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1 /*
2  * Copyright © 2014-2015 Broadcom
3  * Copyright © 2021 Google
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining a
6  * copy of this software and associated documentation files (the "Software"),
7  * to deal in the Software without restriction, including without limitation
8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9  * and/or sell copies of the Software, and to permit persons to whom the
10  * Software is furnished to do so, subject to the following conditions:
11  *
12  * The above copyright notice and this permission notice (including the next
13  * paragraph) shall be included in all copies or substantial portions of the
14  * Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
22  * IN THE SOFTWARE.
23  */
24 
25 #include "nir_builder.h"
26 
27 void
nir_builder_init(nir_builder * build,nir_function_impl * impl)28 nir_builder_init(nir_builder *build, nir_function_impl *impl)
29 {
30    memset(build, 0, sizeof(*build));
31    build->exact = false;
32    build->impl = impl;
33    build->shader = impl->function->shader;
34 }
35 
36 nir_builder MUST_CHECK PRINTFLIKE(3, 4)
nir_builder_init_simple_shader(gl_shader_stage stage,const nir_shader_compiler_options * options,const char * name,...)37 nir_builder_init_simple_shader(gl_shader_stage stage,
38                                const nir_shader_compiler_options *options,
39                                const char *name, ...)
40 {
41    nir_builder b;
42 
43    memset(&b, 0, sizeof(b));
44    b.shader = nir_shader_create(NULL, stage, options, NULL);
45 
46    if (name) {
47       va_list args;
48       va_start(args, name);
49       b.shader->info.name = ralloc_vasprintf(b.shader, name, args);
50       va_end(args);
51    }
52 
53    nir_function *func = nir_function_create(b.shader, "main");
54    func->is_entrypoint = true;
55    b.exact = false;
56    b.impl = nir_function_impl_create(func);
57    b.cursor = nir_after_cf_list(&b.impl->body);
58 
59    /* Simple shaders are typically internal, e.g. blit shaders */
60    b.shader->info.internal = true;
61 
62    return b;
63 }
64 
65 nir_ssa_def *
nir_builder_alu_instr_finish_and_insert(nir_builder * build,nir_alu_instr * instr)66 nir_builder_alu_instr_finish_and_insert(nir_builder *build, nir_alu_instr *instr)
67 {
68    const nir_op_info *op_info = &nir_op_infos[instr->op];
69 
70    instr->exact = build->exact;
71 
72    /* Guess the number of components the destination temporary should have
73     * based on our input sizes, if it's not fixed for the op.
74     */
75    unsigned num_components = op_info->output_size;
76    if (num_components == 0) {
77       for (unsigned i = 0; i < op_info->num_inputs; i++) {
78          if (op_info->input_sizes[i] == 0)
79             num_components = MAX2(num_components,
80                                   instr->src[i].src.ssa->num_components);
81       }
82    }
83    assert(num_components != 0);
84 
85    /* Figure out the bitwidth based on the source bitwidth if the instruction
86     * is variable-width.
87     */
88    unsigned bit_size = nir_alu_type_get_type_size(op_info->output_type);
89    if (bit_size == 0) {
90       for (unsigned i = 0; i < op_info->num_inputs; i++) {
91          unsigned src_bit_size = instr->src[i].src.ssa->bit_size;
92          if (nir_alu_type_get_type_size(op_info->input_types[i]) == 0) {
93             if (bit_size)
94                assert(src_bit_size == bit_size);
95             else
96                bit_size = src_bit_size;
97          } else {
98             assert(src_bit_size ==
99                nir_alu_type_get_type_size(op_info->input_types[i]));
100          }
101       }
102    }
103 
104    /* When in doubt, assume 32. */
105    if (bit_size == 0)
106       bit_size = 32;
107 
108    /* Make sure we don't swizzle from outside of our source vector (like if a
109     * scalar value was passed into a multiply with a vector).
110     */
111    for (unsigned i = 0; i < op_info->num_inputs; i++) {
112       for (unsigned j = instr->src[i].src.ssa->num_components;
113            j < NIR_MAX_VEC_COMPONENTS; j++) {
114          instr->src[i].swizzle[j] = instr->src[i].src.ssa->num_components - 1;
115       }
116    }
117 
118    nir_ssa_dest_init(&instr->instr, &instr->dest.dest, num_components,
119                      bit_size, NULL);
120    instr->dest.write_mask = (1 << num_components) - 1;
121 
122    nir_builder_instr_insert(build, &instr->instr);
123 
124    return &instr->dest.dest.ssa;
125 }
126 
127 nir_ssa_def *
nir_build_alu(nir_builder * build,nir_op op,nir_ssa_def * src0,nir_ssa_def * src1,nir_ssa_def * src2,nir_ssa_def * src3)128 nir_build_alu(nir_builder *build, nir_op op, nir_ssa_def *src0,
129               nir_ssa_def *src1, nir_ssa_def *src2, nir_ssa_def *src3)
130 {
131    nir_alu_instr *instr = nir_alu_instr_create(build->shader, op);
132    if (!instr)
133       return NULL;
134 
135    instr->src[0].src = nir_src_for_ssa(src0);
136    if (src1)
137       instr->src[1].src = nir_src_for_ssa(src1);
138    if (src2)
139       instr->src[2].src = nir_src_for_ssa(src2);
140    if (src3)
141       instr->src[3].src = nir_src_for_ssa(src3);
142 
143    return nir_builder_alu_instr_finish_and_insert(build, instr);
144 }
145 
146 nir_ssa_def *
nir_build_alu1(nir_builder * build,nir_op op,nir_ssa_def * src0)147 nir_build_alu1(nir_builder *build, nir_op op, nir_ssa_def *src0)
148 {
149    nir_alu_instr *instr = nir_alu_instr_create(build->shader, op);
150    if (!instr)
151       return NULL;
152 
153    instr->src[0].src = nir_src_for_ssa(src0);
154 
155    return nir_builder_alu_instr_finish_and_insert(build, instr);
156 }
157 
158 nir_ssa_def *
nir_build_alu2(nir_builder * build,nir_op op,nir_ssa_def * src0,nir_ssa_def * src1)159 nir_build_alu2(nir_builder *build, nir_op op, nir_ssa_def *src0,
160               nir_ssa_def *src1)
161 {
162    nir_alu_instr *instr = nir_alu_instr_create(build->shader, op);
163    if (!instr)
164       return NULL;
165 
166    instr->src[0].src = nir_src_for_ssa(src0);
167    instr->src[1].src = nir_src_for_ssa(src1);
168 
169    return nir_builder_alu_instr_finish_and_insert(build, instr);
170 }
171 
172 nir_ssa_def *
nir_build_alu3(nir_builder * build,nir_op op,nir_ssa_def * src0,nir_ssa_def * src1,nir_ssa_def * src2)173 nir_build_alu3(nir_builder *build, nir_op op, nir_ssa_def *src0,
174               nir_ssa_def *src1, nir_ssa_def *src2)
175 {
176    nir_alu_instr *instr = nir_alu_instr_create(build->shader, op);
177    if (!instr)
178       return NULL;
179 
180    instr->src[0].src = nir_src_for_ssa(src0);
181    instr->src[1].src = nir_src_for_ssa(src1);
182    instr->src[2].src = nir_src_for_ssa(src2);
183 
184    return nir_builder_alu_instr_finish_and_insert(build, instr);
185 }
186 
187 nir_ssa_def *
nir_build_alu4(nir_builder * build,nir_op op,nir_ssa_def * src0,nir_ssa_def * src1,nir_ssa_def * src2,nir_ssa_def * src3)188 nir_build_alu4(nir_builder *build, nir_op op, nir_ssa_def *src0,
189               nir_ssa_def *src1, nir_ssa_def *src2, nir_ssa_def *src3)
190 {
191    nir_alu_instr *instr = nir_alu_instr_create(build->shader, op);
192    if (!instr)
193       return NULL;
194 
195    instr->src[0].src = nir_src_for_ssa(src0);
196    instr->src[1].src = nir_src_for_ssa(src1);
197    instr->src[2].src = nir_src_for_ssa(src2);
198    instr->src[3].src = nir_src_for_ssa(src3);
199 
200    return nir_builder_alu_instr_finish_and_insert(build, instr);
201 }
202 
203 /* for the couple special cases with more than 4 src args: */
204 nir_ssa_def *
nir_build_alu_src_arr(nir_builder * build,nir_op op,nir_ssa_def ** srcs)205 nir_build_alu_src_arr(nir_builder *build, nir_op op, nir_ssa_def **srcs)
206 {
207    const nir_op_info *op_info = &nir_op_infos[op];
208    nir_alu_instr *instr = nir_alu_instr_create(build->shader, op);
209    if (!instr)
210       return NULL;
211 
212    for (unsigned i = 0; i < op_info->num_inputs; i++)
213       instr->src[i].src = nir_src_for_ssa(srcs[i]);
214 
215    return nir_builder_alu_instr_finish_and_insert(build, instr);
216 }
217 
218 nir_ssa_def *
nir_vec_scalars(nir_builder * build,nir_ssa_scalar * comp,unsigned num_components)219 nir_vec_scalars(nir_builder *build, nir_ssa_scalar *comp, unsigned num_components)
220 {
221    nir_op op = nir_op_vec(num_components);
222    nir_alu_instr *instr = nir_alu_instr_create(build->shader, op);
223    if (!instr)
224       return NULL;
225 
226    for (unsigned i = 0; i < num_components; i++) {
227       instr->src[i].src = nir_src_for_ssa(comp[i].def);
228       instr->src[i].swizzle[0] = comp[i].comp;
229    }
230    instr->exact = build->exact;
231 
232    /* Note: not reusing nir_builder_alu_instr_finish_and_insert() because it
233     * can't re-guess the num_components when num_components == 1 (nir_op_mov).
234     */
235    nir_ssa_dest_init(&instr->instr, &instr->dest.dest, num_components,
236                      comp[0].def->bit_size, NULL);
237    instr->dest.write_mask = (1 << num_components) - 1;
238 
239    nir_builder_instr_insert(build, &instr->instr);
240 
241    return &instr->dest.dest.ssa;
242 }
243 
244 /**
245  * Turns a nir_src into a nir_ssa_def * so it can be passed to
246  * nir_build_alu()-based builder calls.
247  *
248  * See nir_ssa_for_alu_src() for alu instructions.
249  */
250 nir_ssa_def *
nir_ssa_for_src(nir_builder * build,nir_src src,int num_components)251 nir_ssa_for_src(nir_builder *build, nir_src src, int num_components)
252 {
253    if (src.is_ssa && src.ssa->num_components == num_components)
254       return src.ssa;
255 
256    assert((unsigned)num_components <= nir_src_num_components(src));
257 
258    nir_alu_src alu = { NIR_SRC_INIT };
259    alu.src = src;
260    for (int j = 0; j < NIR_MAX_VEC_COMPONENTS; j++)
261       alu.swizzle[j] = j;
262 
263    return nir_mov_alu(build, alu, num_components);
264 }
265 
266 /**
267  * Similar to nir_ssa_for_src(), but for alu srcs, respecting the
268  * nir_alu_src's swizzle.
269  */
270 nir_ssa_def *
nir_ssa_for_alu_src(nir_builder * build,nir_alu_instr * instr,unsigned srcn)271 nir_ssa_for_alu_src(nir_builder *build, nir_alu_instr *instr, unsigned srcn)
272 {
273    if (nir_alu_src_is_trivial_ssa(instr, srcn))
274       return instr->src[srcn].src.ssa;
275 
276    nir_alu_src *src = &instr->src[srcn];
277    unsigned num_components = nir_ssa_alu_instr_src_components(instr, srcn);
278    return nir_mov_alu(build, *src, num_components);
279 }
280 
281 /* Generic builder for system values. */
282 nir_ssa_def *
nir_load_system_value(nir_builder * build,nir_intrinsic_op op,int index,unsigned num_components,unsigned bit_size)283 nir_load_system_value(nir_builder *build, nir_intrinsic_op op, int index,
284                       unsigned num_components, unsigned bit_size)
285 {
286    nir_intrinsic_instr *load = nir_intrinsic_instr_create(build->shader, op);
287    if (nir_intrinsic_infos[op].dest_components > 0)
288       assert(num_components == nir_intrinsic_infos[op].dest_components);
289    else
290       load->num_components = num_components;
291    load->const_index[0] = index;
292 
293    nir_ssa_dest_init(&load->instr, &load->dest,
294                      num_components, bit_size, NULL);
295    nir_builder_instr_insert(build, &load->instr);
296    return &load->dest.ssa;
297 }
298 
299 void
nir_builder_instr_insert(nir_builder * build,nir_instr * instr)300 nir_builder_instr_insert(nir_builder *build, nir_instr *instr)
301 {
302    nir_instr_insert(build->cursor, instr);
303 
304    if (build->update_divergence)
305       nir_update_instr_divergence(build->shader, instr);
306 
307    /* Move the cursor forward. */
308    build->cursor = nir_after_instr(instr);
309 }
310 
311 void
nir_builder_cf_insert(nir_builder * build,nir_cf_node * cf)312 nir_builder_cf_insert(nir_builder *build, nir_cf_node *cf)
313 {
314    nir_cf_node_insert(build->cursor, cf);
315 }
316 
317 bool
nir_builder_is_inside_cf(nir_builder * build,nir_cf_node * cf_node)318 nir_builder_is_inside_cf(nir_builder *build, nir_cf_node *cf_node)
319 {
320    nir_block *block = nir_cursor_current_block(build->cursor);
321    for (nir_cf_node *n = &block->cf_node; n; n = n->parent) {
322       if (n == cf_node)
323          return true;
324    }
325    return false;
326 }
327 
328 nir_if *
nir_push_if_src(nir_builder * build,nir_src condition)329 nir_push_if_src(nir_builder *build, nir_src condition)
330 {
331    nir_if *nif = nir_if_create(build->shader);
332    nif->condition = condition;
333    nir_builder_cf_insert(build, &nif->cf_node);
334    build->cursor = nir_before_cf_list(&nif->then_list);
335    return nif;
336 }
337 
338 nir_if *
nir_push_if(nir_builder * build,nir_ssa_def * condition)339 nir_push_if(nir_builder *build, nir_ssa_def *condition)
340 {
341    return nir_push_if_src(build, nir_src_for_ssa(condition));
342 }
343 
344 nir_if *
nir_push_else(nir_builder * build,nir_if * nif)345 nir_push_else(nir_builder *build, nir_if *nif)
346 {
347    if (nif) {
348       assert(nir_builder_is_inside_cf(build, &nif->cf_node));
349    } else {
350       nir_block *block = nir_cursor_current_block(build->cursor);
351       nif = nir_cf_node_as_if(block->cf_node.parent);
352    }
353    build->cursor = nir_before_cf_list(&nif->else_list);
354    return nif;
355 }
356 
357 void
nir_pop_if(nir_builder * build,nir_if * nif)358 nir_pop_if(nir_builder *build, nir_if *nif)
359 {
360    if (nif) {
361       assert(nir_builder_is_inside_cf(build, &nif->cf_node));
362    } else {
363       nir_block *block = nir_cursor_current_block(build->cursor);
364       nif = nir_cf_node_as_if(block->cf_node.parent);
365    }
366    build->cursor = nir_after_cf_node(&nif->cf_node);
367 }
368 
369 nir_ssa_def *
nir_if_phi(nir_builder * build,nir_ssa_def * then_def,nir_ssa_def * else_def)370 nir_if_phi(nir_builder *build, nir_ssa_def *then_def, nir_ssa_def *else_def)
371 {
372    nir_block *block = nir_cursor_current_block(build->cursor);
373    nir_if *nif = nir_cf_node_as_if(nir_cf_node_prev(&block->cf_node));
374 
375    nir_phi_instr *phi = nir_phi_instr_create(build->shader);
376    nir_phi_instr_add_src(phi, nir_if_last_then_block(nif), nir_src_for_ssa(then_def));
377    nir_phi_instr_add_src(phi, nir_if_last_else_block(nif), nir_src_for_ssa(else_def));
378 
379    assert(then_def->num_components == else_def->num_components);
380    assert(then_def->bit_size == else_def->bit_size);
381    nir_ssa_dest_init(&phi->instr, &phi->dest,
382                      then_def->num_components, then_def->bit_size, NULL);
383 
384    nir_builder_instr_insert(build, &phi->instr);
385 
386    return &phi->dest.ssa;
387 }
388 
389 nir_loop *
nir_push_loop(nir_builder * build)390 nir_push_loop(nir_builder *build)
391 {
392    nir_loop *loop = nir_loop_create(build->shader);
393    nir_builder_cf_insert(build, &loop->cf_node);
394    build->cursor = nir_before_cf_list(&loop->body);
395    return loop;
396 }
397 
398 void
nir_pop_loop(nir_builder * build,nir_loop * loop)399 nir_pop_loop(nir_builder *build, nir_loop *loop)
400 {
401    if (loop) {
402       assert(nir_builder_is_inside_cf(build, &loop->cf_node));
403    } else {
404       nir_block *block = nir_cursor_current_block(build->cursor);
405       loop = nir_cf_node_as_loop(block->cf_node.parent);
406    }
407    build->cursor = nir_after_cf_node(&loop->cf_node);
408 }
409 
410 nir_ssa_def *
nir_compare_func(nir_builder * b,enum compare_func func,nir_ssa_def * src0,nir_ssa_def * src1)411 nir_compare_func(nir_builder *b, enum compare_func func,
412                  nir_ssa_def *src0, nir_ssa_def *src1)
413 {
414    switch (func) {
415    case COMPARE_FUNC_NEVER:
416       return nir_imm_int(b, 0);
417    case COMPARE_FUNC_ALWAYS:
418       return nir_imm_int(b, ~0);
419    case COMPARE_FUNC_EQUAL:
420       return nir_feq(b, src0, src1);
421    case COMPARE_FUNC_NOTEQUAL:
422       return nir_fneu(b, src0, src1);
423    case COMPARE_FUNC_GREATER:
424       return nir_flt(b, src1, src0);
425    case COMPARE_FUNC_GEQUAL:
426       return nir_fge(b, src0, src1);
427    case COMPARE_FUNC_LESS:
428       return nir_flt(b, src0, src1);
429    case COMPARE_FUNC_LEQUAL:
430       return nir_fge(b, src1, src0);
431    }
432    unreachable("bad compare func");
433 }
434 
435 nir_ssa_def *
nir_type_convert(nir_builder * b,nir_ssa_def * src,nir_alu_type src_type,nir_alu_type dest_type)436 nir_type_convert(nir_builder *b,
437                     nir_ssa_def *src,
438                     nir_alu_type src_type,
439                     nir_alu_type dest_type)
440 {
441    assert(nir_alu_type_get_type_size(src_type) == 0 ||
442           nir_alu_type_get_type_size(src_type) == src->bit_size);
443 
444    src_type = (nir_alu_type) (src_type | src->bit_size);
445 
446    nir_op opcode =
447       nir_type_conversion_op(src_type, dest_type, nir_rounding_mode_undef);
448 
449    return nir_build_alu(b, opcode, src, NULL, NULL, NULL);
450 }
451 
452 nir_ssa_def *
nir_gen_rect_vertices(nir_builder * b,nir_ssa_def * z,nir_ssa_def * w)453 nir_gen_rect_vertices(nir_builder *b, nir_ssa_def *z, nir_ssa_def *w)
454 {
455    if (!z)
456       z = nir_imm_float(b, 0.0);
457    if (!w)
458       w = nir_imm_float(b, 1.0);
459 
460    nir_ssa_def *vertex_id;
461    if (b->shader->options->vertex_id_zero_based)
462       vertex_id = nir_load_vertex_id_zero_base(b);
463    else
464       vertex_id = nir_load_vertex_id(b);
465 
466    /* vertex 0: -1.0, -1.0
467     * vertex 1: -1.0,  1.0
468     * vertex 2:  1.0, -1.0
469     * vertex 3:  1.0,  1.0
470     *
471     * so:
472     *
473     * channel 0 is vertex_id < 2 ? -1.0 :  1.0
474     * channel 1 is vertex_id & 1 ?  1.0 : -1.0
475     */
476 
477    nir_ssa_def *c0cmp = nir_ilt(b, vertex_id, nir_imm_int(b, 2));
478    nir_ssa_def *c1cmp = nir_test_mask(b, vertex_id, 1);
479 
480    nir_ssa_def *comp[4];
481    comp[0] = nir_bcsel(b, c0cmp, nir_imm_float(b, -1.0), nir_imm_float(b, 1.0));
482    comp[1] = nir_bcsel(b, c1cmp, nir_imm_float(b, 1.0), nir_imm_float(b, -1.0));
483    comp[2] = z;
484    comp[3] = w;
485 
486    return nir_vec(b, comp, 4);
487 }
488