src/compiler/nir/nir_lower_system_values.c

   1 /*
   2  * Copyright © 2014 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  * Authors:
  24  *    Connor Abbott (cwabbott0@gmail.com)
  25  *
  26  */
  27
  28 #include "nir.h"
  29 #include "nir_builder.h"
  30
  31 struct lower_system_values_state {
  32    nir_builder builder;
  33    bool progress;
  34 };
  35
  36 static bool
  37 convert_block(nir_block *block, void *void_state)
  38 {
  39    struct lower_system_values_state *state = void_state;
  40
  41    nir_builder *b = &state->builder;
  42
  43    nir_foreach_instr_safe(block, instr) {
  44       if (instr->type != nir_instr_type_intrinsic)
  45          continue;
  46
  47       nir_intrinsic_instr *load_var = nir_instr_as_intrinsic(instr);
  48
  49       if (load_var->intrinsic != nir_intrinsic_load_var)
  50          continue;
  51
  52       nir_variable *var = load_var->variables[0]->var;
  53       if (var->data.mode != nir_var_system_value)
  54          continue;
  55
  56       b->cursor = nir_after_instr(&load_var->instr);
  57
  58       nir_intrinsic_op sysval_op =
  59          nir_intrinsic_from_system_value(var->data.location);
  60       nir_ssa_def *sysval = nir_load_system_value(b, sysval_op, 0);
  61
  62       nir_ssa_def_rewrite_uses(&load_var->dest.ssa, nir_src_for_ssa(sysval));
  63       nir_instr_remove(&load_var->instr);
  64
  65       state->progress = true;
  66    }
  67
  68    return true;
  69 }
  70
  71 static bool
  72 convert_impl(nir_function_impl *impl)
  73 {
  74    struct lower_system_values_state state;
  75
  76    state.progress = false;
  77    nir_builder_init(&state.builder, impl);
  78
  79    nir_foreach_block(impl, convert_block, &state);
  80    nir_metadata_preserve(impl, nir_metadata_block_index |
  81                                nir_metadata_dominance);
  82    return state.progress;
  83 }
  84
  85 bool
  86 nir_lower_system_values(nir_shader *shader)
  87 {
  88    bool progress = false;
  89
  90    nir_foreach_function(shader, function) {
  91       if (function->impl)
  92          progress = convert_impl(function->impl) || progress;
  93    }
  94
  95    exec_list_make_empty(&shader->system_values);
  96
  97    return progress;
  98 }