src/compiler/nir/nir_opt_intrinsics.c

   1 /*
   2  * Copyright © 2017 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 /**
  28  * \file nir_opt_intrinsics.c
  29  */
  30
  31 static bool
  32 opt_intrinsics_impl(nir_function_impl *impl,
  33                     const struct nir_shader_compiler_options *options)
  34 {
  35    nir_builder b;
  36    nir_builder_init(&b, impl);
  37    bool progress = false;
  38
  39    nir_foreach_block(block, impl) {
  40       nir_foreach_instr_safe(instr, block) {
  41          if (instr->type != nir_instr_type_intrinsic)
  42             continue;
  43
  44          nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
  45          nir_ssa_def *replacement = NULL;
  46          b.cursor = nir_before_instr(instr);
  47
  48          switch (intrin->intrinsic) {
  49          case nir_intrinsic_vote_any:
  50          case nir_intrinsic_vote_all:
  51             if (nir_src_is_const(intrin->src[0]))
  52                replacement = nir_ssa_for_src(&b, intrin->src[0], 1);
  53             break;
  54          case nir_intrinsic_vote_feq:
  55          case nir_intrinsic_vote_ieq:
  56             if (nir_src_is_const(intrin->src[0]))
  57                replacement = nir_imm_true(&b);
  58             break;
  59          case nir_intrinsic_load_sample_mask_in:
  60             /* Transform:
  61              *   gl_SampleMaskIn == 0 ---> gl_HelperInvocation
  62              *   gl_SampleMaskIn != 0 ---> !gl_HelperInvocation
  63              */
  64             if (!options->optimize_sample_mask_in)
  65                continue;
  66
  67             nir_foreach_use_safe(use_src, &intrin->dest.ssa) {
  68                if (use_src->parent_instr->type == nir_instr_type_alu) {
  69                   nir_alu_instr *alu = nir_instr_as_alu(use_src->parent_instr);
  70
  71                   if (alu->op == nir_op_ieq ||
  72                       alu->op == nir_op_ine) {
  73                      /* Check for 0 in either operand. */
  74                      nir_const_value *const_val =
  75                          nir_src_as_const_value(alu->src[0].src);
  76                      if (!const_val)
  77                         const_val = nir_src_as_const_value(alu->src[1].src);
  78                      if (!const_val || const_val->i32 != 0)
  79                         continue;
  80
  81                      nir_ssa_def *new_expr = nir_load_helper_invocation(&b, 1);
  82
  83                      if (alu->op == nir_op_ine)
  84                         new_expr = nir_inot(&b, new_expr);
  85
  86                      nir_ssa_def_rewrite_uses(&alu->dest.dest.ssa,
  87                                               nir_src_for_ssa(new_expr));
  88                      nir_instr_remove(&alu->instr);
  89                      continue;
  90                   }
  91                }
  92             }
  93             continue;
  94          default:
  95             break;
  96          }
  97
  98          if (!replacement)
  99             continue;
 100
 101          nir_ssa_def_rewrite_uses(&intrin->dest.ssa,
 102                                   nir_src_for_ssa(replacement));
 103          nir_instr_remove(instr);
 104          progress = true;
 105       }
 106    }
 107
 108    return progress;
 109 }
 110
 111 bool
 112 nir_opt_intrinsics(nir_shader *shader)
 113 {
 114    bool progress = false;
 115
 116    nir_foreach_function(function, shader) {
 117       if (!function->impl)
 118          continue;
 119
 120       if (opt_intrinsics_impl(function->impl, shader->options)) {
 121          progress = true;
 122          nir_metadata_preserve(function->impl, nir_metadata_block_index |
 123                                                nir_metadata_dominance);
 124       }
 125    }
 126
 127    return progress;
 128 }