src/glsl/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 "main/mtypes.h"
  30
  31 static bool
  32 convert_instr(nir_intrinsic_instr *instr)
  33 {
  34    if (instr->intrinsic != nir_intrinsic_load_var)
  35       return false;
  36
  37    nir_variable *var = instr->variables[0]->var;
  38    if (var->data.mode != nir_var_system_value)
  39       return false;
  40
  41    void *mem_ctx = ralloc_parent(instr);
  42
  43    nir_intrinsic_op op = nir_intrinsic_from_system_value(var->data.location);
  44    nir_intrinsic_instr *new_instr = nir_intrinsic_instr_create(mem_ctx, op);
  45
  46    if (instr->dest.is_ssa) {
  47       nir_ssa_dest_init(&new_instr->instr, &new_instr->dest,
  48                         instr->dest.ssa.num_components, NULL);
  49       nir_ssa_def_rewrite_uses(&instr->dest.ssa,
  50                                nir_src_for_ssa(&new_instr->dest.ssa));
  51    } else {
  52       nir_dest_copy(&new_instr->dest, &instr->dest, mem_ctx);
  53    }
  54
  55    nir_instr_insert_before(&instr->instr, &new_instr->instr);
  56    nir_instr_remove(&instr->instr);
  57
  58    return true;
  59 }
  60
  61 static bool
  62 convert_block(nir_block *block, void *state)
  63 {
  64    bool *progress = state;
  65
  66    nir_foreach_instr_safe(block, instr) {
  67       if (instr->type == nir_instr_type_intrinsic)
  68          *progress = convert_instr(nir_instr_as_intrinsic(instr)) || *progress;
  69    }
  70
  71    return true;
  72 }
  73
  74 static bool
  75 convert_impl(nir_function_impl *impl)
  76 {
  77    bool progress = false;
  78
  79    nir_foreach_block(impl, convert_block, &progress);
  80    nir_metadata_preserve(impl, nir_metadata_block_index |
  81                                nir_metadata_dominance);
  82    return progress;
  83 }
  84
  85 bool
  86 nir_lower_system_values(nir_shader *shader)
  87 {
  88    bool progress = false;
  89
  90    nir_foreach_overload(shader, overload) {
  91       if (overload->impl)
  92          progress = convert_impl(overload->impl) || progress;
  93    }
  94
  95    exec_list_make_empty(&shader->system_values);
  96
  97    return progress;
  98 }