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 void
  32 convert_instr(nir_intrinsic_instr *instr)
  33 {
  34    if (instr->intrinsic != nir_intrinsic_load_var)
  35       return;
  36
  37    nir_variable *var = instr->variables[0]->var;
  38    if (var->data.mode != nir_var_system_value)
  39       return;
  40
  41    void *mem_ctx = ralloc_parent(instr);
  42
  43    nir_intrinsic_op op;
  44
  45    switch (var->data.location) {
  46    case SYSTEM_VALUE_FRONT_FACE:
  47       op = nir_intrinsic_load_front_face;
  48       break;
  49    case SYSTEM_VALUE_VERTEX_ID:
  50       op = nir_intrinsic_load_vertex_id;
  51       break;
  52    case SYSTEM_VALUE_VERTEX_ID_ZERO_BASE:
  53       op = nir_intrinsic_load_vertex_id_zero_base;
  54       break;
  55    case SYSTEM_VALUE_BASE_VERTEX:
  56       op = nir_intrinsic_load_base_vertex;
  57       break;
  58    case SYSTEM_VALUE_INSTANCE_ID:
  59       op = nir_intrinsic_load_instance_id;
  60       break;
  61    case SYSTEM_VALUE_SAMPLE_ID:
  62       op = nir_intrinsic_load_sample_id;
  63       break;
  64    case SYSTEM_VALUE_SAMPLE_POS:
  65       op = nir_intrinsic_load_sample_pos;
  66       break;
  67    case SYSTEM_VALUE_SAMPLE_MASK_IN:
  68       op = nir_intrinsic_load_sample_mask_in;
  69       break;
  70    case SYSTEM_VALUE_INVOCATION_ID:
  71       op = nir_intrinsic_load_invocation_id;
  72       break;
  73    default:
  74       unreachable("not reached");
  75    }
  76
  77    nir_intrinsic_instr *new_instr = nir_intrinsic_instr_create(mem_ctx, op);
  78
  79    if (instr->dest.is_ssa) {
  80       nir_ssa_dest_init(&new_instr->instr, &new_instr->dest,
  81                         instr->dest.ssa.num_components, NULL);
  82       nir_ssa_def_rewrite_uses(&instr->dest.ssa,
  83                                nir_src_for_ssa(&new_instr->dest.ssa),
  84                                mem_ctx);
  85    } else {
  86       nir_dest_copy(&new_instr->dest, &instr->dest, mem_ctx);
  87    }
  88
  89    nir_instr_insert_before(&instr->instr, &new_instr->instr);
  90    nir_instr_remove(&instr->instr);
  91 }
  92
  93 static bool
  94 convert_block(nir_block *block, void *state)
  95 {
  96    (void) state;
  97
  98    nir_foreach_instr_safe(block, instr) {
  99       if (instr->type == nir_instr_type_intrinsic)
 100          convert_instr(nir_instr_as_intrinsic(instr));
 101    }
 102
 103    return true;
 104 }
 105
 106 static void
 107 convert_impl(nir_function_impl *impl)
 108 {
 109    nir_foreach_block(impl, convert_block, NULL);
 110    nir_metadata_preserve(impl, nir_metadata_block_index |
 111                                nir_metadata_dominance);
 112 }
 113
 114 void
 115 nir_lower_system_values(nir_shader *shader)
 116 {
 117    nir_foreach_overload(shader, overload) {
 118       if (overload->impl)
 119          convert_impl(overload->impl);
 120    }
 121
 122    exec_list_make_empty(&shader->system_values);
 123 }