1/*
2 * Copyright © 2018 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 "nir.h"
25#include "nir_builder.h"
26#include "nir_deref.h"
27#include "util/hash_table.h"
28
29static bool
30is_trivial_deref_cast(nir_deref_instr *cast)
31{
32   nir_deref_instr *parent = nir_src_as_deref(cast->parent);
33   if (!parent)
34      return false;
35
36   return cast->modes == parent->modes &&
37          cast->type == parent->type &&
38          cast->dest.ssa.num_components == parent->dest.ssa.num_components &&
39          cast->dest.ssa.bit_size == parent->dest.ssa.bit_size;
40}
41
42void
43nir_deref_path_init(nir_deref_path *path,
44                    nir_deref_instr *deref, void *mem_ctx)
45{
46   assert(deref != NULL);
47
48   /* The length of the short path is at most ARRAY_SIZE - 1 because we need
49    * room for the NULL terminator.
50    */
51   static const int max_short_path_len = ARRAY_SIZE(path->_short_path) - 1;
52
53   int count = 0;
54
55   nir_deref_instr **tail = &path->_short_path[max_short_path_len];
56   nir_deref_instr **head = tail;
57
58   *tail = NULL;
59   for (nir_deref_instr *d = deref; d; d = nir_deref_instr_parent(d)) {
60      if (d->deref_type == nir_deref_type_cast && is_trivial_deref_cast(d))
61         continue;
62      count++;
63      if (count <= max_short_path_len)
64         *(--head) = d;
65   }
66
67   if (count <= max_short_path_len) {
68      /* If we're under max_short_path_len, just use the short path. */
69      path->path = head;
70      goto done;
71   }
72
73#ifndef NDEBUG
74   /* Just in case someone uses short_path by accident */
75   for (unsigned i = 0; i < ARRAY_SIZE(path->_short_path); i++)
76      path->_short_path[i] = (void *)(uintptr_t)0xdeadbeef;
77#endif
78
79   path->path = ralloc_array(mem_ctx, nir_deref_instr *, count + 1);
80   head = tail = path->path + count;
81   *tail = NULL;
82   for (nir_deref_instr *d = deref; d; d = nir_deref_instr_parent(d)) {
83      if (d->deref_type == nir_deref_type_cast && is_trivial_deref_cast(d))
84         continue;
85      *(--head) = d;
86   }
87
88done:
89   assert(head == path->path);
90   assert(tail == head + count);
91   assert(*tail == NULL);
92}
93
94void
95nir_deref_path_finish(nir_deref_path *path)
96{
97   if (path->path < &path->_short_path[0] ||
98       path->path > &path->_short_path[ARRAY_SIZE(path->_short_path) - 1])
99      ralloc_free(path->path);
100}
101
102/**
103 * Recursively removes unused deref instructions
104 */
105bool
106nir_deref_instr_remove_if_unused(nir_deref_instr *instr)
107{
108   bool progress = false;
109
110   for (nir_deref_instr *d = instr; d; d = nir_deref_instr_parent(d)) {
111      /* If anyone is using this deref, leave it alone */
112      assert(d->dest.is_ssa);
113      if (!nir_ssa_def_is_unused(&d->dest.ssa))
114         break;
115
116      nir_instr_remove(&d->instr);
117      progress = true;
118   }
119
120   return progress;
121}
122
123bool
124nir_deref_instr_has_indirect(nir_deref_instr *instr)
125{
126   while (instr->deref_type != nir_deref_type_var) {
127      /* Consider casts to be indirects */
128      if (instr->deref_type == nir_deref_type_cast)
129         return true;
130
131      if ((instr->deref_type == nir_deref_type_array ||
132           instr->deref_type == nir_deref_type_ptr_as_array) &&
133          !nir_src_is_const(instr->arr.index))
134         return true;
135
136      instr = nir_deref_instr_parent(instr);
137   }
138
139   return false;
140}
141
142bool
143nir_deref_instr_is_known_out_of_bounds(nir_deref_instr *instr)
144{
145   for (; instr; instr = nir_deref_instr_parent(instr)) {
146      if (instr->deref_type == nir_deref_type_array &&
147          nir_src_is_const(instr->arr.index) &&
148           nir_src_as_uint(instr->arr.index) >=
149           glsl_get_length(nir_deref_instr_parent(instr)->type))
150         return true;
151   }
152
153   return false;
154}
155
156bool
157nir_deref_instr_has_complex_use(nir_deref_instr *deref)
158{
159   nir_foreach_use(use_src, &deref->dest.ssa) {
160      nir_instr *use_instr = use_src->parent_instr;
161
162      switch (use_instr->type) {
163      case nir_instr_type_deref: {
164         nir_deref_instr *use_deref = nir_instr_as_deref(use_instr);
165
166         /* A var deref has no sources */
167         assert(use_deref->deref_type != nir_deref_type_var);
168
169         /* If a deref shows up in an array index or something like that, it's
170          * a complex use.
171          */
172         if (use_src != &use_deref->parent)
173            return true;
174
175         /* Anything that isn't a basic struct or array deref is considered to
176          * be a "complex" use.  In particular, we don't allow ptr_as_array
177          * because we assume that opt_deref will turn any non-complex
178          * ptr_as_array derefs into regular array derefs eventually so passes
179          * which only want to handle simple derefs will pick them up in a
180          * later pass.
181          */
182         if (use_deref->deref_type != nir_deref_type_struct &&
183             use_deref->deref_type != nir_deref_type_array_wildcard &&
184             use_deref->deref_type != nir_deref_type_array)
185            return true;
186
187         if (nir_deref_instr_has_complex_use(use_deref))
188            return true;
189
190         continue;
191      }
192
193      case nir_instr_type_intrinsic: {
194         nir_intrinsic_instr *use_intrin = nir_instr_as_intrinsic(use_instr);
195         switch (use_intrin->intrinsic) {
196         case nir_intrinsic_load_deref:
197            assert(use_src == &use_intrin->src[0]);
198            continue;
199
200         case nir_intrinsic_copy_deref:
201            assert(use_src == &use_intrin->src[0] ||
202                   use_src == &use_intrin->src[1]);
203            continue;
204
205         case nir_intrinsic_store_deref:
206            /* A use in src[1] of a store means we're taking that pointer and
207             * writing it to a variable.  Because we have no idea who will
208             * read that variable and what they will do with the pointer, it's
209             * considered a "complex" use.  A use in src[0], on the other
210             * hand, is a simple use because we're just going to dereference
211             * it and write a value there.
212             */
213            if (use_src == &use_intrin->src[0])
214               continue;
215            return true;
216
217         default:
218            return true;
219         }
220         unreachable("Switch default failed");
221      }
222
223      default:
224         return true;
225      }
226   }
227
228   nir_foreach_if_use(use, &deref->dest.ssa)
229      return true;
230
231   return false;
232}
233
234static unsigned
235type_scalar_size_bytes(const struct glsl_type *type)
236{
237   assert(glsl_type_is_vector_or_scalar(type) ||
238          glsl_type_is_matrix(type));
239   return glsl_type_is_boolean(type) ? 4 : glsl_get_bit_size(type) / 8;
240}
241
242unsigned
243nir_deref_instr_array_stride(nir_deref_instr *deref)
244{
245   switch (deref->deref_type) {
246   case nir_deref_type_array:
247   case nir_deref_type_array_wildcard: {
248      const struct glsl_type *arr_type = nir_deref_instr_parent(deref)->type;
249      unsigned stride = glsl_get_explicit_stride(arr_type);
250
251      if ((glsl_type_is_matrix(arr_type) &&
252           glsl_matrix_type_is_row_major(arr_type)) ||
253          (glsl_type_is_vector(arr_type) && stride == 0))
254         stride = type_scalar_size_bytes(arr_type);
255
256      return stride;
257   }
258   case nir_deref_type_ptr_as_array:
259      return nir_deref_instr_array_stride(nir_deref_instr_parent(deref));
260   case nir_deref_type_cast:
261      return deref->cast.ptr_stride;
262   default:
263      return 0;
264   }
265}
266
267static unsigned
268type_get_array_stride(const struct glsl_type *elem_type,
269                      glsl_type_size_align_func size_align)
270{
271   unsigned elem_size, elem_align;
272   size_align(elem_type, &elem_size, &elem_align);
273   return ALIGN_POT(elem_size, elem_align);
274}
275
276static unsigned
277struct_type_get_field_offset(const struct glsl_type *struct_type,
278                             glsl_type_size_align_func size_align,
279                             unsigned field_idx)
280{
281   assert(glsl_type_is_struct_or_ifc(struct_type));
282   unsigned offset = 0;
283   for (unsigned i = 0; i <= field_idx; i++) {
284      unsigned elem_size, elem_align;
285      size_align(glsl_get_struct_field(struct_type, i), &elem_size, &elem_align);
286      offset = ALIGN_POT(offset, elem_align);
287      if (i < field_idx)
288         offset += elem_size;
289   }
290   return offset;
291}
292
293unsigned
294nir_deref_instr_get_const_offset(nir_deref_instr *deref,
295                                 glsl_type_size_align_func size_align)
296{
297   nir_deref_path path;
298   nir_deref_path_init(&path, deref, NULL);
299
300   unsigned offset = 0;
301   for (nir_deref_instr **p = &path.path[1]; *p; p++) {
302      switch ((*p)->deref_type) {
303      case nir_deref_type_array:
304         offset += nir_src_as_uint((*p)->arr.index) *
305                   type_get_array_stride((*p)->type, size_align);
306	 break;
307      case nir_deref_type_struct: {
308         /* p starts at path[1], so this is safe */
309         nir_deref_instr *parent = *(p - 1);
310         offset += struct_type_get_field_offset(parent->type, size_align,
311                                                (*p)->strct.index);
312	 break;
313      }
314      case nir_deref_type_cast:
315         /* A cast doesn't contribute to the offset */
316         break;
317      default:
318         unreachable("Unsupported deref type");
319      }
320   }
321
322   nir_deref_path_finish(&path);
323
324   return offset;
325}
326
327nir_ssa_def *
328nir_build_deref_offset(nir_builder *b, nir_deref_instr *deref,
329                       glsl_type_size_align_func size_align)
330{
331   nir_deref_path path;
332   nir_deref_path_init(&path, deref, NULL);
333
334   nir_ssa_def *offset = nir_imm_intN_t(b, 0, deref->dest.ssa.bit_size);
335   for (nir_deref_instr **p = &path.path[1]; *p; p++) {
336      switch ((*p)->deref_type) {
337      case nir_deref_type_array:
338      case nir_deref_type_ptr_as_array: {
339         nir_ssa_def *index = nir_ssa_for_src(b, (*p)->arr.index, 1);
340         int stride = type_get_array_stride((*p)->type, size_align);
341         offset = nir_iadd(b, offset, nir_amul_imm(b, index, stride));
342         break;
343      }
344      case nir_deref_type_struct: {
345         /* p starts at path[1], so this is safe */
346         nir_deref_instr *parent = *(p - 1);
347         unsigned field_offset =
348            struct_type_get_field_offset(parent->type, size_align,
349                                         (*p)->strct.index);
350         offset = nir_iadd_imm(b, offset, field_offset);
351         break;
352      }
353      case nir_deref_type_cast:
354         /* A cast doesn't contribute to the offset */
355         break;
356      default:
357         unreachable("Unsupported deref type");
358      }
359   }
360
361   nir_deref_path_finish(&path);
362
363   return offset;
364}
365
366bool
367nir_remove_dead_derefs_impl(nir_function_impl *impl)
368{
369   bool progress = false;
370
371   nir_foreach_block(block, impl) {
372      nir_foreach_instr_safe(instr, block) {
373         if (instr->type == nir_instr_type_deref &&
374             nir_deref_instr_remove_if_unused(nir_instr_as_deref(instr)))
375            progress = true;
376      }
377   }
378
379   if (progress)
380      nir_metadata_preserve(impl, nir_metadata_block_index |
381                                  nir_metadata_dominance);
382
383   return progress;
384}
385
386bool
387nir_remove_dead_derefs(nir_shader *shader)
388{
389   bool progress = false;
390   nir_foreach_function(function, shader) {
391      if (function->impl && nir_remove_dead_derefs_impl(function->impl))
392         progress = true;
393   }
394
395   return progress;
396}
397
398void
399nir_fixup_deref_modes(nir_shader *shader)
400{
401   nir_foreach_function(function, shader) {
402      if (!function->impl)
403         continue;
404
405      nir_foreach_block(block, function->impl) {
406         nir_foreach_instr(instr, block) {
407            if (instr->type != nir_instr_type_deref)
408               continue;
409
410            nir_deref_instr *deref = nir_instr_as_deref(instr);
411            if (deref->deref_type == nir_deref_type_cast)
412               continue;
413
414            nir_variable_mode parent_modes;
415            if (deref->deref_type == nir_deref_type_var) {
416               parent_modes = deref->var->data.mode;
417            } else {
418               assert(deref->parent.is_ssa);
419               nir_deref_instr *parent =
420                  nir_instr_as_deref(deref->parent.ssa->parent_instr);
421               parent_modes = parent->modes;
422            }
423
424            deref->modes = parent_modes;
425         }
426      }
427   }
428}
429
430static bool
431modes_may_alias(nir_variable_mode a, nir_variable_mode b)
432{
433   /* Generic pointers can alias with SSBOs */
434   if ((a & (nir_var_mem_ssbo | nir_var_mem_global)) &&
435       (b & (nir_var_mem_ssbo | nir_var_mem_global)))
436      return true;
437
438   /* Pointers can only alias if they share a mode. */
439   return a & b;
440}
441
442static bool
443deref_path_contains_coherent_decoration(nir_deref_path *path)
444{
445   assert(path->path[0]->deref_type == nir_deref_type_var);
446
447   if (path->path[0]->var->data.access & ACCESS_COHERENT)
448      return true;
449
450   for (nir_deref_instr **p = &path->path[1]; *p; p++) {
451      if ((*p)->deref_type != nir_deref_type_struct)
452         continue;
453
454      const struct glsl_type *struct_type = (*(p - 1))->type;
455      const struct glsl_struct_field *field =
456         glsl_get_struct_field_data(struct_type, (*p)->strct.index);
457      if (field->memory_coherent)
458         return true;
459   }
460
461   return false;
462}
463
464nir_deref_compare_result
465nir_compare_deref_paths(nir_deref_path *a_path,
466                        nir_deref_path *b_path)
467{
468   if (!modes_may_alias(b_path->path[0]->modes, a_path->path[0]->modes))
469      return nir_derefs_do_not_alias;
470
471   if (a_path->path[0]->deref_type != b_path->path[0]->deref_type)
472      return nir_derefs_may_alias_bit;
473
474   if (a_path->path[0]->deref_type == nir_deref_type_var) {
475      if (a_path->path[0]->var != b_path->path[0]->var) {
476         /* Shader and function temporaries aren't backed by memory so two
477          * distinct variables never alias.
478          */
479         static const nir_variable_mode temp_var_modes =
480            nir_var_shader_temp | nir_var_function_temp;
481         if (!(a_path->path[0]->modes & ~temp_var_modes) ||
482             !(b_path->path[0]->modes & ~temp_var_modes))
483            return nir_derefs_do_not_alias;
484
485         /* If they are both declared coherent or have coherent somewhere in
486          * their path (due to a member of an interface being declared
487          * coherent), we have to assume we that we could have any kind of
488          * aliasing.  Otherwise, they could still alias but the client didn't
489          * tell us and that's their fault.
490          */
491         if (deref_path_contains_coherent_decoration(a_path) &&
492             deref_path_contains_coherent_decoration(b_path))
493            return nir_derefs_may_alias_bit;
494
495         /* Per SPV_KHR_workgroup_memory_explicit_layout and GL_EXT_shared_memory_block,
496          * shared blocks alias each other.
497          */
498         if (a_path->path[0]->modes & nir_var_mem_shared &&
499             b_path->path[0]->modes & nir_var_mem_shared &&
500             (glsl_type_is_interface(a_path->path[0]->var->type) ||
501              glsl_type_is_interface(b_path->path[0]->var->type))) {
502            assert(glsl_type_is_interface(a_path->path[0]->var->type) &&
503                   glsl_type_is_interface(b_path->path[0]->var->type));
504            return nir_derefs_may_alias_bit;
505         }
506
507         /* If we can chase the deref all the way back to the variable and
508          * they're not the same variable and at least one is not declared
509          * coherent, we know they can't possibly alias.
510          */
511         return nir_derefs_do_not_alias;
512      }
513   } else {
514      assert(a_path->path[0]->deref_type == nir_deref_type_cast);
515      /* If they're not exactly the same cast, it's hard to compare them so we
516       * just assume they alias.  Comparing casts is tricky as there are lots
517       * of things such as mode, type, etc. to make sure work out; for now, we
518       * just assume nit_opt_deref will combine them and compare the deref
519       * instructions.
520       *
521       * TODO: At some point in the future, we could be clever and understand
522       * that a float[] and int[] have the same layout and aliasing structure
523       * but double[] and vec3[] do not and we could potentially be a bit
524       * smarter here.
525       */
526      if (a_path->path[0] != b_path->path[0])
527         return nir_derefs_may_alias_bit;
528   }
529
530   /* Start off assuming they fully compare.  We ignore equality for now.  In
531    * the end, we'll determine that by containment.
532    */
533   nir_deref_compare_result result = nir_derefs_may_alias_bit |
534                                     nir_derefs_a_contains_b_bit |
535                                     nir_derefs_b_contains_a_bit;
536
537   nir_deref_instr **a_p = &a_path->path[1];
538   nir_deref_instr **b_p = &b_path->path[1];
539   while (*a_p != NULL && *a_p == *b_p) {
540      a_p++;
541      b_p++;
542   }
543
544   /* We're at either the tail or the divergence point between the two deref
545    * paths.  Look to see if either contains cast or a ptr_as_array deref.  If
546    * it does we don't know how to safely make any inferences.  Hopefully,
547    * nir_opt_deref will clean most of these up and we can start inferring
548    * things again.
549    *
550    * In theory, we could do a bit better.  For instance, we could detect the
551    * case where we have exactly one ptr_as_array deref in the chain after the
552    * divergence point and it's matched in both chains and the two chains have
553    * different constant indices.
554    */
555   for (nir_deref_instr **t_p = a_p; *t_p; t_p++) {
556      if ((*t_p)->deref_type == nir_deref_type_cast ||
557          (*t_p)->deref_type == nir_deref_type_ptr_as_array)
558         return nir_derefs_may_alias_bit;
559   }
560   for (nir_deref_instr **t_p = b_p; *t_p; t_p++) {
561      if ((*t_p)->deref_type == nir_deref_type_cast ||
562          (*t_p)->deref_type == nir_deref_type_ptr_as_array)
563         return nir_derefs_may_alias_bit;
564   }
565
566   while (*a_p != NULL && *b_p != NULL) {
567      nir_deref_instr *a_tail = *(a_p++);
568      nir_deref_instr *b_tail = *(b_p++);
569
570      switch (a_tail->deref_type) {
571      case nir_deref_type_array:
572      case nir_deref_type_array_wildcard: {
573         assert(b_tail->deref_type == nir_deref_type_array ||
574                b_tail->deref_type == nir_deref_type_array_wildcard);
575
576         if (a_tail->deref_type == nir_deref_type_array_wildcard) {
577            if (b_tail->deref_type != nir_deref_type_array_wildcard)
578               result &= ~nir_derefs_b_contains_a_bit;
579         } else if (b_tail->deref_type == nir_deref_type_array_wildcard) {
580            if (a_tail->deref_type != nir_deref_type_array_wildcard)
581               result &= ~nir_derefs_a_contains_b_bit;
582         } else {
583            assert(a_tail->deref_type == nir_deref_type_array &&
584                   b_tail->deref_type == nir_deref_type_array);
585            assert(a_tail->arr.index.is_ssa && b_tail->arr.index.is_ssa);
586
587            if (nir_src_is_const(a_tail->arr.index) &&
588                nir_src_is_const(b_tail->arr.index)) {
589               /* If they're both direct and have different offsets, they
590                * don't even alias much less anything else.
591                */
592               if (nir_src_as_uint(a_tail->arr.index) !=
593                   nir_src_as_uint(b_tail->arr.index))
594                  return nir_derefs_do_not_alias;
595            } else if (a_tail->arr.index.ssa == b_tail->arr.index.ssa) {
596               /* They're the same indirect, continue on */
597            } else {
598               /* They're not the same index so we can't prove anything about
599                * containment.
600                */
601               result &= ~(nir_derefs_a_contains_b_bit | nir_derefs_b_contains_a_bit);
602            }
603         }
604         break;
605      }
606
607      case nir_deref_type_struct: {
608         /* If they're different struct members, they don't even alias */
609         if (a_tail->strct.index != b_tail->strct.index)
610            return nir_derefs_do_not_alias;
611         break;
612      }
613
614      default:
615         unreachable("Invalid deref type");
616      }
617   }
618
619   /* If a is longer than b, then it can't contain b */
620   if (*a_p != NULL)
621      result &= ~nir_derefs_a_contains_b_bit;
622   if (*b_p != NULL)
623      result &= ~nir_derefs_b_contains_a_bit;
624
625   /* If a contains b and b contains a they must be equal. */
626   if ((result & nir_derefs_a_contains_b_bit) && (result & nir_derefs_b_contains_a_bit))
627      result |= nir_derefs_equal_bit;
628
629   return result;
630}
631
632nir_deref_compare_result
633nir_compare_derefs(nir_deref_instr *a, nir_deref_instr *b)
634{
635   if (a == b) {
636      return nir_derefs_equal_bit | nir_derefs_may_alias_bit |
637             nir_derefs_a_contains_b_bit | nir_derefs_b_contains_a_bit;
638   }
639
640   nir_deref_path a_path, b_path;
641   nir_deref_path_init(&a_path, a, NULL);
642   nir_deref_path_init(&b_path, b, NULL);
643   assert(a_path.path[0]->deref_type == nir_deref_type_var ||
644          a_path.path[0]->deref_type == nir_deref_type_cast);
645   assert(b_path.path[0]->deref_type == nir_deref_type_var ||
646          b_path.path[0]->deref_type == nir_deref_type_cast);
647
648   nir_deref_compare_result result = nir_compare_deref_paths(&a_path, &b_path);
649
650   nir_deref_path_finish(&a_path);
651   nir_deref_path_finish(&b_path);
652
653   return result;
654}
655
656nir_deref_path *nir_get_deref_path(void *mem_ctx, nir_deref_and_path *deref)
657{
658   if (!deref->_path) {
659      deref->_path = ralloc(mem_ctx, nir_deref_path);
660      nir_deref_path_init(deref->_path, deref->instr, mem_ctx);
661   }
662   return deref->_path;
663}
664
665nir_deref_compare_result nir_compare_derefs_and_paths(void *mem_ctx,
666                                                      nir_deref_and_path *a,
667                                                      nir_deref_and_path *b)
668{
669   if (a->instr == b->instr) /* nir_compare_derefs has a fast path if a == b */
670      return nir_compare_derefs(a->instr, b->instr);
671
672   return nir_compare_deref_paths(nir_get_deref_path(mem_ctx, a),
673                                  nir_get_deref_path(mem_ctx, b));
674}
675
676struct rematerialize_deref_state {
677   bool progress;
678   nir_builder builder;
679   nir_block *block;
680   struct hash_table *cache;
681};
682
683static nir_deref_instr *
684rematerialize_deref_in_block(nir_deref_instr *deref,
685                             struct rematerialize_deref_state *state)
686{
687   if (deref->instr.block == state->block)
688      return deref;
689
690   if (!state->cache) {
691      state->cache = _mesa_pointer_hash_table_create(NULL);
692   }
693
694   struct hash_entry *cached = _mesa_hash_table_search(state->cache, deref);
695   if (cached)
696      return cached->data;
697
698   nir_builder *b = &state->builder;
699   nir_deref_instr *new_deref =
700      nir_deref_instr_create(b->shader, deref->deref_type);
701   new_deref->modes = deref->modes;
702   new_deref->type = deref->type;
703
704   if (deref->deref_type == nir_deref_type_var) {
705      new_deref->var = deref->var;
706   } else {
707      nir_deref_instr *parent = nir_src_as_deref(deref->parent);
708      if (parent) {
709         parent = rematerialize_deref_in_block(parent, state);
710         new_deref->parent = nir_src_for_ssa(&parent->dest.ssa);
711      } else {
712         nir_src_copy(&new_deref->parent, &deref->parent);
713      }
714   }
715
716   switch (deref->deref_type) {
717   case nir_deref_type_var:
718   case nir_deref_type_array_wildcard:
719      /* Nothing more to do */
720      break;
721
722   case nir_deref_type_cast:
723      new_deref->cast.ptr_stride = deref->cast.ptr_stride;
724      break;
725
726   case nir_deref_type_array:
727   case nir_deref_type_ptr_as_array:
728      assert(!nir_src_as_deref(deref->arr.index));
729      nir_src_copy(&new_deref->arr.index, &deref->arr.index);
730      break;
731
732   case nir_deref_type_struct:
733      new_deref->strct.index = deref->strct.index;
734      break;
735
736   default:
737      unreachable("Invalid deref instruction type");
738   }
739
740   nir_ssa_dest_init(&new_deref->instr, &new_deref->dest,
741                     deref->dest.ssa.num_components,
742                     deref->dest.ssa.bit_size,
743                     NULL);
744   nir_builder_instr_insert(b, &new_deref->instr);
745
746   return new_deref;
747}
748
749static bool
750rematerialize_deref_src(nir_src *src, void *_state)
751{
752   struct rematerialize_deref_state *state = _state;
753
754   nir_deref_instr *deref = nir_src_as_deref(*src);
755   if (!deref)
756      return true;
757
758   nir_deref_instr *block_deref = rematerialize_deref_in_block(deref, state);
759   if (block_deref != deref) {
760      nir_instr_rewrite_src(src->parent_instr, src,
761                            nir_src_for_ssa(&block_deref->dest.ssa));
762      nir_deref_instr_remove_if_unused(deref);
763      state->progress = true;
764   }
765
766   return true;
767}
768
769/** Re-materialize derefs in every block
770 *
771 * This pass re-materializes deref instructions in every block in which it is
772 * used.  After this pass has been run, every use of a deref will be of a
773 * deref in the same block as the use.  Also, all unused derefs will be
774 * deleted as a side-effect.
775 *
776 * Derefs used as sources of phi instructions are not rematerialized.
777 */
778bool
779nir_rematerialize_derefs_in_use_blocks_impl(nir_function_impl *impl)
780{
781   struct rematerialize_deref_state state = { 0 };
782   nir_builder_init(&state.builder, impl);
783
784   nir_foreach_block_unstructured(block, impl) {
785      state.block = block;
786
787      /* Start each block with a fresh cache */
788      if (state.cache)
789         _mesa_hash_table_clear(state.cache, NULL);
790
791      nir_foreach_instr_safe(instr, block) {
792         if (instr->type == nir_instr_type_deref &&
793             nir_deref_instr_remove_if_unused(nir_instr_as_deref(instr)))
794            continue;
795
796         /* If a deref is used in a phi, we can't rematerialize it, as the new
797          * derefs would appear before the phi, which is not valid.
798          */
799         if (instr->type == nir_instr_type_phi)
800            continue;
801
802         state.builder.cursor = nir_before_instr(instr);
803         nir_foreach_src(instr, rematerialize_deref_src, &state);
804      }
805
806#ifndef NDEBUG
807      nir_if *following_if = nir_block_get_following_if(block);
808      if (following_if)
809         assert(!nir_src_as_deref(following_if->condition));
810#endif
811   }
812
813   _mesa_hash_table_destroy(state.cache, NULL);
814
815   return state.progress;
816}
817
818static void
819nir_deref_instr_fixup_child_types(nir_deref_instr *parent)
820{
821   nir_foreach_use(use, &parent->dest.ssa) {
822      if (use->parent_instr->type != nir_instr_type_deref)
823         continue;
824
825      nir_deref_instr *child = nir_instr_as_deref(use->parent_instr);
826      switch (child->deref_type) {
827      case nir_deref_type_var:
828         unreachable("nir_deref_type_var cannot be a child");
829
830      case nir_deref_type_array:
831      case nir_deref_type_array_wildcard:
832         child->type = glsl_get_array_element(parent->type);
833         break;
834
835      case nir_deref_type_ptr_as_array:
836         child->type = parent->type;
837         break;
838
839      case nir_deref_type_struct:
840         child->type = glsl_get_struct_field(parent->type,
841                                             child->strct.index);
842         break;
843
844      case nir_deref_type_cast:
845         /* We stop the recursion here */
846         continue;
847      }
848
849      /* Recurse into children */
850      nir_deref_instr_fixup_child_types(child);
851   }
852}
853
854static bool
855is_trivial_array_deref_cast(nir_deref_instr *cast)
856{
857   assert(is_trivial_deref_cast(cast));
858
859   nir_deref_instr *parent = nir_src_as_deref(cast->parent);
860
861   if (parent->deref_type == nir_deref_type_array) {
862      return cast->cast.ptr_stride ==
863             glsl_get_explicit_stride(nir_deref_instr_parent(parent)->type);
864   } else if (parent->deref_type == nir_deref_type_ptr_as_array) {
865      return cast->cast.ptr_stride ==
866             nir_deref_instr_array_stride(parent);
867   } else {
868      return false;
869   }
870}
871
872static bool
873is_deref_ptr_as_array(nir_instr *instr)
874{
875   return instr->type == nir_instr_type_deref &&
876          nir_instr_as_deref(instr)->deref_type == nir_deref_type_ptr_as_array;
877}
878
879static bool
880opt_remove_restricting_cast_alignments(nir_deref_instr *cast)
881{
882   assert(cast->deref_type == nir_deref_type_cast);
883   if (cast->cast.align_mul == 0)
884      return false;
885
886   nir_deref_instr *parent = nir_src_as_deref(cast->parent);
887   if (parent == NULL)
888      return false;
889
890   /* Don't use any default alignment for this check.  We don't want to fall
891    * back to type alignment too early in case we find out later that we're
892    * somehow a child of a packed struct.
893    */
894   uint32_t parent_mul, parent_offset;
895   if (!nir_get_explicit_deref_align(parent, false /* default_to_type_align */,
896                                     &parent_mul, &parent_offset))
897      return false;
898
899   /* If this cast increases the alignment, we want to keep it.
900    *
901    * There is a possibility that the larger alignment provided by this cast
902    * somehow disagrees with the smaller alignment further up the deref chain.
903    * In that case, we choose to favor the alignment closer to the actual
904    * memory operation which, in this case, is the cast and not its parent so
905    * keeping the cast alignment is the right thing to do.
906    */
907   if (parent_mul < cast->cast.align_mul)
908      return false;
909
910   /* If we've gotten here, we have a parent deref with an align_mul at least
911    * as large as ours so we can potentially throw away the alignment
912    * information on this deref.  There are two cases to consider here:
913    *
914    *  1. We can chase the deref all the way back to the variable.  In this
915    *     case, we have "perfect" knowledge, modulo indirect array derefs.
916    *     Unless we've done something wrong in our indirect/wildcard stride
917    *     calculations, our knowledge from the deref walk is better than the
918    *     client's.
919    *
920    *  2. We can't chase it all the way back to the variable.  In this case,
921    *     because our call to nir_get_explicit_deref_align(parent, ...) above
922    *     above passes default_to_type_align=false, the only way we can even
923    *     get here is if something further up the deref chain has a cast with
924    *     an alignment which can only happen if we get an alignment from the
925    *     client (most likely a decoration in the SPIR-V).  If the client has
926    *     provided us with two conflicting alignments in the deref chain,
927    *     that's their fault and we can do whatever we want.
928    *
929    * In either case, we should be without our rights, at this point, to throw
930    * away the alignment information on this deref.  However, to be "nice" to
931    * weird clients, we do one more check.  It really shouldn't happen but
932    * it's possible that the parent's alignment offset disagrees with the
933    * cast's alignment offset.  In this case, we consider the cast as
934    * providing more information (or at least more valid information) and keep
935    * it even if the align_mul from the parent is larger.
936    */
937   assert(cast->cast.align_mul <= parent_mul);
938   if (parent_offset % cast->cast.align_mul != cast->cast.align_offset)
939      return false;
940
941   /* If we got here, the parent has better alignment information than the
942    * child and we can get rid of the child alignment information.
943    */
944   cast->cast.align_mul = 0;
945   cast->cast.align_offset = 0;
946   return true;
947}
948
949/**
950 * Remove casts that just wrap other casts.
951 */
952static bool
953opt_remove_cast_cast(nir_deref_instr *cast)
954{
955   nir_deref_instr *first_cast = cast;
956
957   while (true) {
958      nir_deref_instr *parent = nir_deref_instr_parent(first_cast);
959      if (parent == NULL || parent->deref_type != nir_deref_type_cast)
960         break;
961      first_cast = parent;
962   }
963   if (cast == first_cast)
964      return false;
965
966   nir_instr_rewrite_src(&cast->instr, &cast->parent,
967                         nir_src_for_ssa(first_cast->parent.ssa));
968   return true;
969}
970
971/* Restrict variable modes in casts.
972 *
973 * If we know from something higher up the deref chain that the deref has a
974 * specific mode, we can cast to more general and back but we can never cast
975 * across modes.  For non-cast derefs, we should only ever do anything here if
976 * the parent eventually comes from a cast that we restricted earlier.
977 */
978static bool
979opt_restrict_deref_modes(nir_deref_instr *deref)
980{
981   if (deref->deref_type == nir_deref_type_var) {
982      assert(deref->modes == deref->var->data.mode);
983      return false;
984   }
985
986   nir_deref_instr *parent = nir_src_as_deref(deref->parent);
987   if (parent == NULL || parent->modes == deref->modes)
988      return false;
989
990   assert(parent->modes & deref->modes);
991   deref->modes &= parent->modes;
992   return true;
993}
994
995static bool
996opt_remove_sampler_cast(nir_deref_instr *cast)
997{
998   assert(cast->deref_type == nir_deref_type_cast);
999   nir_deref_instr *parent = nir_src_as_deref(cast->parent);
1000   if (parent == NULL)
1001      return false;
1002
1003   /* Strip both types down to their non-array type and bail if there are any
1004    * discrepancies in array lengths.
1005    */
1006   const struct glsl_type *parent_type = parent->type;
1007   const struct glsl_type *cast_type = cast->type;
1008   while (glsl_type_is_array(parent_type) && glsl_type_is_array(cast_type)) {
1009      if (glsl_get_length(parent_type) != glsl_get_length(cast_type))
1010         return false;
1011      parent_type = glsl_get_array_element(parent_type);
1012      cast_type = glsl_get_array_element(cast_type);
1013   }
1014
1015   if (glsl_type_is_array(parent_type) || glsl_type_is_array(cast_type))
1016      return false;
1017
1018   if (!glsl_type_is_sampler(parent_type) ||
1019       cast_type != glsl_bare_sampler_type())
1020      return false;
1021
1022   /* We're a cast from a more detailed sampler type to a bare sampler */
1023   nir_ssa_def_rewrite_uses(&cast->dest.ssa,
1024                            &parent->dest.ssa);
1025   nir_instr_remove(&cast->instr);
1026
1027   /* Recursively crawl the deref tree and clean up types */
1028   nir_deref_instr_fixup_child_types(parent);
1029
1030   return true;
1031}
1032
1033/**
1034 * Is this casting a struct to a contained struct.
1035 * struct a { struct b field0 };
1036 * ssa_5 is structa;
1037 * deref_cast (structb *)ssa_5 (function_temp structb);
1038 * converts to
1039 * deref_struct &ssa_5->field0 (function_temp structb);
1040 * This allows subsequent copy propagation to work.
1041 */
1042static bool
1043opt_replace_struct_wrapper_cast(nir_builder *b, nir_deref_instr *cast)
1044{
1045   nir_deref_instr *parent = nir_src_as_deref(cast->parent);
1046   if (!parent)
1047      return false;
1048
1049   if (cast->cast.align_mul > 0)
1050      return false;
1051
1052   if (!glsl_type_is_struct(parent->type))
1053      return false;
1054
1055   /* Empty struct */
1056   if (glsl_get_length(parent->type) < 1)
1057      return false;
1058
1059   if (glsl_get_struct_field_offset(parent->type, 0) != 0)
1060      return false;
1061
1062   if (cast->type != glsl_get_struct_field(parent->type, 0))
1063      return false;
1064
1065   nir_deref_instr *replace = nir_build_deref_struct(b, parent, 0);
1066   nir_ssa_def_rewrite_uses(&cast->dest.ssa, &replace->dest.ssa);
1067   nir_deref_instr_remove_if_unused(cast);
1068   return true;
1069}
1070
1071static bool
1072opt_deref_cast(nir_builder *b, nir_deref_instr *cast)
1073{
1074   bool progress = false;
1075
1076   progress |= opt_remove_restricting_cast_alignments(cast);
1077
1078   if (opt_replace_struct_wrapper_cast(b, cast))
1079      return true;
1080
1081   if (opt_remove_sampler_cast(cast))
1082      return true;
1083
1084   progress |= opt_remove_cast_cast(cast);
1085   if (!is_trivial_deref_cast(cast))
1086      return progress;
1087
1088   /* If this deref still contains useful alignment information, we don't want
1089    * to delete it.
1090    */
1091   if (cast->cast.align_mul > 0)
1092      return progress;
1093
1094   bool trivial_array_cast = is_trivial_array_deref_cast(cast);
1095
1096   assert(cast->dest.is_ssa);
1097   assert(cast->parent.is_ssa);
1098
1099   nir_foreach_use_safe(use_src, &cast->dest.ssa) {
1100      /* If this isn't a trivial array cast, we can't propagate into
1101       * ptr_as_array derefs.
1102       */
1103      if (is_deref_ptr_as_array(use_src->parent_instr) &&
1104          !trivial_array_cast)
1105         continue;
1106
1107      nir_instr_rewrite_src(use_src->parent_instr, use_src, cast->parent);
1108      progress = true;
1109   }
1110
1111   /* If uses would be a bit crazy */
1112   assert(list_is_empty(&cast->dest.ssa.if_uses));
1113
1114   if (nir_deref_instr_remove_if_unused(cast))
1115      progress = true;
1116
1117   return progress;
1118}
1119
1120static bool
1121opt_deref_ptr_as_array(nir_builder *b, nir_deref_instr *deref)
1122{
1123   assert(deref->deref_type == nir_deref_type_ptr_as_array);
1124
1125   nir_deref_instr *parent = nir_deref_instr_parent(deref);
1126
1127   if (nir_src_is_const(deref->arr.index) &&
1128       nir_src_as_int(deref->arr.index) == 0) {
1129      /* If it's a ptr_as_array deref with an index of 0, it does nothing
1130       * and we can just replace its uses with its parent, unless it has
1131       * alignment information.
1132       *
1133       * The source of a ptr_as_array deref always has a deref_type of
1134       * nir_deref_type_array or nir_deref_type_cast.  If it's a cast, it
1135       * may be trivial and we may be able to get rid of that too.  Any
1136       * trivial cast of trivial cast cases should be handled already by
1137       * opt_deref_cast() above.
1138       */
1139      if (parent->deref_type == nir_deref_type_cast &&
1140          parent->cast.align_mul == 0 &&
1141          is_trivial_deref_cast(parent))
1142         parent = nir_deref_instr_parent(parent);
1143      nir_ssa_def_rewrite_uses(&deref->dest.ssa,
1144                               &parent->dest.ssa);
1145      nir_instr_remove(&deref->instr);
1146      return true;
1147   }
1148
1149   if (parent->deref_type != nir_deref_type_array &&
1150       parent->deref_type != nir_deref_type_ptr_as_array)
1151      return false;
1152
1153   assert(parent->parent.is_ssa);
1154   assert(parent->arr.index.is_ssa);
1155   assert(deref->arr.index.is_ssa);
1156
1157   nir_ssa_def *new_idx = nir_iadd(b, parent->arr.index.ssa,
1158                                      deref->arr.index.ssa);
1159
1160   deref->deref_type = parent->deref_type;
1161   nir_instr_rewrite_src(&deref->instr, &deref->parent, parent->parent);
1162   nir_instr_rewrite_src(&deref->instr, &deref->arr.index,
1163                         nir_src_for_ssa(new_idx));
1164   return true;
1165}
1166
1167static bool
1168is_vector_bitcast_deref(nir_deref_instr *cast,
1169                        nir_component_mask_t mask,
1170                        bool is_write)
1171{
1172   if (cast->deref_type != nir_deref_type_cast)
1173      return false;
1174
1175   /* Don't throw away useful alignment information */
1176   if (cast->cast.align_mul > 0)
1177      return false;
1178
1179   /* It has to be a cast of another deref */
1180   nir_deref_instr *parent = nir_src_as_deref(cast->parent);
1181   if (parent == NULL)
1182      return false;
1183
1184   /* The parent has to be a vector or scalar */
1185   if (!glsl_type_is_vector_or_scalar(parent->type))
1186      return false;
1187
1188   /* Don't bother with 1-bit types */
1189   unsigned cast_bit_size = glsl_get_bit_size(cast->type);
1190   unsigned parent_bit_size = glsl_get_bit_size(parent->type);
1191   if (cast_bit_size == 1 || parent_bit_size == 1)
1192      return false;
1193
1194   /* A strided vector type means it's not tightly packed */
1195   if (glsl_get_explicit_stride(cast->type) ||
1196       glsl_get_explicit_stride(parent->type))
1197      return false;
1198
1199   assert(cast_bit_size > 0 && cast_bit_size % 8 == 0);
1200   assert(parent_bit_size > 0 && parent_bit_size % 8 == 0);
1201   unsigned bytes_used = util_last_bit(mask) * (cast_bit_size / 8);
1202   unsigned parent_bytes = glsl_get_vector_elements(parent->type) *
1203                           (parent_bit_size / 8);
1204   if (bytes_used > parent_bytes)
1205      return false;
1206
1207   if (is_write && !nir_component_mask_can_reinterpret(mask, cast_bit_size,
1208                                                       parent_bit_size))
1209      return false;
1210
1211   return true;
1212}
1213
1214static nir_ssa_def *
1215resize_vector(nir_builder *b, nir_ssa_def *data, unsigned num_components)
1216{
1217   if (num_components == data->num_components)
1218      return data;
1219
1220   unsigned swiz[NIR_MAX_VEC_COMPONENTS] = { 0, };
1221   for (unsigned i = 0; i < MIN2(num_components, data->num_components); i++)
1222      swiz[i] = i;
1223
1224   return nir_swizzle(b, data, swiz, num_components);
1225}
1226
1227static bool
1228opt_load_vec_deref(nir_builder *b, nir_intrinsic_instr *load)
1229{
1230   nir_deref_instr *deref = nir_src_as_deref(load->src[0]);
1231   nir_component_mask_t read_mask =
1232      nir_ssa_def_components_read(&load->dest.ssa);
1233
1234   /* LLVM loves take advantage of the fact that vec3s in OpenCL are
1235    * vec4-aligned and so it can just read/write them as vec4s.  This
1236    * results in a LOT of vec4->vec3 casts on loads and stores.
1237    */
1238   if (is_vector_bitcast_deref(deref, read_mask, false)) {
1239      const unsigned old_num_comps = load->dest.ssa.num_components;
1240      const unsigned old_bit_size = load->dest.ssa.bit_size;
1241
1242      nir_deref_instr *parent = nir_src_as_deref(deref->parent);
1243      const unsigned new_num_comps = glsl_get_vector_elements(parent->type);
1244      const unsigned new_bit_size = glsl_get_bit_size(parent->type);
1245
1246      /* Stomp it to reference the parent */
1247      nir_instr_rewrite_src(&load->instr, &load->src[0],
1248                            nir_src_for_ssa(&parent->dest.ssa));
1249      assert(load->dest.is_ssa);
1250      load->dest.ssa.bit_size = new_bit_size;
1251      load->dest.ssa.num_components = new_num_comps;
1252      load->num_components = new_num_comps;
1253
1254      b->cursor = nir_after_instr(&load->instr);
1255      nir_ssa_def *data = &load->dest.ssa;
1256      if (old_bit_size != new_bit_size)
1257         data = nir_bitcast_vector(b, &load->dest.ssa, old_bit_size);
1258      data = resize_vector(b, data, old_num_comps);
1259
1260      nir_ssa_def_rewrite_uses_after(&load->dest.ssa, data,
1261                                     data->parent_instr);
1262      return true;
1263   }
1264
1265   return false;
1266}
1267
1268static bool
1269opt_store_vec_deref(nir_builder *b, nir_intrinsic_instr *store)
1270{
1271   nir_deref_instr *deref = nir_src_as_deref(store->src[0]);
1272   nir_component_mask_t write_mask = nir_intrinsic_write_mask(store);
1273
1274   /* LLVM loves take advantage of the fact that vec3s in OpenCL are
1275    * vec4-aligned and so it can just read/write them as vec4s.  This
1276    * results in a LOT of vec4->vec3 casts on loads and stores.
1277    */
1278   if (is_vector_bitcast_deref(deref, write_mask, true)) {
1279      assert(store->src[1].is_ssa);
1280      nir_ssa_def *data = store->src[1].ssa;
1281
1282      const unsigned old_bit_size = data->bit_size;
1283
1284      nir_deref_instr *parent = nir_src_as_deref(deref->parent);
1285      const unsigned new_num_comps = glsl_get_vector_elements(parent->type);
1286      const unsigned new_bit_size = glsl_get_bit_size(parent->type);
1287
1288      nir_instr_rewrite_src(&store->instr, &store->src[0],
1289                            nir_src_for_ssa(&parent->dest.ssa));
1290
1291      /* Restrict things down as needed so the bitcast doesn't fail */
1292      data = nir_channels(b, data, (1 << util_last_bit(write_mask)) - 1);
1293      if (old_bit_size != new_bit_size)
1294         data = nir_bitcast_vector(b, data, new_bit_size);
1295      data = resize_vector(b, data, new_num_comps);
1296      nir_instr_rewrite_src(&store->instr, &store->src[1],
1297                            nir_src_for_ssa(data));
1298      store->num_components = new_num_comps;
1299
1300      /* Adjust the write mask */
1301      write_mask = nir_component_mask_reinterpret(write_mask, old_bit_size,
1302                                                  new_bit_size);
1303      nir_intrinsic_set_write_mask(store, write_mask);
1304      return true;
1305   }
1306
1307   return false;
1308}
1309
1310static bool
1311opt_known_deref_mode_is(nir_builder *b, nir_intrinsic_instr *intrin)
1312{
1313   nir_variable_mode modes = nir_intrinsic_memory_modes(intrin);
1314   nir_deref_instr *deref = nir_src_as_deref(intrin->src[0]);
1315   if (deref == NULL)
1316      return false;
1317
1318   nir_ssa_def *deref_is = NULL;
1319
1320   if (nir_deref_mode_must_be(deref, modes))
1321      deref_is = nir_imm_true(b);
1322
1323   if (!nir_deref_mode_may_be(deref, modes))
1324      deref_is = nir_imm_false(b);
1325
1326   if (deref_is == NULL)
1327      return false;
1328
1329   nir_ssa_def_rewrite_uses(&intrin->dest.ssa, deref_is);
1330   nir_instr_remove(&intrin->instr);
1331   return true;
1332}
1333
1334bool
1335nir_opt_deref_impl(nir_function_impl *impl)
1336{
1337   bool progress = false;
1338
1339   nir_builder b;
1340   nir_builder_init(&b, impl);
1341
1342   nir_foreach_block(block, impl) {
1343      nir_foreach_instr_safe(instr, block) {
1344         b.cursor = nir_before_instr(instr);
1345
1346         switch (instr->type) {
1347         case nir_instr_type_deref: {
1348            nir_deref_instr *deref = nir_instr_as_deref(instr);
1349
1350            if (opt_restrict_deref_modes(deref))
1351               progress = true;
1352
1353            switch (deref->deref_type) {
1354            case nir_deref_type_ptr_as_array:
1355               if (opt_deref_ptr_as_array(&b, deref))
1356                  progress = true;
1357               break;
1358
1359            case nir_deref_type_cast:
1360               if (opt_deref_cast(&b, deref))
1361                  progress = true;
1362               break;
1363
1364            default:
1365               /* Do nothing */
1366               break;
1367            }
1368            break;
1369         }
1370
1371         case nir_instr_type_intrinsic: {
1372            nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
1373            switch (intrin->intrinsic) {
1374            case nir_intrinsic_load_deref:
1375               if (opt_load_vec_deref(&b, intrin))
1376                  progress = true;
1377               break;
1378
1379            case nir_intrinsic_store_deref:
1380               if (opt_store_vec_deref(&b, intrin))
1381                  progress = true;
1382               break;
1383
1384            case nir_intrinsic_deref_mode_is:
1385               if (opt_known_deref_mode_is(&b, intrin))
1386                  progress = true;
1387               break;
1388
1389            default:
1390               /* Do nothing */
1391               break;
1392            }
1393            break;
1394         }
1395
1396         default:
1397            /* Do nothing */
1398            break;
1399         }
1400      }
1401   }
1402
1403   if (progress) {
1404      nir_metadata_preserve(impl, nir_metadata_block_index |
1405                                  nir_metadata_dominance);
1406   } else {
1407      nir_metadata_preserve(impl, nir_metadata_all);
1408   }
1409
1410   return progress;
1411}
1412
1413bool
1414nir_opt_deref(nir_shader *shader)
1415{
1416   bool progress = false;
1417
1418   nir_foreach_function(func, shader) {
1419      if (func->impl && nir_opt_deref_impl(func->impl))
1420         progress = true;
1421   }
1422
1423   return progress;
1424}
1425