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1 /*
2  * Copyright © 2015 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 "brw_nir.h"
25 #include "brw_vec4.h"
26 #include "brw_vec4_builder.h"
27 #include "brw_vec4_surface_builder.h"
28 #include "brw_program.h"
29 
30 using namespace brw;
31 using namespace brw::surface_access;
32 
33 namespace brw {
34 
35 void
emit_nir_code()36 vec4_visitor::emit_nir_code()
37 {
38    if (nir->num_uniforms > 0)
39       nir_setup_uniforms();
40 
41    nir_setup_system_values();
42 
43    /* get the main function and emit it */
44    nir_foreach_function(function, nir) {
45       assert(strcmp(function->name, "main") == 0);
46       assert(function->impl);
47       nir_emit_impl(function->impl);
48    }
49 }
50 
51 void
nir_setup_system_value_intrinsic(nir_intrinsic_instr * instr)52 vec4_visitor::nir_setup_system_value_intrinsic(nir_intrinsic_instr *instr)
53 {
54    dst_reg *reg;
55 
56    switch (instr->intrinsic) {
57    case nir_intrinsic_load_vertex_id:
58       unreachable("should be lowered by lower_vertex_id().");
59 
60    case nir_intrinsic_load_vertex_id_zero_base:
61       reg = &nir_system_values[SYSTEM_VALUE_VERTEX_ID_ZERO_BASE];
62       if (reg->file == BAD_FILE)
63          *reg = *make_reg_for_system_value(SYSTEM_VALUE_VERTEX_ID_ZERO_BASE);
64       break;
65 
66    case nir_intrinsic_load_base_vertex:
67       reg = &nir_system_values[SYSTEM_VALUE_BASE_VERTEX];
68       if (reg->file == BAD_FILE)
69          *reg = *make_reg_for_system_value(SYSTEM_VALUE_BASE_VERTEX);
70       break;
71 
72    case nir_intrinsic_load_instance_id:
73       reg = &nir_system_values[SYSTEM_VALUE_INSTANCE_ID];
74       if (reg->file == BAD_FILE)
75          *reg = *make_reg_for_system_value(SYSTEM_VALUE_INSTANCE_ID);
76       break;
77 
78    case nir_intrinsic_load_base_instance:
79       reg = &nir_system_values[SYSTEM_VALUE_BASE_INSTANCE];
80       if (reg->file == BAD_FILE)
81          *reg = *make_reg_for_system_value(SYSTEM_VALUE_BASE_INSTANCE);
82       break;
83 
84    case nir_intrinsic_load_draw_id:
85       reg = &nir_system_values[SYSTEM_VALUE_DRAW_ID];
86       if (reg->file == BAD_FILE)
87          *reg = *make_reg_for_system_value(SYSTEM_VALUE_DRAW_ID);
88       break;
89 
90    default:
91       break;
92    }
93 }
94 
95 static bool
setup_system_values_block(nir_block * block,vec4_visitor * v)96 setup_system_values_block(nir_block *block, vec4_visitor *v)
97 {
98    nir_foreach_instr(instr, block) {
99       if (instr->type != nir_instr_type_intrinsic)
100          continue;
101 
102       nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
103       v->nir_setup_system_value_intrinsic(intrin);
104    }
105 
106    return true;
107 }
108 
109 void
nir_setup_system_values()110 vec4_visitor::nir_setup_system_values()
111 {
112    nir_system_values = ralloc_array(mem_ctx, dst_reg, SYSTEM_VALUE_MAX);
113    for (unsigned i = 0; i < SYSTEM_VALUE_MAX; i++) {
114       nir_system_values[i] = dst_reg();
115    }
116 
117    nir_foreach_function(function, nir) {
118       assert(strcmp(function->name, "main") == 0);
119       assert(function->impl);
120       nir_foreach_block(block, function->impl) {
121          setup_system_values_block(block, this);
122       }
123    }
124 }
125 
126 void
nir_setup_uniforms()127 vec4_visitor::nir_setup_uniforms()
128 {
129    uniforms = nir->num_uniforms / 16;
130 }
131 
132 void
nir_emit_impl(nir_function_impl * impl)133 vec4_visitor::nir_emit_impl(nir_function_impl *impl)
134 {
135    nir_locals = ralloc_array(mem_ctx, dst_reg, impl->reg_alloc);
136    for (unsigned i = 0; i < impl->reg_alloc; i++) {
137       nir_locals[i] = dst_reg();
138    }
139 
140    foreach_list_typed(nir_register, reg, node, &impl->registers) {
141       unsigned array_elems =
142          reg->num_array_elems == 0 ? 1 : reg->num_array_elems;
143       const unsigned num_regs = array_elems * DIV_ROUND_UP(reg->bit_size, 32);
144       nir_locals[reg->index] = dst_reg(VGRF, alloc.allocate(num_regs));
145 
146       if (reg->bit_size == 64)
147          nir_locals[reg->index].type = BRW_REGISTER_TYPE_DF;
148    }
149 
150    nir_ssa_values = ralloc_array(mem_ctx, dst_reg, impl->ssa_alloc);
151 
152    nir_emit_cf_list(&impl->body);
153 }
154 
155 void
nir_emit_cf_list(exec_list * list)156 vec4_visitor::nir_emit_cf_list(exec_list *list)
157 {
158    exec_list_validate(list);
159    foreach_list_typed(nir_cf_node, node, node, list) {
160       switch (node->type) {
161       case nir_cf_node_if:
162          nir_emit_if(nir_cf_node_as_if(node));
163          break;
164 
165       case nir_cf_node_loop:
166          nir_emit_loop(nir_cf_node_as_loop(node));
167          break;
168 
169       case nir_cf_node_block:
170          nir_emit_block(nir_cf_node_as_block(node));
171          break;
172 
173       default:
174          unreachable("Invalid CFG node block");
175       }
176    }
177 }
178 
179 void
nir_emit_if(nir_if * if_stmt)180 vec4_visitor::nir_emit_if(nir_if *if_stmt)
181 {
182    /* First, put the condition in f0 */
183    src_reg condition = get_nir_src(if_stmt->condition, BRW_REGISTER_TYPE_D, 1);
184    vec4_instruction *inst = emit(MOV(dst_null_d(), condition));
185    inst->conditional_mod = BRW_CONDITIONAL_NZ;
186 
187    /* We can just predicate based on the X channel, as the condition only
188     * goes on its own line */
189    emit(IF(BRW_PREDICATE_ALIGN16_REPLICATE_X));
190 
191    nir_emit_cf_list(&if_stmt->then_list);
192 
193    /* note: if the else is empty, dead CF elimination will remove it */
194    emit(BRW_OPCODE_ELSE);
195 
196    nir_emit_cf_list(&if_stmt->else_list);
197 
198    emit(BRW_OPCODE_ENDIF);
199 }
200 
201 void
nir_emit_loop(nir_loop * loop)202 vec4_visitor::nir_emit_loop(nir_loop *loop)
203 {
204    emit(BRW_OPCODE_DO);
205 
206    nir_emit_cf_list(&loop->body);
207 
208    emit(BRW_OPCODE_WHILE);
209 }
210 
211 void
nir_emit_block(nir_block * block)212 vec4_visitor::nir_emit_block(nir_block *block)
213 {
214    nir_foreach_instr(instr, block) {
215       nir_emit_instr(instr);
216    }
217 }
218 
219 void
nir_emit_instr(nir_instr * instr)220 vec4_visitor::nir_emit_instr(nir_instr *instr)
221 {
222    base_ir = instr;
223 
224    switch (instr->type) {
225    case nir_instr_type_load_const:
226       nir_emit_load_const(nir_instr_as_load_const(instr));
227       break;
228 
229    case nir_instr_type_intrinsic:
230       nir_emit_intrinsic(nir_instr_as_intrinsic(instr));
231       break;
232 
233    case nir_instr_type_alu:
234       nir_emit_alu(nir_instr_as_alu(instr));
235       break;
236 
237    case nir_instr_type_jump:
238       nir_emit_jump(nir_instr_as_jump(instr));
239       break;
240 
241    case nir_instr_type_tex:
242       nir_emit_texture(nir_instr_as_tex(instr));
243       break;
244 
245    case nir_instr_type_ssa_undef:
246       nir_emit_undef(nir_instr_as_ssa_undef(instr));
247       break;
248 
249    default:
250       fprintf(stderr, "VS instruction not yet implemented by NIR->vec4\n");
251       break;
252    }
253 }
254 
255 static dst_reg
dst_reg_for_nir_reg(vec4_visitor * v,nir_register * nir_reg,unsigned base_offset,nir_src * indirect)256 dst_reg_for_nir_reg(vec4_visitor *v, nir_register *nir_reg,
257                     unsigned base_offset, nir_src *indirect)
258 {
259    dst_reg reg;
260 
261    reg = v->nir_locals[nir_reg->index];
262    if (nir_reg->bit_size == 64)
263       reg.type = BRW_REGISTER_TYPE_DF;
264    reg = offset(reg, 8, base_offset);
265    if (indirect) {
266       reg.reladdr =
267          new(v->mem_ctx) src_reg(v->get_nir_src(*indirect,
268                                                 BRW_REGISTER_TYPE_D,
269                                                 1));
270    }
271    return reg;
272 }
273 
274 dst_reg
get_nir_dest(const nir_dest & dest)275 vec4_visitor::get_nir_dest(const nir_dest &dest)
276 {
277    if (dest.is_ssa) {
278       dst_reg dst =
279          dst_reg(VGRF, alloc.allocate(DIV_ROUND_UP(dest.ssa.bit_size, 32)));
280       if (dest.ssa.bit_size == 64)
281          dst.type = BRW_REGISTER_TYPE_DF;
282       nir_ssa_values[dest.ssa.index] = dst;
283       return dst;
284    } else {
285       return dst_reg_for_nir_reg(this, dest.reg.reg, dest.reg.base_offset,
286                                  dest.reg.indirect);
287    }
288 }
289 
290 dst_reg
get_nir_dest(const nir_dest & dest,enum brw_reg_type type)291 vec4_visitor::get_nir_dest(const nir_dest &dest, enum brw_reg_type type)
292 {
293    return retype(get_nir_dest(dest), type);
294 }
295 
296 dst_reg
get_nir_dest(const nir_dest & dest,nir_alu_type type)297 vec4_visitor::get_nir_dest(const nir_dest &dest, nir_alu_type type)
298 {
299    return get_nir_dest(dest, brw_type_for_nir_type(type));
300 }
301 
302 src_reg
get_nir_src(const nir_src & src,enum brw_reg_type type,unsigned num_components)303 vec4_visitor::get_nir_src(const nir_src &src, enum brw_reg_type type,
304                           unsigned num_components)
305 {
306    dst_reg reg;
307 
308    if (src.is_ssa) {
309       assert(src.ssa != NULL);
310       reg = nir_ssa_values[src.ssa->index];
311    }
312    else {
313       reg = dst_reg_for_nir_reg(this, src.reg.reg, src.reg.base_offset,
314                                 src.reg.indirect);
315    }
316 
317    reg = retype(reg, type);
318 
319    src_reg reg_as_src = src_reg(reg);
320    reg_as_src.swizzle = brw_swizzle_for_size(num_components);
321    return reg_as_src;
322 }
323 
324 src_reg
get_nir_src(const nir_src & src,nir_alu_type type,unsigned num_components)325 vec4_visitor::get_nir_src(const nir_src &src, nir_alu_type type,
326                           unsigned num_components)
327 {
328    return get_nir_src(src, brw_type_for_nir_type(type), num_components);
329 }
330 
331 src_reg
get_nir_src(const nir_src & src,unsigned num_components)332 vec4_visitor::get_nir_src(const nir_src &src, unsigned num_components)
333 {
334    /* if type is not specified, default to signed int */
335    return get_nir_src(src, nir_type_int32, num_components);
336 }
337 
338 src_reg
get_indirect_offset(nir_intrinsic_instr * instr)339 vec4_visitor::get_indirect_offset(nir_intrinsic_instr *instr)
340 {
341    nir_src *offset_src = nir_get_io_offset_src(instr);
342    nir_const_value *const_value = nir_src_as_const_value(*offset_src);
343 
344    if (const_value) {
345       /* The only constant offset we should find is 0.  brw_nir.c's
346        * add_const_offset_to_base() will fold other constant offsets
347        * into instr->const_index[0].
348        */
349       assert(const_value->u32[0] == 0);
350       return src_reg();
351    }
352 
353    return get_nir_src(*offset_src, BRW_REGISTER_TYPE_UD, 1);
354 }
355 
356 void
nir_emit_load_const(nir_load_const_instr * instr)357 vec4_visitor::nir_emit_load_const(nir_load_const_instr *instr)
358 {
359    dst_reg reg;
360 
361    if (instr->def.bit_size == 64) {
362       reg = dst_reg(VGRF, alloc.allocate(2));
363       reg.type = BRW_REGISTER_TYPE_DF;
364    } else {
365       reg = dst_reg(VGRF, alloc.allocate(1));
366       reg.type = BRW_REGISTER_TYPE_D;
367    }
368 
369    unsigned remaining = brw_writemask_for_size(instr->def.num_components);
370 
371    /* @FIXME: consider emitting vector operations to save some MOVs in
372     * cases where the components are representable in 8 bits.
373     * For now, we emit a MOV for each distinct value.
374     */
375    for (unsigned i = 0; i < instr->def.num_components; i++) {
376       unsigned writemask = 1 << i;
377 
378       if ((remaining & writemask) == 0)
379          continue;
380 
381       for (unsigned j = i; j < instr->def.num_components; j++) {
382          if ((instr->def.bit_size == 32 &&
383               instr->value.u32[i] == instr->value.u32[j]) ||
384              (instr->def.bit_size == 64 &&
385               instr->value.f64[i] == instr->value.f64[j])) {
386             writemask |= 1 << j;
387          }
388       }
389 
390       reg.writemask = writemask;
391       if (instr->def.bit_size == 64) {
392          emit(MOV(reg, setup_imm_df(instr->value.f64[i])));
393       } else {
394          emit(MOV(reg, brw_imm_d(instr->value.i32[i])));
395       }
396 
397       remaining &= ~writemask;
398    }
399 
400    /* Set final writemask */
401    reg.writemask = brw_writemask_for_size(instr->def.num_components);
402 
403    nir_ssa_values[instr->def.index] = reg;
404 }
405 
406 void
nir_emit_intrinsic(nir_intrinsic_instr * instr)407 vec4_visitor::nir_emit_intrinsic(nir_intrinsic_instr *instr)
408 {
409    dst_reg dest;
410    src_reg src;
411 
412    switch (instr->intrinsic) {
413 
414    case nir_intrinsic_load_input: {
415       nir_const_value *const_offset = nir_src_as_const_value(instr->src[0]);
416 
417       /* We set EmitNoIndirectInput for VS */
418       assert(const_offset);
419 
420       dest = get_nir_dest(instr->dest);
421       dest.writemask = brw_writemask_for_size(instr->num_components);
422 
423       src = src_reg(ATTR, instr->const_index[0] + const_offset->u32[0],
424                     glsl_type::uvec4_type);
425       src = retype(src, dest.type);
426 
427       bool is_64bit = nir_dest_bit_size(instr->dest) == 64;
428       if (is_64bit) {
429          dst_reg tmp = dst_reg(this, glsl_type::dvec4_type);
430          src.swizzle = BRW_SWIZZLE_XYZW;
431          shuffle_64bit_data(tmp, src, false);
432          emit(MOV(dest, src_reg(tmp)));
433       } else {
434          /* Swizzle source based on component layout qualifier */
435          src.swizzle = BRW_SWZ_COMP_INPUT(nir_intrinsic_component(instr));
436          emit(MOV(dest, src));
437       }
438       break;
439    }
440 
441    case nir_intrinsic_store_output: {
442       nir_const_value *const_offset = nir_src_as_const_value(instr->src[1]);
443       assert(const_offset);
444 
445       int varying = instr->const_index[0] + const_offset->u32[0];
446 
447       bool is_64bit = nir_src_bit_size(instr->src[0]) == 64;
448       if (is_64bit) {
449          src_reg data;
450          src = get_nir_src(instr->src[0], BRW_REGISTER_TYPE_DF,
451                            instr->num_components);
452          data = src_reg(this, glsl_type::dvec4_type);
453          shuffle_64bit_data(dst_reg(data), src, true);
454          src = retype(data, BRW_REGISTER_TYPE_F);
455       } else {
456          src = get_nir_src(instr->src[0], BRW_REGISTER_TYPE_F,
457                            instr->num_components);
458       }
459 
460       unsigned c = nir_intrinsic_component(instr);
461       output_reg[varying][c] = dst_reg(src);
462       output_num_components[varying][c] = instr->num_components;
463 
464       unsigned num_components = instr->num_components;
465       if (is_64bit)
466          num_components *= 2;
467 
468       output_reg[varying][c] = dst_reg(src);
469       output_num_components[varying][c] = MIN2(4, num_components);
470 
471       if (is_64bit && num_components > 4) {
472          assert(num_components <= 8);
473          output_reg[varying + 1][c] = byte_offset(dst_reg(src), REG_SIZE);
474          output_num_components[varying + 1][c] = num_components - 4;
475       }
476       break;
477    }
478 
479    case nir_intrinsic_get_buffer_size: {
480       nir_const_value *const_uniform_block = nir_src_as_const_value(instr->src[0]);
481       unsigned ssbo_index = const_uniform_block ? const_uniform_block->u32[0] : 0;
482 
483       const unsigned index =
484          prog_data->base.binding_table.ssbo_start + ssbo_index;
485       dst_reg result_dst = get_nir_dest(instr->dest);
486       vec4_instruction *inst = new(mem_ctx)
487          vec4_instruction(VS_OPCODE_GET_BUFFER_SIZE, result_dst);
488 
489       inst->base_mrf = 2;
490       inst->mlen = 1; /* always at least one */
491       inst->src[1] = brw_imm_ud(index);
492 
493       /* MRF for the first parameter */
494       src_reg lod = brw_imm_d(0);
495       int param_base = inst->base_mrf;
496       int writemask = WRITEMASK_X;
497       emit(MOV(dst_reg(MRF, param_base, glsl_type::int_type, writemask), lod));
498 
499       emit(inst);
500 
501       brw_mark_surface_used(&prog_data->base, index);
502       break;
503    }
504 
505    case nir_intrinsic_store_ssbo: {
506       assert(devinfo->gen >= 7);
507 
508       /* Block index */
509       src_reg surf_index;
510       nir_const_value *const_uniform_block =
511          nir_src_as_const_value(instr->src[1]);
512       if (const_uniform_block) {
513          unsigned index = prog_data->base.binding_table.ssbo_start +
514                           const_uniform_block->u32[0];
515          surf_index = brw_imm_ud(index);
516          brw_mark_surface_used(&prog_data->base, index);
517       } else {
518          surf_index = src_reg(this, glsl_type::uint_type);
519          emit(ADD(dst_reg(surf_index), get_nir_src(instr->src[1], 1),
520                   brw_imm_ud(prog_data->base.binding_table.ssbo_start)));
521          surf_index = emit_uniformize(surf_index);
522 
523          brw_mark_surface_used(&prog_data->base,
524                                prog_data->base.binding_table.ssbo_start +
525                                nir->info->num_ssbos - 1);
526       }
527 
528       /* Offset */
529       src_reg offset_reg;
530       nir_const_value *const_offset = nir_src_as_const_value(instr->src[2]);
531       if (const_offset) {
532          offset_reg = brw_imm_ud(const_offset->u32[0]);
533       } else {
534          offset_reg = get_nir_src(instr->src[2], 1);
535       }
536 
537       /* Value */
538       src_reg val_reg = get_nir_src(instr->src[0], BRW_REGISTER_TYPE_F, 4);
539 
540       /* Writemask */
541       unsigned write_mask = instr->const_index[0];
542 
543       /* IvyBridge does not have a native SIMD4x2 untyped write message so untyped
544        * writes will use SIMD8 mode. In order to hide this and keep symmetry across
545        * typed and untyped messages and across hardware platforms, the
546        * current implementation of the untyped messages will transparently convert
547        * the SIMD4x2 payload into an equivalent SIMD8 payload by transposing it
548        * and enabling only channel X on the SEND instruction.
549        *
550        * The above, works well for full vector writes, but not for partial writes
551        * where we want to write some channels and not others, like when we have
552        * code such as v.xyw = vec3(1,2,4). Because the untyped write messages are
553        * quite restrictive with regards to the channel enables we can configure in
554        * the message descriptor (not all combinations are allowed) we cannot simply
555        * implement these scenarios with a single message while keeping the
556        * aforementioned symmetry in the implementation. For now we de decided that
557        * it is better to keep the symmetry to reduce complexity, so in situations
558        * such as the one described we end up emitting two untyped write messages
559        * (one for xy and another for w).
560        *
561        * The code below packs consecutive channels into a single write message,
562        * detects gaps in the vector write and if needed, sends a second message
563        * with the remaining channels. If in the future we decide that we want to
564        * emit a single message at the expense of losing the symmetry in the
565        * implementation we can:
566        *
567        * 1) For IvyBridge: Only use the red channel of the untyped write SIMD8
568        *    message payload. In this mode we can write up to 8 offsets and dwords
569        *    to the red channel only (for the two vec4s in the SIMD4x2 execution)
570        *    and select which of the 8 channels carry data to write by setting the
571        *    appropriate writemask in the dst register of the SEND instruction.
572        *    It would require to write a new generator opcode specifically for
573        *    IvyBridge since we would need to prepare a SIMD8 payload that could
574        *    use any channel, not just X.
575        *
576        * 2) For Haswell+: Simply send a single write message but set the writemask
577        *    on the dst of the SEND instruction to select the channels we want to
578        *    write. It would require to modify the current messages to receive
579        *    and honor the writemask provided.
580        */
581       const vec4_builder bld = vec4_builder(this).at_end()
582                                .annotate(current_annotation, base_ir);
583 
584       unsigned type_slots = nir_src_bit_size(instr->src[0]) / 32;
585       if (type_slots == 2) {
586          dst_reg tmp = dst_reg(this, glsl_type::dvec4_type);
587          shuffle_64bit_data(tmp, retype(val_reg, tmp.type), true);
588          val_reg = src_reg(retype(tmp, BRW_REGISTER_TYPE_F));
589       }
590 
591       uint8_t swizzle[4] = { 0, 0, 0, 0};
592       int num_channels = 0;
593       unsigned skipped_channels = 0;
594       int num_components = instr->num_components;
595       for (int i = 0; i < num_components; i++) {
596          /* Read components Z/W of a dvec from the appropriate place. We will
597           * also have to adjust the swizzle (we do that with the '% 4' below)
598           */
599          if (i == 2 && type_slots == 2)
600             val_reg = byte_offset(val_reg, REG_SIZE);
601 
602          /* Check if this channel needs to be written. If so, record the
603           * channel we need to take the data from in the swizzle array
604           */
605          int component_mask = 1 << i;
606          int write_test = write_mask & component_mask;
607          if (write_test) {
608             /* If we are writing doubles we have to write 2 channels worth of
609              * of data (64 bits) for each double component.
610              */
611             swizzle[num_channels++] = (i * type_slots) % 4;
612             if (type_slots == 2)
613                swizzle[num_channels++] = (i * type_slots + 1) % 4;
614          }
615 
616          /* If we don't have to write this channel it means we have a gap in the
617           * vector, so write the channels we accumulated until now, if any. Do
618           * the same if this was the last component in the vector, if we have
619           * enough channels for a full vec4 write or if we have processed
620           * components XY of a dvec (since components ZW are not in the same
621           * SIMD register)
622           */
623          if (!write_test || i == num_components - 1 || num_channels == 4 ||
624              (i == 1 && type_slots == 2)) {
625             if (num_channels > 0) {
626                /* We have channels to write, so update the offset we need to
627                 * write at to skip the channels we skipped, if any.
628                 */
629                if (skipped_channels > 0) {
630                   if (offset_reg.file == IMM) {
631                      offset_reg.ud += 4 * skipped_channels;
632                   } else {
633                      emit(ADD(dst_reg(offset_reg), offset_reg,
634                               brw_imm_ud(4 * skipped_channels)));
635                   }
636                }
637 
638                /* Swizzle the data register so we take the data from the channels
639                 * we need to write and send the write message. This will write
640                 * num_channels consecutive dwords starting at offset.
641                 */
642                val_reg.swizzle =
643                   BRW_SWIZZLE4(swizzle[0], swizzle[1], swizzle[2], swizzle[3]);
644                emit_untyped_write(bld, surf_index, offset_reg, val_reg,
645                                   1 /* dims */, num_channels /* size */,
646                                   BRW_PREDICATE_NONE);
647 
648                /* If we have to do a second write we will have to update the
649                 * offset so that we jump over the channels we have just written
650                 * now.
651                 */
652                skipped_channels = num_channels;
653 
654                /* Restart the count for the next write message */
655                num_channels = 0;
656             }
657 
658             /* If we didn't write the channel, increase skipped count */
659             if (!write_test)
660                skipped_channels += type_slots;
661          }
662       }
663 
664       break;
665    }
666 
667    case nir_intrinsic_load_ssbo: {
668       assert(devinfo->gen >= 7);
669 
670       nir_const_value *const_uniform_block =
671          nir_src_as_const_value(instr->src[0]);
672 
673       src_reg surf_index;
674       if (const_uniform_block) {
675          unsigned index = prog_data->base.binding_table.ssbo_start +
676                           const_uniform_block->u32[0];
677          surf_index = brw_imm_ud(index);
678 
679          brw_mark_surface_used(&prog_data->base, index);
680       } else {
681          surf_index = src_reg(this, glsl_type::uint_type);
682          emit(ADD(dst_reg(surf_index), get_nir_src(instr->src[0], 1),
683                   brw_imm_ud(prog_data->base.binding_table.ssbo_start)));
684          surf_index = emit_uniformize(surf_index);
685 
686          /* Assume this may touch any UBO. It would be nice to provide
687           * a tighter bound, but the array information is already lowered away.
688           */
689          brw_mark_surface_used(&prog_data->base,
690                                prog_data->base.binding_table.ssbo_start +
691                                nir->info->num_ssbos - 1);
692       }
693 
694       src_reg offset_reg;
695       nir_const_value *const_offset = nir_src_as_const_value(instr->src[1]);
696       if (const_offset) {
697          offset_reg = brw_imm_ud(const_offset->u32[0]);
698       } else {
699          offset_reg = get_nir_src(instr->src[1], 1);
700       }
701 
702       /* Read the vector */
703       const vec4_builder bld = vec4_builder(this).at_end()
704          .annotate(current_annotation, base_ir);
705 
706       src_reg read_result;
707       dst_reg dest = get_nir_dest(instr->dest);
708       if (type_sz(dest.type) < 8) {
709          read_result = emit_untyped_read(bld, surf_index, offset_reg,
710                                          1 /* dims */, 4 /* size*/,
711                                          BRW_PREDICATE_NONE);
712       } else {
713          src_reg shuffled = src_reg(this, glsl_type::dvec4_type);
714 
715          src_reg temp;
716          temp = emit_untyped_read(bld, surf_index, offset_reg,
717                                   1 /* dims */, 4 /* size*/,
718                                   BRW_PREDICATE_NONE);
719          emit(MOV(dst_reg(retype(shuffled, temp.type)), temp));
720 
721          if (offset_reg.file == IMM)
722             offset_reg.ud += 16;
723          else
724             emit(ADD(dst_reg(offset_reg), offset_reg, brw_imm_ud(16)));
725 
726          temp = emit_untyped_read(bld, surf_index, offset_reg,
727                                   1 /* dims */, 4 /* size*/,
728                                   BRW_PREDICATE_NONE);
729          emit(MOV(dst_reg(retype(byte_offset(shuffled, REG_SIZE), temp.type)),
730                   temp));
731 
732          read_result = src_reg(this, glsl_type::dvec4_type);
733          shuffle_64bit_data(dst_reg(read_result), shuffled, false);
734       }
735 
736       read_result.type = dest.type;
737       read_result.swizzle = brw_swizzle_for_size(instr->num_components);
738       emit(MOV(dest, read_result));
739       break;
740    }
741 
742    case nir_intrinsic_ssbo_atomic_add:
743       nir_emit_ssbo_atomic(BRW_AOP_ADD, instr);
744       break;
745    case nir_intrinsic_ssbo_atomic_imin:
746       nir_emit_ssbo_atomic(BRW_AOP_IMIN, instr);
747       break;
748    case nir_intrinsic_ssbo_atomic_umin:
749       nir_emit_ssbo_atomic(BRW_AOP_UMIN, instr);
750       break;
751    case nir_intrinsic_ssbo_atomic_imax:
752       nir_emit_ssbo_atomic(BRW_AOP_IMAX, instr);
753       break;
754    case nir_intrinsic_ssbo_atomic_umax:
755       nir_emit_ssbo_atomic(BRW_AOP_UMAX, instr);
756       break;
757    case nir_intrinsic_ssbo_atomic_and:
758       nir_emit_ssbo_atomic(BRW_AOP_AND, instr);
759       break;
760    case nir_intrinsic_ssbo_atomic_or:
761       nir_emit_ssbo_atomic(BRW_AOP_OR, instr);
762       break;
763    case nir_intrinsic_ssbo_atomic_xor:
764       nir_emit_ssbo_atomic(BRW_AOP_XOR, instr);
765       break;
766    case nir_intrinsic_ssbo_atomic_exchange:
767       nir_emit_ssbo_atomic(BRW_AOP_MOV, instr);
768       break;
769    case nir_intrinsic_ssbo_atomic_comp_swap:
770       nir_emit_ssbo_atomic(BRW_AOP_CMPWR, instr);
771       break;
772 
773    case nir_intrinsic_load_vertex_id:
774       unreachable("should be lowered by lower_vertex_id()");
775 
776    case nir_intrinsic_load_vertex_id_zero_base:
777    case nir_intrinsic_load_base_vertex:
778    case nir_intrinsic_load_instance_id:
779    case nir_intrinsic_load_base_instance:
780    case nir_intrinsic_load_draw_id:
781    case nir_intrinsic_load_invocation_id: {
782       gl_system_value sv = nir_system_value_from_intrinsic(instr->intrinsic);
783       src_reg val = src_reg(nir_system_values[sv]);
784       assert(val.file != BAD_FILE);
785       dest = get_nir_dest(instr->dest, val.type);
786       emit(MOV(dest, val));
787       break;
788    }
789 
790    case nir_intrinsic_load_uniform: {
791       /* Offsets are in bytes but they should always be multiples of 4 */
792       assert(nir_intrinsic_base(instr) % 4 == 0);
793 
794       dest = get_nir_dest(instr->dest);
795 
796       src = src_reg(dst_reg(UNIFORM, nir_intrinsic_base(instr) / 16));
797       src.type = dest.type;
798 
799       /* Uniforms don't actually have to be vec4 aligned.  In the case that
800        * it isn't, we have to use a swizzle to shift things around.  They
801        * do still have the std140 alignment requirement that vec2's have to
802        * be vec2-aligned and vec3's and vec4's have to be vec4-aligned.
803        *
804        * The swizzle also works in the indirect case as the generator adds
805        * the swizzle to the offset for us.
806        */
807       unsigned shift = (nir_intrinsic_base(instr) % 16) / 4;
808       assert(shift + instr->num_components <= 4);
809 
810       nir_const_value *const_offset = nir_src_as_const_value(instr->src[0]);
811       if (const_offset) {
812          /* Offsets are in bytes but they should always be multiples of 4 */
813          assert(const_offset->u32[0] % 4 == 0);
814 
815          unsigned offset = const_offset->u32[0] + shift * 4;
816          src.offset = ROUND_DOWN_TO(offset, 16);
817          shift = (offset % 16) / 4;
818          src.swizzle += BRW_SWIZZLE4(shift, shift, shift, shift);
819 
820          emit(MOV(dest, src));
821       } else {
822          src.swizzle += BRW_SWIZZLE4(shift, shift, shift, shift);
823 
824          src_reg indirect = get_nir_src(instr->src[0], BRW_REGISTER_TYPE_UD, 1);
825 
826          /* MOV_INDIRECT is going to stomp the whole thing anyway */
827          dest.writemask = WRITEMASK_XYZW;
828 
829          emit(SHADER_OPCODE_MOV_INDIRECT, dest, src,
830               indirect, brw_imm_ud(instr->const_index[1]));
831       }
832       break;
833    }
834 
835    case nir_intrinsic_atomic_counter_read:
836    case nir_intrinsic_atomic_counter_inc:
837    case nir_intrinsic_atomic_counter_dec: {
838       unsigned surf_index = prog_data->base.binding_table.abo_start +
839          (unsigned) instr->const_index[0];
840       const vec4_builder bld =
841          vec4_builder(this).at_end().annotate(current_annotation, base_ir);
842 
843       /* Get some metadata from the image intrinsic. */
844       const nir_intrinsic_info *info = &nir_intrinsic_infos[instr->intrinsic];
845 
846       /* Get the arguments of the atomic intrinsic. */
847       src_reg offset = get_nir_src(instr->src[0], nir_type_int32,
848                                    instr->num_components);
849       const src_reg surface = brw_imm_ud(surf_index);
850       const src_reg src0 = (info->num_srcs >= 2
851                            ? get_nir_src(instr->src[1]) : src_reg());
852       const src_reg src1 = (info->num_srcs >= 3
853                            ? get_nir_src(instr->src[2]) : src_reg());
854 
855       src_reg tmp;
856 
857       dest = get_nir_dest(instr->dest);
858 
859       if (instr->intrinsic == nir_intrinsic_atomic_counter_read) {
860          tmp = emit_untyped_read(bld, surface, offset, 1, 1);
861       } else {
862          tmp = emit_untyped_atomic(bld, surface, offset,
863                                    src0, src1,
864                                    1, 1,
865                                    get_atomic_counter_op(instr->intrinsic));
866       }
867 
868       bld.MOV(retype(dest, tmp.type), tmp);
869       brw_mark_surface_used(stage_prog_data, surf_index);
870       break;
871    }
872 
873    case nir_intrinsic_load_ubo: {
874       nir_const_value *const_block_index = nir_src_as_const_value(instr->src[0]);
875       src_reg surf_index;
876 
877       dest = get_nir_dest(instr->dest);
878 
879       if (const_block_index) {
880          /* The block index is a constant, so just emit the binding table entry
881           * as an immediate.
882           */
883          const unsigned index = prog_data->base.binding_table.ubo_start +
884                                 const_block_index->u32[0];
885          surf_index = brw_imm_ud(index);
886          brw_mark_surface_used(&prog_data->base, index);
887       } else {
888          /* The block index is not a constant. Evaluate the index expression
889           * per-channel and add the base UBO index; we have to select a value
890           * from any live channel.
891           */
892          surf_index = src_reg(this, glsl_type::uint_type);
893          emit(ADD(dst_reg(surf_index), get_nir_src(instr->src[0], nir_type_int32,
894                                                    instr->num_components),
895                   brw_imm_ud(prog_data->base.binding_table.ubo_start)));
896          surf_index = emit_uniformize(surf_index);
897 
898          /* Assume this may touch any UBO. It would be nice to provide
899           * a tighter bound, but the array information is already lowered away.
900           */
901          brw_mark_surface_used(&prog_data->base,
902                                prog_data->base.binding_table.ubo_start +
903                                nir->info->num_ubos - 1);
904       }
905 
906       src_reg offset_reg;
907       nir_const_value *const_offset = nir_src_as_const_value(instr->src[1]);
908       if (const_offset) {
909          offset_reg = brw_imm_ud(const_offset->u32[0] & ~15);
910       } else {
911          offset_reg = get_nir_src(instr->src[1], nir_type_uint32, 1);
912       }
913 
914       src_reg packed_consts;
915       if (nir_dest_bit_size(instr->dest) == 32) {
916          packed_consts = src_reg(this, glsl_type::vec4_type);
917          emit_pull_constant_load_reg(dst_reg(packed_consts),
918                                      surf_index,
919                                      offset_reg,
920                                      NULL, NULL /* before_block/inst */);
921       } else {
922          src_reg temp = src_reg(this, glsl_type::dvec4_type);
923          src_reg temp_float = retype(temp, BRW_REGISTER_TYPE_F);
924 
925          emit_pull_constant_load_reg(dst_reg(temp_float),
926                                      surf_index, offset_reg, NULL, NULL);
927          if (offset_reg.file == IMM)
928             offset_reg.ud += 16;
929          else
930             emit(ADD(dst_reg(offset_reg), offset_reg, brw_imm_ud(16u)));
931          emit_pull_constant_load_reg(dst_reg(byte_offset(temp_float, REG_SIZE)),
932                                      surf_index, offset_reg, NULL, NULL);
933 
934          packed_consts = src_reg(this, glsl_type::dvec4_type);
935          shuffle_64bit_data(dst_reg(packed_consts), temp, false);
936       }
937 
938       packed_consts.swizzle = brw_swizzle_for_size(instr->num_components);
939       if (const_offset) {
940          unsigned type_size = type_sz(dest.type);
941          packed_consts.swizzle +=
942             BRW_SWIZZLE4(const_offset->u32[0] % 16 / type_size,
943                          const_offset->u32[0] % 16 / type_size,
944                          const_offset->u32[0] % 16 / type_size,
945                          const_offset->u32[0] % 16 / type_size);
946       }
947 
948       emit(MOV(dest, retype(packed_consts, dest.type)));
949 
950       break;
951    }
952 
953    case nir_intrinsic_memory_barrier: {
954       const vec4_builder bld =
955          vec4_builder(this).at_end().annotate(current_annotation, base_ir);
956       const dst_reg tmp = bld.vgrf(BRW_REGISTER_TYPE_UD, 2);
957       bld.emit(SHADER_OPCODE_MEMORY_FENCE, tmp)
958          ->size_written = 2 * REG_SIZE;
959       break;
960    }
961 
962    case nir_intrinsic_shader_clock: {
963       /* We cannot do anything if there is an event, so ignore it for now */
964       const src_reg shader_clock = get_timestamp();
965       const enum brw_reg_type type = brw_type_for_base_type(glsl_type::uvec2_type);
966 
967       dest = get_nir_dest(instr->dest, type);
968       emit(MOV(dest, shader_clock));
969       break;
970    }
971 
972    default:
973       unreachable("Unknown intrinsic");
974    }
975 }
976 
977 void
nir_emit_ssbo_atomic(int op,nir_intrinsic_instr * instr)978 vec4_visitor::nir_emit_ssbo_atomic(int op, nir_intrinsic_instr *instr)
979 {
980    dst_reg dest;
981    if (nir_intrinsic_infos[instr->intrinsic].has_dest)
982       dest = get_nir_dest(instr->dest);
983 
984    src_reg surface;
985    nir_const_value *const_surface = nir_src_as_const_value(instr->src[0]);
986    if (const_surface) {
987       unsigned surf_index = prog_data->base.binding_table.ssbo_start +
988                             const_surface->u32[0];
989       surface = brw_imm_ud(surf_index);
990       brw_mark_surface_used(&prog_data->base, surf_index);
991    } else {
992       surface = src_reg(this, glsl_type::uint_type);
993       emit(ADD(dst_reg(surface), get_nir_src(instr->src[0]),
994                brw_imm_ud(prog_data->base.binding_table.ssbo_start)));
995 
996       /* Assume this may touch any UBO. This is the same we do for other
997        * UBO/SSBO accesses with non-constant surface.
998        */
999       brw_mark_surface_used(&prog_data->base,
1000                             prog_data->base.binding_table.ssbo_start +
1001                             nir->info->num_ssbos - 1);
1002    }
1003 
1004    src_reg offset = get_nir_src(instr->src[1], 1);
1005    src_reg data1 = get_nir_src(instr->src[2], 1);
1006    src_reg data2;
1007    if (op == BRW_AOP_CMPWR)
1008       data2 = get_nir_src(instr->src[3], 1);
1009 
1010    /* Emit the actual atomic operation operation */
1011    const vec4_builder bld =
1012       vec4_builder(this).at_end().annotate(current_annotation, base_ir);
1013 
1014    src_reg atomic_result = emit_untyped_atomic(bld, surface, offset,
1015                                                data1, data2,
1016                                                1 /* dims */, 1 /* rsize */,
1017                                                op,
1018                                                BRW_PREDICATE_NONE);
1019    dest.type = atomic_result.type;
1020    bld.MOV(dest, atomic_result);
1021 }
1022 
1023 static unsigned
brw_swizzle_for_nir_swizzle(uint8_t swizzle[4])1024 brw_swizzle_for_nir_swizzle(uint8_t swizzle[4])
1025 {
1026    return BRW_SWIZZLE4(swizzle[0], swizzle[1], swizzle[2], swizzle[3]);
1027 }
1028 
1029 static enum brw_conditional_mod
brw_conditional_for_nir_comparison(nir_op op)1030 brw_conditional_for_nir_comparison(nir_op op)
1031 {
1032    switch (op) {
1033    case nir_op_flt:
1034    case nir_op_ilt:
1035    case nir_op_ult:
1036       return BRW_CONDITIONAL_L;
1037 
1038    case nir_op_fge:
1039    case nir_op_ige:
1040    case nir_op_uge:
1041       return BRW_CONDITIONAL_GE;
1042 
1043    case nir_op_feq:
1044    case nir_op_ieq:
1045    case nir_op_ball_fequal2:
1046    case nir_op_ball_iequal2:
1047    case nir_op_ball_fequal3:
1048    case nir_op_ball_iequal3:
1049    case nir_op_ball_fequal4:
1050    case nir_op_ball_iequal4:
1051       return BRW_CONDITIONAL_Z;
1052 
1053    case nir_op_fne:
1054    case nir_op_ine:
1055    case nir_op_bany_fnequal2:
1056    case nir_op_bany_inequal2:
1057    case nir_op_bany_fnequal3:
1058    case nir_op_bany_inequal3:
1059    case nir_op_bany_fnequal4:
1060    case nir_op_bany_inequal4:
1061       return BRW_CONDITIONAL_NZ;
1062 
1063    default:
1064       unreachable("not reached: bad operation for comparison");
1065    }
1066 }
1067 
1068 bool
optimize_predicate(nir_alu_instr * instr,enum brw_predicate * predicate)1069 vec4_visitor::optimize_predicate(nir_alu_instr *instr,
1070                                  enum brw_predicate *predicate)
1071 {
1072    if (!instr->src[0].src.is_ssa ||
1073        instr->src[0].src.ssa->parent_instr->type != nir_instr_type_alu)
1074       return false;
1075 
1076    nir_alu_instr *cmp_instr =
1077       nir_instr_as_alu(instr->src[0].src.ssa->parent_instr);
1078 
1079    switch (cmp_instr->op) {
1080    case nir_op_bany_fnequal2:
1081    case nir_op_bany_inequal2:
1082    case nir_op_bany_fnequal3:
1083    case nir_op_bany_inequal3:
1084    case nir_op_bany_fnequal4:
1085    case nir_op_bany_inequal4:
1086       *predicate = BRW_PREDICATE_ALIGN16_ANY4H;
1087       break;
1088    case nir_op_ball_fequal2:
1089    case nir_op_ball_iequal2:
1090    case nir_op_ball_fequal3:
1091    case nir_op_ball_iequal3:
1092    case nir_op_ball_fequal4:
1093    case nir_op_ball_iequal4:
1094       *predicate = BRW_PREDICATE_ALIGN16_ALL4H;
1095       break;
1096    default:
1097       return false;
1098    }
1099 
1100    unsigned size_swizzle =
1101       brw_swizzle_for_size(nir_op_infos[cmp_instr->op].input_sizes[0]);
1102 
1103    src_reg op[2];
1104    assert(nir_op_infos[cmp_instr->op].num_inputs == 2);
1105    for (unsigned i = 0; i < 2; i++) {
1106       nir_alu_type type = nir_op_infos[cmp_instr->op].input_types[i];
1107       unsigned bit_size = nir_src_bit_size(cmp_instr->src[i].src);
1108       type = (nir_alu_type) (((unsigned) type) | bit_size);
1109       op[i] = get_nir_src(cmp_instr->src[i].src, type, 4);
1110       unsigned base_swizzle =
1111          brw_swizzle_for_nir_swizzle(cmp_instr->src[i].swizzle);
1112       op[i].swizzle = brw_compose_swizzle(size_swizzle, base_swizzle);
1113       op[i].abs = cmp_instr->src[i].abs;
1114       op[i].negate = cmp_instr->src[i].negate;
1115    }
1116 
1117    emit(CMP(dst_null_d(), op[0], op[1],
1118             brw_conditional_for_nir_comparison(cmp_instr->op)));
1119 
1120    return true;
1121 }
1122 
1123 static void
emit_find_msb_using_lzd(const vec4_builder & bld,const dst_reg & dst,const src_reg & src,bool is_signed)1124 emit_find_msb_using_lzd(const vec4_builder &bld,
1125                         const dst_reg &dst,
1126                         const src_reg &src,
1127                         bool is_signed)
1128 {
1129    vec4_instruction *inst;
1130    src_reg temp = src;
1131 
1132    if (is_signed) {
1133       /* LZD of an absolute value source almost always does the right
1134        * thing.  There are two problem values:
1135        *
1136        * * 0x80000000.  Since abs(0x80000000) == 0x80000000, LZD returns
1137        *   0.  However, findMSB(int(0x80000000)) == 30.
1138        *
1139        * * 0xffffffff.  Since abs(0xffffffff) == 1, LZD returns
1140        *   31.  Section 8.8 (Integer Functions) of the GLSL 4.50 spec says:
1141        *
1142        *    For a value of zero or negative one, -1 will be returned.
1143        *
1144        * * Negative powers of two.  LZD(abs(-(1<<x))) returns x, but
1145        *   findMSB(-(1<<x)) should return x-1.
1146        *
1147        * For all negative number cases, including 0x80000000 and
1148        * 0xffffffff, the correct value is obtained from LZD if instead of
1149        * negating the (already negative) value the logical-not is used.  A
1150        * conditonal logical-not can be achieved in two instructions.
1151        */
1152       temp = src_reg(bld.vgrf(BRW_REGISTER_TYPE_D));
1153 
1154       bld.ASR(dst_reg(temp), src, brw_imm_d(31));
1155       bld.XOR(dst_reg(temp), temp, src);
1156    }
1157 
1158    bld.LZD(retype(dst, BRW_REGISTER_TYPE_UD),
1159            retype(temp, BRW_REGISTER_TYPE_UD));
1160 
1161    /* LZD counts from the MSB side, while GLSL's findMSB() wants the count
1162     * from the LSB side. Subtract the result from 31 to convert the MSB count
1163     * into an LSB count.  If no bits are set, LZD will return 32.  31-32 = -1,
1164     * which is exactly what findMSB() is supposed to return.
1165     */
1166    inst = bld.ADD(dst, retype(src_reg(dst), BRW_REGISTER_TYPE_D),
1167                   brw_imm_d(31));
1168    inst->src[0].negate = true;
1169 }
1170 
1171 void
emit_conversion_from_double(dst_reg dst,src_reg src,bool saturate,brw_reg_type single_type)1172 vec4_visitor::emit_conversion_from_double(dst_reg dst, src_reg src,
1173                                           bool saturate,
1174                                           brw_reg_type single_type)
1175 {
1176    /* BDW PRM vol 15 - workarounds:
1177     * DF->f format conversion for Align16 has wrong emask calculation when
1178     * source is immediate.
1179     */
1180    if (devinfo->gen == 8 && single_type == BRW_REGISTER_TYPE_F &&
1181        src.file == BRW_IMMEDIATE_VALUE) {
1182       vec4_instruction *inst = emit(MOV(dst, brw_imm_f(src.df)));
1183       inst->saturate = saturate;
1184       return;
1185    }
1186 
1187    dst_reg temp = dst_reg(this, glsl_type::dvec4_type);
1188    emit(MOV(temp, src));
1189 
1190    dst_reg temp2 = dst_reg(this, glsl_type::dvec4_type);
1191    temp2 = retype(temp2, single_type);
1192    emit(VEC4_OPCODE_FROM_DOUBLE, temp2, src_reg(temp))
1193       ->size_written = 2 * REG_SIZE;
1194 
1195    vec4_instruction *inst = emit(MOV(dst, src_reg(temp2)));
1196    inst->saturate = saturate;
1197 }
1198 
1199 void
emit_conversion_to_double(dst_reg dst,src_reg src,bool saturate,brw_reg_type single_type)1200 vec4_visitor::emit_conversion_to_double(dst_reg dst, src_reg src,
1201                                         bool saturate,
1202                                         brw_reg_type single_type)
1203 {
1204    dst_reg tmp_dst = dst_reg(src_reg(this, glsl_type::dvec4_type));
1205    src_reg tmp_src = retype(src_reg(this, glsl_type::vec4_type), single_type);
1206    emit(MOV(dst_reg(tmp_src), retype(src, single_type)));
1207    emit(VEC4_OPCODE_TO_DOUBLE, tmp_dst, tmp_src);
1208    vec4_instruction *inst = emit(MOV(dst, src_reg(tmp_dst)));
1209    inst->saturate = saturate;
1210 }
1211 
1212 src_reg
setup_imm_df(double v)1213 vec4_visitor::setup_imm_df(double v)
1214 {
1215    assert(devinfo->gen >= 7);
1216 
1217    if (devinfo->gen >= 8)
1218       return brw_imm_df(v);
1219 
1220    /* gen7.5 does not support DF immediates straighforward but the DIM
1221     * instruction allows to set the 64-bit immediate value.
1222     */
1223    if (devinfo->is_haswell) {
1224       dst_reg dst = retype(dst_reg(VGRF, alloc.allocate(2)), BRW_REGISTER_TYPE_DF);
1225       emit(DIM(dst, brw_imm_df(v)))->force_writemask_all = true;
1226       return swizzle(src_reg(retype(dst, BRW_REGISTER_TYPE_DF)), BRW_SWIZZLE_XXXX);
1227    }
1228 
1229    /* gen7 does not support DF immediates */
1230    union {
1231       double d;
1232       struct {
1233          uint32_t i1;
1234          uint32_t i2;
1235       };
1236    } di;
1237 
1238    di.d = v;
1239 
1240    /* Write the low 32-bit of the constant to the X:UD channel and the
1241     * high 32-bit to the Y:UD channel to build the constant in a VGRF.
1242     * We have to do this twice (offset 0 and offset 1), since a DF VGRF takes
1243     * two SIMD8 registers in SIMD4x2 execution. Finally, return a swizzle
1244     * XXXX so any access to the VGRF only reads the constant data in these
1245     * channels.
1246     */
1247    const dst_reg tmp =
1248       retype(dst_reg(VGRF, alloc.allocate(2)), BRW_REGISTER_TYPE_UD);
1249    for (int n = 0; n < 2; n++) {
1250       emit(MOV(writemask(offset(tmp, 8, n), WRITEMASK_X), brw_imm_ud(di.i1)))
1251          ->force_writemask_all = true;
1252       emit(MOV(writemask(offset(tmp, 8, n), WRITEMASK_Y), brw_imm_ud(di.i2)))
1253          ->force_writemask_all = true;
1254    }
1255 
1256    return swizzle(src_reg(retype(tmp, BRW_REGISTER_TYPE_DF)), BRW_SWIZZLE_XXXX);
1257 }
1258 
1259 void
nir_emit_alu(nir_alu_instr * instr)1260 vec4_visitor::nir_emit_alu(nir_alu_instr *instr)
1261 {
1262    vec4_instruction *inst;
1263 
1264    nir_alu_type dst_type = (nir_alu_type) (nir_op_infos[instr->op].output_type |
1265                                            nir_dest_bit_size(instr->dest.dest));
1266    dst_reg dst = get_nir_dest(instr->dest.dest, dst_type);
1267    dst.writemask = instr->dest.write_mask;
1268 
1269    src_reg op[4];
1270    for (unsigned i = 0; i < nir_op_infos[instr->op].num_inputs; i++) {
1271       nir_alu_type src_type = (nir_alu_type)
1272          (nir_op_infos[instr->op].input_types[i] |
1273           nir_src_bit_size(instr->src[i].src));
1274       op[i] = get_nir_src(instr->src[i].src, src_type, 4);
1275       op[i].swizzle = brw_swizzle_for_nir_swizzle(instr->src[i].swizzle);
1276       op[i].abs = instr->src[i].abs;
1277       op[i].negate = instr->src[i].negate;
1278    }
1279 
1280    switch (instr->op) {
1281    case nir_op_imov:
1282    case nir_op_fmov:
1283       inst = emit(MOV(dst, op[0]));
1284       inst->saturate = instr->dest.saturate;
1285       break;
1286 
1287    case nir_op_vec2:
1288    case nir_op_vec3:
1289    case nir_op_vec4:
1290       unreachable("not reached: should be handled by lower_vec_to_movs()");
1291 
1292    case nir_op_i2f:
1293    case nir_op_u2f:
1294       inst = emit(MOV(dst, op[0]));
1295       inst->saturate = instr->dest.saturate;
1296       break;
1297 
1298    case nir_op_f2i:
1299    case nir_op_f2u:
1300       inst = emit(MOV(dst, op[0]));
1301       break;
1302 
1303    case nir_op_d2f:
1304       emit_conversion_from_double(dst, op[0], instr->dest.saturate,
1305                                   BRW_REGISTER_TYPE_F);
1306       break;
1307 
1308    case nir_op_f2d:
1309       emit_conversion_to_double(dst, op[0], instr->dest.saturate,
1310                                 BRW_REGISTER_TYPE_F);
1311       break;
1312 
1313    case nir_op_d2i:
1314    case nir_op_d2u:
1315       emit_conversion_from_double(dst, op[0], instr->dest.saturate,
1316                                   instr->op == nir_op_d2i ? BRW_REGISTER_TYPE_D :
1317                                                             BRW_REGISTER_TYPE_UD);
1318       break;
1319 
1320    case nir_op_i2d:
1321    case nir_op_u2d:
1322       emit_conversion_to_double(dst, op[0], instr->dest.saturate,
1323                                 instr->op == nir_op_i2d ? BRW_REGISTER_TYPE_D :
1324                                                           BRW_REGISTER_TYPE_UD);
1325       break;
1326 
1327    case nir_op_iadd:
1328       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1329    case nir_op_fadd:
1330       inst = emit(ADD(dst, op[0], op[1]));
1331       inst->saturate = instr->dest.saturate;
1332       break;
1333 
1334    case nir_op_fmul:
1335       inst = emit(MUL(dst, op[0], op[1]));
1336       inst->saturate = instr->dest.saturate;
1337       break;
1338 
1339    case nir_op_imul: {
1340       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1341       if (devinfo->gen < 8) {
1342          nir_const_value *value0 = nir_src_as_const_value(instr->src[0].src);
1343          nir_const_value *value1 = nir_src_as_const_value(instr->src[1].src);
1344 
1345          /* For integer multiplication, the MUL uses the low 16 bits of one of
1346           * the operands (src0 through SNB, src1 on IVB and later). The MACH
1347           * accumulates in the contribution of the upper 16 bits of that
1348           * operand. If we can determine that one of the args is in the low
1349           * 16 bits, though, we can just emit a single MUL.
1350           */
1351          if (value0 && value0->u32[0] < (1 << 16)) {
1352             if (devinfo->gen < 7)
1353                emit(MUL(dst, op[0], op[1]));
1354             else
1355                emit(MUL(dst, op[1], op[0]));
1356          } else if (value1 && value1->u32[0] < (1 << 16)) {
1357             if (devinfo->gen < 7)
1358                emit(MUL(dst, op[1], op[0]));
1359             else
1360                emit(MUL(dst, op[0], op[1]));
1361          } else {
1362             struct brw_reg acc = retype(brw_acc_reg(8), dst.type);
1363 
1364             emit(MUL(acc, op[0], op[1]));
1365             emit(MACH(dst_null_d(), op[0], op[1]));
1366             emit(MOV(dst, src_reg(acc)));
1367          }
1368       } else {
1369 	 emit(MUL(dst, op[0], op[1]));
1370       }
1371       break;
1372    }
1373 
1374    case nir_op_imul_high:
1375    case nir_op_umul_high: {
1376       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1377       struct brw_reg acc = retype(brw_acc_reg(8), dst.type);
1378 
1379       if (devinfo->gen >= 8)
1380          emit(MUL(acc, op[0], retype(op[1], BRW_REGISTER_TYPE_UW)));
1381       else
1382          emit(MUL(acc, op[0], op[1]));
1383 
1384       emit(MACH(dst, op[0], op[1]));
1385       break;
1386    }
1387 
1388    case nir_op_frcp:
1389       inst = emit_math(SHADER_OPCODE_RCP, dst, op[0]);
1390       inst->saturate = instr->dest.saturate;
1391       break;
1392 
1393    case nir_op_fexp2:
1394       inst = emit_math(SHADER_OPCODE_EXP2, dst, op[0]);
1395       inst->saturate = instr->dest.saturate;
1396       break;
1397 
1398    case nir_op_flog2:
1399       inst = emit_math(SHADER_OPCODE_LOG2, dst, op[0]);
1400       inst->saturate = instr->dest.saturate;
1401       break;
1402 
1403    case nir_op_fsin:
1404       inst = emit_math(SHADER_OPCODE_SIN, dst, op[0]);
1405       inst->saturate = instr->dest.saturate;
1406       break;
1407 
1408    case nir_op_fcos:
1409       inst = emit_math(SHADER_OPCODE_COS, dst, op[0]);
1410       inst->saturate = instr->dest.saturate;
1411       break;
1412 
1413    case nir_op_idiv:
1414    case nir_op_udiv:
1415       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1416       emit_math(SHADER_OPCODE_INT_QUOTIENT, dst, op[0], op[1]);
1417       break;
1418 
1419    case nir_op_umod:
1420    case nir_op_irem:
1421       /* According to the sign table for INT DIV in the Ivy Bridge PRM, it
1422        * appears that our hardware just does the right thing for signed
1423        * remainder.
1424        */
1425       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1426       emit_math(SHADER_OPCODE_INT_REMAINDER, dst, op[0], op[1]);
1427       break;
1428 
1429    case nir_op_imod: {
1430       /* Get a regular C-style remainder.  If a % b == 0, set the predicate. */
1431       inst = emit_math(SHADER_OPCODE_INT_REMAINDER, dst, op[0], op[1]);
1432 
1433       /* Math instructions don't support conditional mod */
1434       inst = emit(MOV(dst_null_d(), src_reg(dst)));
1435       inst->conditional_mod = BRW_CONDITIONAL_NZ;
1436 
1437       /* Now, we need to determine if signs of the sources are different.
1438        * When we XOR the sources, the top bit is 0 if they are the same and 1
1439        * if they are different.  We can then use a conditional modifier to
1440        * turn that into a predicate.  This leads us to an XOR.l instruction.
1441        *
1442        * Technically, according to the PRM, you're not allowed to use .l on a
1443        * XOR instruction.  However, emperical experiments and Curro's reading
1444        * of the simulator source both indicate that it's safe.
1445        */
1446       src_reg tmp = src_reg(this, glsl_type::ivec4_type);
1447       inst = emit(XOR(dst_reg(tmp), op[0], op[1]));
1448       inst->predicate = BRW_PREDICATE_NORMAL;
1449       inst->conditional_mod = BRW_CONDITIONAL_L;
1450 
1451       /* If the result of the initial remainder operation is non-zero and the
1452        * two sources have different signs, add in a copy of op[1] to get the
1453        * final integer modulus value.
1454        */
1455       inst = emit(ADD(dst, src_reg(dst), op[1]));
1456       inst->predicate = BRW_PREDICATE_NORMAL;
1457       break;
1458    }
1459 
1460    case nir_op_ldexp:
1461       unreachable("not reached: should be handled by ldexp_to_arith()");
1462 
1463    case nir_op_fsqrt:
1464       inst = emit_math(SHADER_OPCODE_SQRT, dst, op[0]);
1465       inst->saturate = instr->dest.saturate;
1466       break;
1467 
1468    case nir_op_frsq:
1469       inst = emit_math(SHADER_OPCODE_RSQ, dst, op[0]);
1470       inst->saturate = instr->dest.saturate;
1471       break;
1472 
1473    case nir_op_fpow:
1474       inst = emit_math(SHADER_OPCODE_POW, dst, op[0], op[1]);
1475       inst->saturate = instr->dest.saturate;
1476       break;
1477 
1478    case nir_op_uadd_carry: {
1479       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1480       struct brw_reg acc = retype(brw_acc_reg(8), BRW_REGISTER_TYPE_UD);
1481 
1482       emit(ADDC(dst_null_ud(), op[0], op[1]));
1483       emit(MOV(dst, src_reg(acc)));
1484       break;
1485    }
1486 
1487    case nir_op_usub_borrow: {
1488       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1489       struct brw_reg acc = retype(brw_acc_reg(8), BRW_REGISTER_TYPE_UD);
1490 
1491       emit(SUBB(dst_null_ud(), op[0], op[1]));
1492       emit(MOV(dst, src_reg(acc)));
1493       break;
1494    }
1495 
1496    case nir_op_ftrunc:
1497       inst = emit(RNDZ(dst, op[0]));
1498       inst->saturate = instr->dest.saturate;
1499       break;
1500 
1501    case nir_op_fceil: {
1502       src_reg tmp = src_reg(this, glsl_type::float_type);
1503       tmp.swizzle =
1504          brw_swizzle_for_size(instr->src[0].src.is_ssa ?
1505                               instr->src[0].src.ssa->num_components :
1506                               instr->src[0].src.reg.reg->num_components);
1507 
1508       op[0].negate = !op[0].negate;
1509       emit(RNDD(dst_reg(tmp), op[0]));
1510       tmp.negate = true;
1511       inst = emit(MOV(dst, tmp));
1512       inst->saturate = instr->dest.saturate;
1513       break;
1514    }
1515 
1516    case nir_op_ffloor:
1517       inst = emit(RNDD(dst, op[0]));
1518       inst->saturate = instr->dest.saturate;
1519       break;
1520 
1521    case nir_op_ffract:
1522       inst = emit(FRC(dst, op[0]));
1523       inst->saturate = instr->dest.saturate;
1524       break;
1525 
1526    case nir_op_fround_even:
1527       inst = emit(RNDE(dst, op[0]));
1528       inst->saturate = instr->dest.saturate;
1529       break;
1530 
1531    case nir_op_fquantize2f16: {
1532       /* See also vec4_visitor::emit_pack_half_2x16() */
1533       src_reg tmp16 = src_reg(this, glsl_type::uvec4_type);
1534       src_reg tmp32 = src_reg(this, glsl_type::vec4_type);
1535       src_reg zero = src_reg(this, glsl_type::vec4_type);
1536 
1537       /* Check for denormal */
1538       src_reg abs_src0 = op[0];
1539       abs_src0.abs = true;
1540       emit(CMP(dst_null_f(), abs_src0, brw_imm_f(ldexpf(1.0, -14)),
1541                BRW_CONDITIONAL_L));
1542       /* Get the appropriately signed zero */
1543       emit(AND(retype(dst_reg(zero), BRW_REGISTER_TYPE_UD),
1544                retype(op[0], BRW_REGISTER_TYPE_UD),
1545                brw_imm_ud(0x80000000)));
1546       /* Do the actual F32 -> F16 -> F32 conversion */
1547       emit(F32TO16(dst_reg(tmp16), op[0]));
1548       emit(F16TO32(dst_reg(tmp32), tmp16));
1549       /* Select that or zero based on normal status */
1550       inst = emit(BRW_OPCODE_SEL, dst, zero, tmp32);
1551       inst->predicate = BRW_PREDICATE_NORMAL;
1552       inst->saturate = instr->dest.saturate;
1553       break;
1554    }
1555 
1556    case nir_op_imin:
1557    case nir_op_umin:
1558       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1559    case nir_op_fmin:
1560       inst = emit_minmax(BRW_CONDITIONAL_L, dst, op[0], op[1]);
1561       inst->saturate = instr->dest.saturate;
1562       break;
1563 
1564    case nir_op_imax:
1565    case nir_op_umax:
1566       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1567    case nir_op_fmax:
1568       inst = emit_minmax(BRW_CONDITIONAL_GE, dst, op[0], op[1]);
1569       inst->saturate = instr->dest.saturate;
1570       break;
1571 
1572    case nir_op_fddx:
1573    case nir_op_fddx_coarse:
1574    case nir_op_fddx_fine:
1575    case nir_op_fddy:
1576    case nir_op_fddy_coarse:
1577    case nir_op_fddy_fine:
1578       unreachable("derivatives are not valid in vertex shaders");
1579 
1580    case nir_op_ilt:
1581    case nir_op_ult:
1582    case nir_op_ige:
1583    case nir_op_uge:
1584    case nir_op_ieq:
1585    case nir_op_ine:
1586       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1587       /* Fallthrough */
1588    case nir_op_flt:
1589    case nir_op_fge:
1590    case nir_op_feq:
1591    case nir_op_fne: {
1592       enum brw_conditional_mod conditional_mod =
1593          brw_conditional_for_nir_comparison(instr->op);
1594 
1595       if (nir_src_bit_size(instr->src[0].src) < 64) {
1596          emit(CMP(dst, op[0], op[1], conditional_mod));
1597       } else {
1598          /* Produce a 32-bit boolean result from the DF comparison by selecting
1599           * only the low 32-bit in each DF produced. Do this in a temporary
1600           * so we can then move from there to the result using align16 again
1601           * to honor the original writemask.
1602           */
1603          dst_reg temp = dst_reg(this, glsl_type::dvec4_type);
1604          emit(CMP(temp, op[0], op[1], conditional_mod));
1605          dst_reg result = dst_reg(this, glsl_type::bvec4_type);
1606          emit(VEC4_OPCODE_PICK_LOW_32BIT, result, src_reg(temp));
1607          emit(MOV(dst, src_reg(result)));
1608       }
1609       break;
1610    }
1611 
1612    case nir_op_ball_iequal2:
1613    case nir_op_ball_iequal3:
1614    case nir_op_ball_iequal4:
1615       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1616       /* Fallthrough */
1617    case nir_op_ball_fequal2:
1618    case nir_op_ball_fequal3:
1619    case nir_op_ball_fequal4: {
1620       unsigned swiz =
1621          brw_swizzle_for_size(nir_op_infos[instr->op].input_sizes[0]);
1622 
1623       emit(CMP(dst_null_d(), swizzle(op[0], swiz), swizzle(op[1], swiz),
1624                brw_conditional_for_nir_comparison(instr->op)));
1625       emit(MOV(dst, brw_imm_d(0)));
1626       inst = emit(MOV(dst, brw_imm_d(~0)));
1627       inst->predicate = BRW_PREDICATE_ALIGN16_ALL4H;
1628       break;
1629    }
1630 
1631    case nir_op_bany_inequal2:
1632    case nir_op_bany_inequal3:
1633    case nir_op_bany_inequal4:
1634       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1635       /* Fallthrough */
1636    case nir_op_bany_fnequal2:
1637    case nir_op_bany_fnequal3:
1638    case nir_op_bany_fnequal4: {
1639       unsigned swiz =
1640          brw_swizzle_for_size(nir_op_infos[instr->op].input_sizes[0]);
1641 
1642       emit(CMP(dst_null_d(), swizzle(op[0], swiz), swizzle(op[1], swiz),
1643                brw_conditional_for_nir_comparison(instr->op)));
1644 
1645       emit(MOV(dst, brw_imm_d(0)));
1646       inst = emit(MOV(dst, brw_imm_d(~0)));
1647       inst->predicate = BRW_PREDICATE_ALIGN16_ANY4H;
1648       break;
1649    }
1650 
1651    case nir_op_inot:
1652       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1653       if (devinfo->gen >= 8) {
1654          op[0] = resolve_source_modifiers(op[0]);
1655       }
1656       emit(NOT(dst, op[0]));
1657       break;
1658 
1659    case nir_op_ixor:
1660       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1661       if (devinfo->gen >= 8) {
1662          op[0] = resolve_source_modifiers(op[0]);
1663          op[1] = resolve_source_modifiers(op[1]);
1664       }
1665       emit(XOR(dst, op[0], op[1]));
1666       break;
1667 
1668    case nir_op_ior:
1669       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1670       if (devinfo->gen >= 8) {
1671          op[0] = resolve_source_modifiers(op[0]);
1672          op[1] = resolve_source_modifiers(op[1]);
1673       }
1674       emit(OR(dst, op[0], op[1]));
1675       break;
1676 
1677    case nir_op_iand:
1678       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1679       if (devinfo->gen >= 8) {
1680          op[0] = resolve_source_modifiers(op[0]);
1681          op[1] = resolve_source_modifiers(op[1]);
1682       }
1683       emit(AND(dst, op[0], op[1]));
1684       break;
1685 
1686    case nir_op_b2i:
1687    case nir_op_b2f:
1688       emit(MOV(dst, negate(op[0])));
1689       break;
1690 
1691    case nir_op_f2b:
1692       emit(CMP(dst, op[0], brw_imm_f(0.0f), BRW_CONDITIONAL_NZ));
1693       break;
1694 
1695    case nir_op_d2b: {
1696       /* We use a MOV with conditional_mod to check if the provided value is
1697        * 0.0. We want this to flush denormalized numbers to zero, so we set a
1698        * source modifier on the source operand to trigger this, as source
1699        * modifiers don't affect the result of the testing against 0.0.
1700        */
1701       src_reg value = op[0];
1702       value.abs = true;
1703       vec4_instruction *inst = emit(MOV(dst_null_df(), value));
1704       inst->conditional_mod = BRW_CONDITIONAL_NZ;
1705 
1706       src_reg one = src_reg(this, glsl_type::ivec4_type);
1707       emit(MOV(dst_reg(one), brw_imm_d(~0)));
1708       inst = emit(BRW_OPCODE_SEL, dst, one, brw_imm_d(0));
1709       inst->predicate = BRW_PREDICATE_NORMAL;
1710       break;
1711    }
1712 
1713    case nir_op_i2b:
1714       emit(CMP(dst, op[0], brw_imm_d(0), BRW_CONDITIONAL_NZ));
1715       break;
1716 
1717    case nir_op_fnoise1_1:
1718    case nir_op_fnoise1_2:
1719    case nir_op_fnoise1_3:
1720    case nir_op_fnoise1_4:
1721    case nir_op_fnoise2_1:
1722    case nir_op_fnoise2_2:
1723    case nir_op_fnoise2_3:
1724    case nir_op_fnoise2_4:
1725    case nir_op_fnoise3_1:
1726    case nir_op_fnoise3_2:
1727    case nir_op_fnoise3_3:
1728    case nir_op_fnoise3_4:
1729    case nir_op_fnoise4_1:
1730    case nir_op_fnoise4_2:
1731    case nir_op_fnoise4_3:
1732    case nir_op_fnoise4_4:
1733       unreachable("not reached: should be handled by lower_noise");
1734 
1735    case nir_op_unpack_half_2x16_split_x:
1736    case nir_op_unpack_half_2x16_split_y:
1737    case nir_op_pack_half_2x16_split:
1738       unreachable("not reached: should not occur in vertex shader");
1739 
1740    case nir_op_unpack_snorm_2x16:
1741    case nir_op_unpack_unorm_2x16:
1742    case nir_op_pack_snorm_2x16:
1743    case nir_op_pack_unorm_2x16:
1744       unreachable("not reached: should be handled by lower_packing_builtins");
1745 
1746    case nir_op_pack_uvec4_to_uint:
1747       unreachable("not reached");
1748 
1749    case nir_op_pack_uvec2_to_uint: {
1750       dst_reg tmp1 = dst_reg(this, glsl_type::uint_type);
1751       tmp1.writemask = WRITEMASK_X;
1752       op[0].swizzle = BRW_SWIZZLE_YYYY;
1753       emit(SHL(tmp1, op[0], src_reg(brw_imm_ud(16u))));
1754 
1755       dst_reg tmp2 = dst_reg(this, glsl_type::uint_type);
1756       tmp2.writemask = WRITEMASK_X;
1757       op[0].swizzle = BRW_SWIZZLE_XXXX;
1758       emit(AND(tmp2, op[0], src_reg(brw_imm_ud(0xffffu))));
1759 
1760       emit(OR(dst, src_reg(tmp1), src_reg(tmp2)));
1761       break;
1762    }
1763 
1764    case nir_op_pack_double_2x32_split: {
1765       dst_reg result = dst_reg(this, glsl_type::dvec4_type);
1766       dst_reg tmp = dst_reg(this, glsl_type::uvec4_type);
1767       emit(MOV(tmp, retype(op[0], BRW_REGISTER_TYPE_UD)));
1768       emit(VEC4_OPCODE_SET_LOW_32BIT, result, src_reg(tmp));
1769       emit(MOV(tmp, retype(op[1], BRW_REGISTER_TYPE_UD)));
1770       emit(VEC4_OPCODE_SET_HIGH_32BIT, result, src_reg(tmp));
1771       emit(MOV(dst, src_reg(result)));
1772       break;
1773    }
1774 
1775    case nir_op_unpack_double_2x32_split_x:
1776    case nir_op_unpack_double_2x32_split_y: {
1777       enum opcode oper = (instr->op == nir_op_unpack_double_2x32_split_x) ?
1778          VEC4_OPCODE_PICK_LOW_32BIT : VEC4_OPCODE_PICK_HIGH_32BIT;
1779       dst_reg tmp = dst_reg(this, glsl_type::dvec4_type);
1780       emit(MOV(tmp, op[0]));
1781       dst_reg tmp2 = dst_reg(this, glsl_type::uvec4_type);
1782       emit(oper, tmp2, src_reg(tmp));
1783       emit(MOV(dst, src_reg(tmp2)));
1784       break;
1785    }
1786 
1787    case nir_op_unpack_half_2x16:
1788       /* As NIR does not guarantee that we have a correct swizzle outside the
1789        * boundaries of a vector, and the implementation of emit_unpack_half_2x16
1790        * uses the source operand in an operation with WRITEMASK_Y while our
1791        * source operand has only size 1, it accessed incorrect data producing
1792        * regressions in Piglit. We repeat the swizzle of the first component on the
1793        * rest of components to avoid regressions. In the vec4_visitor IR code path
1794        * this is not needed because the operand has already the correct swizzle.
1795        */
1796       op[0].swizzle = brw_compose_swizzle(BRW_SWIZZLE_XXXX, op[0].swizzle);
1797       emit_unpack_half_2x16(dst, op[0]);
1798       break;
1799 
1800    case nir_op_pack_half_2x16:
1801       emit_pack_half_2x16(dst, op[0]);
1802       break;
1803 
1804    case nir_op_unpack_unorm_4x8:
1805       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1806       emit_unpack_unorm_4x8(dst, op[0]);
1807       break;
1808 
1809    case nir_op_pack_unorm_4x8:
1810       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1811       emit_pack_unorm_4x8(dst, op[0]);
1812       break;
1813 
1814    case nir_op_unpack_snorm_4x8:
1815       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1816       emit_unpack_snorm_4x8(dst, op[0]);
1817       break;
1818 
1819    case nir_op_pack_snorm_4x8:
1820       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1821       emit_pack_snorm_4x8(dst, op[0]);
1822       break;
1823 
1824    case nir_op_bitfield_reverse:
1825       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1826       emit(BFREV(dst, op[0]));
1827       break;
1828 
1829    case nir_op_bit_count:
1830       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1831       emit(CBIT(dst, op[0]));
1832       break;
1833 
1834    case nir_op_ufind_msb:
1835       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1836       emit_find_msb_using_lzd(vec4_builder(this).at_end(), dst, op[0], false);
1837       break;
1838 
1839    case nir_op_ifind_msb: {
1840       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1841       vec4_builder bld = vec4_builder(this).at_end();
1842       src_reg src(dst);
1843 
1844       if (devinfo->gen < 7) {
1845          emit_find_msb_using_lzd(bld, dst, op[0], true);
1846       } else {
1847          emit(FBH(retype(dst, BRW_REGISTER_TYPE_UD), op[0]));
1848 
1849          /* FBH counts from the MSB side, while GLSL's findMSB() wants the
1850           * count from the LSB side. If FBH didn't return an error
1851           * (0xFFFFFFFF), then subtract the result from 31 to convert the MSB
1852           * count into an LSB count.
1853           */
1854          bld.CMP(dst_null_d(), src, brw_imm_d(-1), BRW_CONDITIONAL_NZ);
1855 
1856          inst = bld.ADD(dst, src, brw_imm_d(31));
1857          inst->predicate = BRW_PREDICATE_NORMAL;
1858          inst->src[0].negate = true;
1859       }
1860       break;
1861    }
1862 
1863    case nir_op_find_lsb: {
1864       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1865       vec4_builder bld = vec4_builder(this).at_end();
1866 
1867       if (devinfo->gen < 7) {
1868          dst_reg temp = bld.vgrf(BRW_REGISTER_TYPE_D);
1869 
1870          /* (x & -x) generates a value that consists of only the LSB of x.
1871           * For all powers of 2, findMSB(y) == findLSB(y).
1872           */
1873          src_reg src = src_reg(retype(op[0], BRW_REGISTER_TYPE_D));
1874          src_reg negated_src = src;
1875 
1876          /* One must be negated, and the other must be non-negated.  It
1877           * doesn't matter which is which.
1878           */
1879          negated_src.negate = true;
1880          src.negate = false;
1881 
1882          bld.AND(temp, src, negated_src);
1883          emit_find_msb_using_lzd(bld, dst, src_reg(temp), false);
1884       } else {
1885          bld.FBL(dst, op[0]);
1886       }
1887       break;
1888    }
1889 
1890    case nir_op_ubitfield_extract:
1891    case nir_op_ibitfield_extract:
1892       unreachable("should have been lowered");
1893    case nir_op_ubfe:
1894    case nir_op_ibfe:
1895       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1896       op[0] = fix_3src_operand(op[0]);
1897       op[1] = fix_3src_operand(op[1]);
1898       op[2] = fix_3src_operand(op[2]);
1899 
1900       emit(BFE(dst, op[2], op[1], op[0]));
1901       break;
1902 
1903    case nir_op_bfm:
1904       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1905       emit(BFI1(dst, op[0], op[1]));
1906       break;
1907 
1908    case nir_op_bfi:
1909       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1910       op[0] = fix_3src_operand(op[0]);
1911       op[1] = fix_3src_operand(op[1]);
1912       op[2] = fix_3src_operand(op[2]);
1913 
1914       emit(BFI2(dst, op[0], op[1], op[2]));
1915       break;
1916 
1917    case nir_op_bitfield_insert:
1918       unreachable("not reached: should have been lowered");
1919 
1920    case nir_op_fsign:
1921       if (type_sz(op[0].type) < 8) {
1922          /* AND(val, 0x80000000) gives the sign bit.
1923           *
1924           * Predicated OR ORs 1.0 (0x3f800000) with the sign bit if val is not
1925           * zero.
1926           */
1927          emit(CMP(dst_null_f(), op[0], brw_imm_f(0.0f), BRW_CONDITIONAL_NZ));
1928 
1929          op[0].type = BRW_REGISTER_TYPE_UD;
1930          dst.type = BRW_REGISTER_TYPE_UD;
1931          emit(AND(dst, op[0], brw_imm_ud(0x80000000u)));
1932 
1933          inst = emit(OR(dst, src_reg(dst), brw_imm_ud(0x3f800000u)));
1934          inst->predicate = BRW_PREDICATE_NORMAL;
1935          dst.type = BRW_REGISTER_TYPE_F;
1936 
1937          if (instr->dest.saturate) {
1938             inst = emit(MOV(dst, src_reg(dst)));
1939             inst->saturate = true;
1940          }
1941       } else {
1942          /* For doubles we do the same but we need to consider:
1943           *
1944           * - We use a MOV with conditional_mod instead of a CMP so that we can
1945           *   skip loading a 0.0 immediate. We use a source modifier on the
1946           *   source of the MOV so that we flush denormalized values to 0.
1947           *   Since we want to compare against 0, this won't alter the result.
1948           * - We need to extract the high 32-bit of each DF where the sign
1949           *   is stored.
1950           * - We need to produce a DF result.
1951           */
1952 
1953          /* Check for zero */
1954          src_reg value = op[0];
1955          value.abs = true;
1956          inst = emit(MOV(dst_null_df(), value));
1957          inst->conditional_mod = BRW_CONDITIONAL_NZ;
1958 
1959          /* AND each high 32-bit channel with 0x80000000u */
1960          dst_reg tmp = dst_reg(this, glsl_type::uvec4_type);
1961          emit(VEC4_OPCODE_PICK_HIGH_32BIT, tmp, op[0]);
1962          emit(AND(tmp, src_reg(tmp), brw_imm_ud(0x80000000u)));
1963 
1964          /* Add 1.0 to each channel, predicated to skip the cases where the
1965           * channel's value was 0
1966           */
1967          inst = emit(OR(tmp, src_reg(tmp), brw_imm_ud(0x3f800000u)));
1968          inst->predicate = BRW_PREDICATE_NORMAL;
1969 
1970          /* Now convert the result from float to double */
1971          emit_conversion_to_double(dst, src_reg(tmp), instr->dest.saturate,
1972                                    BRW_REGISTER_TYPE_F);
1973       }
1974       break;
1975 
1976    case nir_op_isign:
1977       /*  ASR(val, 31) -> negative val generates 0xffffffff (signed -1).
1978        *               -> non-negative val generates 0x00000000.
1979        *  Predicated OR sets 1 if val is positive.
1980        */
1981       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1982       emit(CMP(dst_null_d(), op[0], brw_imm_d(0), BRW_CONDITIONAL_G));
1983       emit(ASR(dst, op[0], brw_imm_d(31)));
1984       inst = emit(OR(dst, src_reg(dst), brw_imm_d(1)));
1985       inst->predicate = BRW_PREDICATE_NORMAL;
1986       break;
1987 
1988    case nir_op_ishl:
1989       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1990       emit(SHL(dst, op[0], op[1]));
1991       break;
1992 
1993    case nir_op_ishr:
1994       assert(nir_dest_bit_size(instr->dest.dest) < 64);
1995       emit(ASR(dst, op[0], op[1]));
1996       break;
1997 
1998    case nir_op_ushr:
1999       assert(nir_dest_bit_size(instr->dest.dest) < 64);
2000       emit(SHR(dst, op[0], op[1]));
2001       break;
2002 
2003    case nir_op_ffma:
2004       if (type_sz(dst.type) == 8) {
2005          dst_reg mul_dst = dst_reg(this, glsl_type::dvec4_type);
2006          emit(MUL(mul_dst, op[1], op[0]));
2007          inst = emit(ADD(dst, src_reg(mul_dst), op[2]));
2008          inst->saturate = instr->dest.saturate;
2009       } else {
2010          op[0] = fix_3src_operand(op[0]);
2011          op[1] = fix_3src_operand(op[1]);
2012          op[2] = fix_3src_operand(op[2]);
2013 
2014          inst = emit(MAD(dst, op[2], op[1], op[0]));
2015          inst->saturate = instr->dest.saturate;
2016       }
2017       break;
2018 
2019    case nir_op_flrp:
2020       inst = emit_lrp(dst, op[0], op[1], op[2]);
2021       inst->saturate = instr->dest.saturate;
2022       break;
2023 
2024    case nir_op_bcsel:
2025       enum brw_predicate predicate;
2026       if (!optimize_predicate(instr, &predicate)) {
2027          emit(CMP(dst_null_d(), op[0], brw_imm_d(0), BRW_CONDITIONAL_NZ));
2028          switch (dst.writemask) {
2029          case WRITEMASK_X:
2030             predicate = BRW_PREDICATE_ALIGN16_REPLICATE_X;
2031             break;
2032          case WRITEMASK_Y:
2033             predicate = BRW_PREDICATE_ALIGN16_REPLICATE_Y;
2034             break;
2035          case WRITEMASK_Z:
2036             predicate = BRW_PREDICATE_ALIGN16_REPLICATE_Z;
2037             break;
2038          case WRITEMASK_W:
2039             predicate = BRW_PREDICATE_ALIGN16_REPLICATE_W;
2040             break;
2041          default:
2042             predicate = BRW_PREDICATE_NORMAL;
2043             break;
2044          }
2045       }
2046       inst = emit(BRW_OPCODE_SEL, dst, op[1], op[2]);
2047       inst->predicate = predicate;
2048       break;
2049 
2050    case nir_op_fdot_replicated2:
2051       inst = emit(BRW_OPCODE_DP2, dst, op[0], op[1]);
2052       inst->saturate = instr->dest.saturate;
2053       break;
2054 
2055    case nir_op_fdot_replicated3:
2056       inst = emit(BRW_OPCODE_DP3, dst, op[0], op[1]);
2057       inst->saturate = instr->dest.saturate;
2058       break;
2059 
2060    case nir_op_fdot_replicated4:
2061       inst = emit(BRW_OPCODE_DP4, dst, op[0], op[1]);
2062       inst->saturate = instr->dest.saturate;
2063       break;
2064 
2065    case nir_op_fdph_replicated:
2066       inst = emit(BRW_OPCODE_DPH, dst, op[0], op[1]);
2067       inst->saturate = instr->dest.saturate;
2068       break;
2069 
2070    case nir_op_iabs:
2071    case nir_op_ineg:
2072       assert(nir_dest_bit_size(instr->dest.dest) < 64);
2073    case nir_op_fabs:
2074    case nir_op_fneg:
2075    case nir_op_fsat:
2076       unreachable("not reached: should be lowered by lower_source mods");
2077 
2078    case nir_op_fdiv:
2079       unreachable("not reached: should be lowered by DIV_TO_MUL_RCP in the compiler");
2080 
2081    case nir_op_fmod:
2082       unreachable("not reached: should be lowered by MOD_TO_FLOOR in the compiler");
2083 
2084    case nir_op_fsub:
2085    case nir_op_isub:
2086       unreachable("not reached: should be handled by ir_sub_to_add_neg");
2087 
2088    default:
2089       unreachable("Unimplemented ALU operation");
2090    }
2091 
2092    /* If we need to do a boolean resolve, replace the result with -(x & 1)
2093     * to sign extend the low bit to 0/~0
2094     */
2095    if (devinfo->gen <= 5 &&
2096        (instr->instr.pass_flags & BRW_NIR_BOOLEAN_MASK) ==
2097        BRW_NIR_BOOLEAN_NEEDS_RESOLVE) {
2098       dst_reg masked = dst_reg(this, glsl_type::int_type);
2099       masked.writemask = dst.writemask;
2100       emit(AND(masked, src_reg(dst), brw_imm_d(1)));
2101       src_reg masked_neg = src_reg(masked);
2102       masked_neg.negate = true;
2103       emit(MOV(retype(dst, BRW_REGISTER_TYPE_D), masked_neg));
2104    }
2105 }
2106 
2107 void
nir_emit_jump(nir_jump_instr * instr)2108 vec4_visitor::nir_emit_jump(nir_jump_instr *instr)
2109 {
2110    switch (instr->type) {
2111    case nir_jump_break:
2112       emit(BRW_OPCODE_BREAK);
2113       break;
2114 
2115    case nir_jump_continue:
2116       emit(BRW_OPCODE_CONTINUE);
2117       break;
2118 
2119    case nir_jump_return:
2120       /* fall through */
2121    default:
2122       unreachable("unknown jump");
2123    }
2124 }
2125 
2126 enum ir_texture_opcode
ir_texture_opcode_for_nir_texop(nir_texop texop)2127 ir_texture_opcode_for_nir_texop(nir_texop texop)
2128 {
2129    enum ir_texture_opcode op;
2130 
2131    switch (texop) {
2132    case nir_texop_lod: op = ir_lod; break;
2133    case nir_texop_query_levels: op = ir_query_levels; break;
2134    case nir_texop_texture_samples: op = ir_texture_samples; break;
2135    case nir_texop_tex: op = ir_tex; break;
2136    case nir_texop_tg4: op = ir_tg4; break;
2137    case nir_texop_txb: op = ir_txb; break;
2138    case nir_texop_txd: op = ir_txd; break;
2139    case nir_texop_txf: op = ir_txf; break;
2140    case nir_texop_txf_ms: op = ir_txf_ms; break;
2141    case nir_texop_txl: op = ir_txl; break;
2142    case nir_texop_txs: op = ir_txs; break;
2143    case nir_texop_samples_identical: op = ir_samples_identical; break;
2144    default:
2145       unreachable("unknown texture opcode");
2146    }
2147 
2148    return op;
2149 }
2150 const glsl_type *
glsl_type_for_nir_alu_type(nir_alu_type alu_type,unsigned components)2151 glsl_type_for_nir_alu_type(nir_alu_type alu_type,
2152                            unsigned components)
2153 {
2154    return glsl_type::get_instance(brw_glsl_base_type_for_nir_type(alu_type),
2155                                   components, 1);
2156 }
2157 
2158 void
nir_emit_texture(nir_tex_instr * instr)2159 vec4_visitor::nir_emit_texture(nir_tex_instr *instr)
2160 {
2161    unsigned texture = instr->texture_index;
2162    unsigned sampler = instr->sampler_index;
2163    src_reg texture_reg = brw_imm_ud(texture);
2164    src_reg sampler_reg = brw_imm_ud(sampler);
2165    src_reg coordinate;
2166    const glsl_type *coord_type = NULL;
2167    src_reg shadow_comparator;
2168    src_reg offset_value;
2169    src_reg lod, lod2;
2170    src_reg sample_index;
2171    src_reg mcs;
2172 
2173    const glsl_type *dest_type =
2174       glsl_type_for_nir_alu_type(instr->dest_type,
2175                                  nir_tex_instr_dest_size(instr));
2176    dst_reg dest = get_nir_dest(instr->dest, instr->dest_type);
2177 
2178    /* The hardware requires a LOD for buffer textures */
2179    if (instr->sampler_dim == GLSL_SAMPLER_DIM_BUF)
2180       lod = brw_imm_d(0);
2181 
2182    /* Load the texture operation sources */
2183    uint32_t constant_offset = 0;
2184    for (unsigned i = 0; i < instr->num_srcs; i++) {
2185       switch (instr->src[i].src_type) {
2186       case nir_tex_src_comparator:
2187          shadow_comparator = get_nir_src(instr->src[i].src,
2188                                          BRW_REGISTER_TYPE_F, 1);
2189          break;
2190 
2191       case nir_tex_src_coord: {
2192          unsigned src_size = nir_tex_instr_src_size(instr, i);
2193 
2194          switch (instr->op) {
2195          case nir_texop_txf:
2196          case nir_texop_txf_ms:
2197          case nir_texop_samples_identical:
2198             coordinate = get_nir_src(instr->src[i].src, BRW_REGISTER_TYPE_D,
2199                                      src_size);
2200             coord_type = glsl_type::ivec(src_size);
2201             break;
2202 
2203          default:
2204             coordinate = get_nir_src(instr->src[i].src, BRW_REGISTER_TYPE_F,
2205                                      src_size);
2206             coord_type = glsl_type::vec(src_size);
2207             break;
2208          }
2209          break;
2210       }
2211 
2212       case nir_tex_src_ddx:
2213          lod = get_nir_src(instr->src[i].src, BRW_REGISTER_TYPE_F,
2214                            nir_tex_instr_src_size(instr, i));
2215          break;
2216 
2217       case nir_tex_src_ddy:
2218          lod2 = get_nir_src(instr->src[i].src, BRW_REGISTER_TYPE_F,
2219                            nir_tex_instr_src_size(instr, i));
2220          break;
2221 
2222       case nir_tex_src_lod:
2223          switch (instr->op) {
2224          case nir_texop_txs:
2225          case nir_texop_txf:
2226             lod = get_nir_src(instr->src[i].src, BRW_REGISTER_TYPE_D, 1);
2227             break;
2228 
2229          default:
2230             lod = get_nir_src(instr->src[i].src, BRW_REGISTER_TYPE_F, 1);
2231             break;
2232          }
2233          break;
2234 
2235       case nir_tex_src_ms_index: {
2236          sample_index = get_nir_src(instr->src[i].src, BRW_REGISTER_TYPE_D, 1);
2237          break;
2238       }
2239 
2240       case nir_tex_src_offset: {
2241          nir_const_value *const_offset =
2242             nir_src_as_const_value(instr->src[i].src);
2243          if (!const_offset ||
2244              !brw_texture_offset(const_offset->i32,
2245                                  nir_tex_instr_src_size(instr, i),
2246                                  &constant_offset)) {
2247             offset_value =
2248                get_nir_src(instr->src[i].src, BRW_REGISTER_TYPE_D, 2);
2249          }
2250          break;
2251       }
2252 
2253       case nir_tex_src_texture_offset: {
2254          /* The highest texture which may be used by this operation is
2255           * the last element of the array. Mark it here, because the generator
2256           * doesn't have enough information to determine the bound.
2257           */
2258          uint32_t array_size = instr->texture_array_size;
2259          uint32_t max_used = texture + array_size - 1;
2260          if (instr->op == nir_texop_tg4) {
2261             max_used += prog_data->base.binding_table.gather_texture_start;
2262          } else {
2263             max_used += prog_data->base.binding_table.texture_start;
2264          }
2265 
2266          brw_mark_surface_used(&prog_data->base, max_used);
2267 
2268          /* Emit code to evaluate the actual indexing expression */
2269          src_reg src = get_nir_src(instr->src[i].src, 1);
2270          src_reg temp(this, glsl_type::uint_type);
2271          emit(ADD(dst_reg(temp), src, brw_imm_ud(texture)));
2272          texture_reg = emit_uniformize(temp);
2273          break;
2274       }
2275 
2276       case nir_tex_src_sampler_offset: {
2277          /* Emit code to evaluate the actual indexing expression */
2278          src_reg src = get_nir_src(instr->src[i].src, 1);
2279          src_reg temp(this, glsl_type::uint_type);
2280          emit(ADD(dst_reg(temp), src, brw_imm_ud(sampler)));
2281          sampler_reg = emit_uniformize(temp);
2282          break;
2283       }
2284 
2285       case nir_tex_src_projector:
2286          unreachable("Should be lowered by do_lower_texture_projection");
2287 
2288       case nir_tex_src_bias:
2289          unreachable("LOD bias is not valid for vertex shaders.\n");
2290 
2291       default:
2292          unreachable("unknown texture source");
2293       }
2294    }
2295 
2296    if (instr->op == nir_texop_txf_ms ||
2297        instr->op == nir_texop_samples_identical) {
2298       assert(coord_type != NULL);
2299       if (devinfo->gen >= 7 &&
2300           key_tex->compressed_multisample_layout_mask & (1 << texture)) {
2301          mcs = emit_mcs_fetch(coord_type, coordinate, texture_reg);
2302       } else {
2303          mcs = brw_imm_ud(0u);
2304       }
2305    }
2306 
2307    /* Stuff the channel select bits in the top of the texture offset */
2308    if (instr->op == nir_texop_tg4) {
2309       if (instr->component == 1 &&
2310           (key_tex->gather_channel_quirk_mask & (1 << texture))) {
2311          /* gather4 sampler is broken for green channel on RG32F --
2312           * we must ask for blue instead.
2313           */
2314          constant_offset |= 2 << 16;
2315       } else {
2316          constant_offset |= instr->component << 16;
2317       }
2318    }
2319 
2320    ir_texture_opcode op = ir_texture_opcode_for_nir_texop(instr->op);
2321 
2322    emit_texture(op, dest, dest_type, coordinate, instr->coord_components,
2323                 shadow_comparator,
2324                 lod, lod2, sample_index,
2325                 constant_offset, offset_value, mcs,
2326                 texture, texture_reg, sampler_reg);
2327 }
2328 
2329 void
nir_emit_undef(nir_ssa_undef_instr * instr)2330 vec4_visitor::nir_emit_undef(nir_ssa_undef_instr *instr)
2331 {
2332    nir_ssa_values[instr->def.index] =
2333       dst_reg(VGRF, alloc.allocate(DIV_ROUND_UP(instr->def.bit_size, 32)));
2334 }
2335 
2336 /* SIMD4x2 64bit data is stored in register space like this:
2337  *
2338  * r0.0:DF  x0 y0 z0 w0
2339  * r1.0:DF  x1 y1 z1 w1
2340  *
2341  * When we need to write data such as this to memory using 32-bit write
2342  * messages we need to shuffle it in this fashion:
2343  *
2344  * r0.0:DF  x0 y0 x1 y1 (to be written at base offset)
2345  * r0.0:DF  z0 w0 z1 w1 (to be written at base offset + 16)
2346  *
2347  * We need to do the inverse operation when we read using 32-bit messages,
2348  * which we can do by applying the same exact shuffling on the 64-bit data
2349  * read, only that because the data for each vertex is positioned differently
2350  * we need to apply different channel enables.
2351  *
2352  * This function takes 64bit data and shuffles it as explained above.
2353  *
2354  * The @for_write parameter is used to specify if the shuffling is being done
2355  * for proper SIMD4x2 64-bit data that needs to be shuffled prior to a 32-bit
2356  * write message (for_write = true), or instead we are doing the inverse
2357  * operation and we have just read 64-bit data using a 32-bit messages that we
2358  * need to shuffle to create valid SIMD4x2 64-bit data (for_write = false).
2359  *
2360  * If @block and @ref are non-NULL, then the shuffling is done after @ref,
2361  * otherwise the instructions are emitted normally at the end. The function
2362  * returns the last instruction inserted.
2363  *
2364  * Notice that @src and @dst cannot be the same register.
2365  */
2366 vec4_instruction *
shuffle_64bit_data(dst_reg dst,src_reg src,bool for_write,bblock_t * block,vec4_instruction * ref)2367 vec4_visitor::shuffle_64bit_data(dst_reg dst, src_reg src, bool for_write,
2368                                  bblock_t *block, vec4_instruction *ref)
2369 {
2370    assert(type_sz(src.type) == 8);
2371    assert(type_sz(dst.type) == 8);
2372    assert(!regions_overlap(dst, 2 * REG_SIZE, src, 2 * REG_SIZE));
2373    assert(!ref == !block);
2374 
2375    const vec4_builder bld = !ref ? vec4_builder(this).at_end() :
2376                                    vec4_builder(this).at(block, ref->next);
2377 
2378    /* Resolve swizzle in src */
2379    vec4_instruction *inst;
2380    if (src.swizzle != BRW_SWIZZLE_XYZW) {
2381       dst_reg data = dst_reg(this, glsl_type::dvec4_type);
2382       inst = bld.MOV(data, src);
2383       src = src_reg(data);
2384    }
2385 
2386    /* dst+0.XY = src+0.XY */
2387    inst = bld.group(4, 0).MOV(writemask(dst, WRITEMASK_XY), src);
2388 
2389    /* dst+0.ZW = src+1.XY */
2390    inst = bld.group(4, for_write ? 1 : 0)
2391              .MOV(writemask(dst, WRITEMASK_ZW),
2392                   swizzle(byte_offset(src, REG_SIZE), BRW_SWIZZLE_XYXY));
2393 
2394    /* dst+1.XY = src+0.ZW */
2395    inst = bld.group(4, for_write ? 0 : 1)
2396             .MOV(writemask(byte_offset(dst, REG_SIZE), WRITEMASK_XY),
2397                  swizzle(src, BRW_SWIZZLE_ZWZW));
2398 
2399    /* dst+1.ZW = src+1.ZW */
2400    inst = bld.group(4, 1)
2401              .MOV(writemask(byte_offset(dst, REG_SIZE), WRITEMASK_ZW),
2402                  byte_offset(src, REG_SIZE));
2403 
2404    return inst;
2405 }
2406 
2407 }
2408