1/*
2 * Copyright © 2016 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
27static bool
28deref_apply_constant_initializer(nir_deref_var *deref, void *state)
29{
30   struct nir_builder *b = state;
31
32   nir_load_const_instr *initializer =
33      nir_deref_get_const_initializer_load(b->shader, deref);
34   nir_builder_instr_insert(b, &initializer->instr);
35
36   nir_store_deref_var(b, deref, &initializer->def, 0xf);
37
38   return true;
39}
40
41static bool
42lower_const_initializer(struct nir_builder *b, struct exec_list *var_list)
43{
44   bool progress = false;
45
46   b->cursor = nir_before_cf_list(&b->impl->body);
47
48   nir_foreach_variable(var, var_list) {
49      if (!var->constant_initializer)
50         continue;
51
52      progress = true;
53
54      nir_deref_var deref;
55      deref.deref.deref_type = nir_deref_type_var,
56      deref.deref.child = NULL;
57      deref.deref.type = var->type,
58      deref.var = var;
59
60      nir_deref_foreach_leaf(&deref, deref_apply_constant_initializer, b);
61
62      var->constant_initializer = NULL;
63   }
64
65   return progress;
66}
67
68bool
69nir_lower_constant_initializers(nir_shader *shader, nir_variable_mode modes)
70{
71   bool progress = false;
72
73   nir_builder builder;
74   if (modes & ~nir_var_local)
75      nir_builder_init(&builder, nir_shader_get_entrypoint(shader));
76
77   if (modes & nir_var_shader_out)
78      progress |= lower_const_initializer(&builder, &shader->outputs);
79
80   if (modes & nir_var_global)
81      progress |= lower_const_initializer(&builder, &shader->globals);
82
83   if (modes & nir_var_system_value)
84      progress |= lower_const_initializer(&builder, &shader->system_values);
85
86   if (progress) {
87      nir_foreach_function(function, shader) {
88         if (function->impl) {
89            nir_metadata_preserve(function->impl, nir_metadata_block_index |
90                                                  nir_metadata_dominance |
91                                                  nir_metadata_live_ssa_defs);
92         }
93      }
94   }
95
96   if (modes & nir_var_local) {
97      nir_foreach_function(function, shader) {
98         if (!function->impl)
99            continue;
100
101         nir_builder_init(&builder, function->impl);
102         if (lower_const_initializer(&builder, &function->impl->locals)) {
103            nir_metadata_preserve(function->impl, nir_metadata_block_index |
104                                                  nir_metadata_dominance |
105                                                  nir_metadata_live_ssa_defs);
106            progress = true;
107         }
108      }
109   }
110
111   return progress;
112}
113