32bit_load_result_to_16bit_data(const fs_builder &bld,
4890                                         const fs_reg &dst,
4891                                         const fs_reg &src,
4892                                         uint32_t components)
4893 {
4894    assert(type_sz(src.type) == 4);
4895    assert(type_sz(dst.type) == 2);
4896 
4897    /* A temporary is used to un-shuffle the 32-bit data of each component in
4898     * into a valid 16-bit vector. We can't write directly to dst because it
4899     * can be the same register as src and in that case the first MOV in the
4900     * loop below would overwrite the data read in the second MOV.
4901     */
4902    fs_reg tmp = retype(bld.vgrf(src.type), dst.type);
4903 
4904    for (unsigned i = 0; i < components; i++) {
4905       const fs_reg component_i =
4906          subscript(offset(src, bld, i / 2), dst.type, i % 2);
4907 
4908       bld.MOV(offset(tmp, bld, i % 2), component_i);
4909 
4910       if (i % 2) {
4911          bld.MOV(offset(dst, bld, i -1), offset(tmp, bld, 0));
4912          bld.MOV(offset(dst, bld, i), offset(tmp, bld, 1));
4913       }
4914    }
4915    if (components % 2) {
4916       bld.MOV(offset(dst, bld, components - 1), tmp);
4917    }
4918 }
4919 
4920 /**
4921  * This helper does the inverse operation of
4922  * SHUFFLE_32BIT_LOAD_RESULT_TO_64BIT_DATA.
4923  *
4924  * We need to do this when we are going to use untyped write messsages that
4925  * operate with 32-bit components in order to arrange our 64-bit data to be
4926  * in the expected layout.
4927  *
4928  * Notice that callers of this function, unlike in the case of the inverse
4929  * operation, would typically need to call this with dst and src being
4930  * different registers, since they would otherwise corrupt the original
4931  * 64-bit data they are about to write. Because of this the function checks
4932  * that the src and dst regions involved in the operation do not overlap.
4933  */
4934 fs_reg
shuffle_64bit_data_for_32bit_write(const fs_builder & bld,const fs_reg & src,uint32_t components)4935 shuffle_64bit_data_for_32bit_write(const fs_builder &bld,
4936                                    const fs_reg &src,
4937                                    uint32_t components)
4938 {
4939    assert(type_sz(src.type) == 8);
4940 
4941    fs_reg dst = bld.vgrf(BRW_REGISTER_TYPE_D, 2 * components);
4942 
4943    for (unsigned i = 0; i < components; i++) {
4944       const fs_reg component_i = offset(src, bld, i);
4945       bld.MOV(offset(dst, bld, 2 * i), subscript(component_i, dst.type, 0));
4946       bld.MOV(offset(dst, bld, 2 * i + 1), subscript(component_i, dst.type, 1));
4947    }
4948 
4949    return dst;
4950 }
4951 
4952 void
shuffle_16bit_data_for_32bit_write(const fs_builder & bld,const fs_reg & dst,const fs_reg & src,uint32_t components)4953 shuffle_16bit_data_for_32bit_write(const fs_builder &bld,
4954                                    const fs_reg &dst,
4955                                    const fs_reg &src,
4956                                    uint32_t components)
4957 {
4958    assert(type_sz(src.type) == 2);
4959    assert(type_sz(dst.type) == 4);
4960 
4961    /* A temporary is used to shuffle the 16-bit data of each component in the
4962     * 32-bit data vector. We can't write directly to dst because it can be the
4963     * same register as src and in that case the first MOV in the loop below
4964     * would overwrite the data read in the second MOV.
4965     */
4966    fs_reg tmp = bld.vgrf(dst.type);
4967 
4968    for (unsigned i = 0; i < components; i++) {
4969       const fs_reg component_i = offset(src, bld, i);
4970       bld.MOV(subscript(tmp, src.type, i % 2), component_i);
4971       if (i % 2) {
4972          bld.MOV(offset(dst, bld, i / 2), tmp);
4973       }
4974    }
4975    if (components % 2) {
4976       bld.MOV(offset(dst, bld, components / 2), tmp);
4977    }
4978 }
4979 
4980 fs_reg
setup_imm_df(const fs_builder & bld,double v)4981 setup_imm_df(const fs_builder &bld, double v)
4982 {
4983    const struct gen_device_info *devinfo = bld.shader->devinfo;
4984    assert(devinfo->gen >= 7);
4985 
4986    if (devinfo->gen >= 8)
4987       return brw_imm_df(v);
4988 
4989    /* gen7.5 does not support DF immediates straighforward but the DIM
4990     * instruction allows to set the 64-bit immediate value.
4991     */
4992    if (devinfo->is_haswell) {
4993       const fs_builder ubld = bld.exec_all().group(1, 0);
4994       fs_reg dst = ubld.vgrf(BRW_REGISTER_TYPE_DF, 1);
4995       ubld.DIM(dst, brw_imm_df(v));
4996       return component(dst, 0);
4997    }
4998 
4999    /* gen7 does not support DF immediates, so we generate a 64-bit constant by
5000     * writing the low 32-bit of the constant to suboffset 0 of a VGRF and
5001     * the high 32-bit to suboffset 4 and then applying a stride of 0.
5002     *
5003     * Alternatively, we could also produce a normal VGRF (without stride 0)
5004     * by writing to all the channels in the VGRF, however, that would hit the
5005     * gen7 bug where we have to split writes that span more than 1 register
5006     * into instructions with a width of 4 (otherwise the write to the second
5007     * register written runs into an execmask hardware bug) which isn't very
5008     * nice.
5009     */
5010    union {
5011       double d;
5012       struct {
5013          uint32_t i1;
5014          uint32_t i2;
5015       };
5016    } di;
5017 
5018    di.d = v;
5019 
5020    const fs_builder ubld = bld.exec_all().group(1, 0);
5021    const fs_reg tmp = ubld.vgrf(BRW_REGISTER_TYPE_UD, 2);
5022    ubld.MOV(tmp, brw_imm_ud(di.i1));
5023    ubld.MOV(horiz_offset(tmp, 1), brw_imm_ud(di.i2));
5024 
5025    return component(retype(tmp, BRW_REGISTER_TYPE_DF), 0);
5026 }
5027