src/compiler/nir/nir_lower_constant_initializers.c

   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
  27 static bool
  28 deref_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
  41 static bool
  42 lower_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
  68 bool
  69 nir_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 }