src/intel/vulkan/anv_nir_lower_input_attachments.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 "anv_nir.h"
  25 #include "nir/nir_builder.h"
  26
  27 static nir_ssa_def *
  28 load_frag_coord(nir_builder *b)
  29 {
  30    nir_foreach_variable(var, &b->shader->inputs) {
  31       if (var->data.location == VARYING_SLOT_POS)
  32          return nir_load_var(b, var);
  33    }
  34
  35    nir_variable *pos = nir_variable_create(b->shader, nir_var_shader_in,
  36                                            glsl_vec4_type(), NULL);
  37    pos->data.location = VARYING_SLOT_POS;
  38    pos->data.origin_upper_left = true;
  39
  40    return nir_load_var(b, pos);
  41 }
  42
  43 static void
  44 try_lower_input_load(nir_function_impl *impl, nir_intrinsic_instr *load)
  45 {
  46
  47    const struct glsl_type *image_type =
  48       glsl_without_array(load->variables[0]->var->type);
  49    enum glsl_sampler_dim image_dim = glsl_get_sampler_dim(image_type);
  50    if (image_dim != GLSL_SAMPLER_DIM_SUBPASS &&
  51        image_dim != GLSL_SAMPLER_DIM_SUBPASS_MS)
  52       return;
  53
  54    const bool multisampled = (image_dim == GLSL_SAMPLER_DIM_SUBPASS_MS);
  55
  56    nir_builder b;
  57    nir_builder_init(&b, impl);
  58    b.cursor = nir_before_instr(&load->instr);
  59
  60    nir_ssa_def *frag_coord = nir_f2i(&b, load_frag_coord(&b));
  61    nir_ssa_def *offset = nir_ssa_for_src(&b, load->src[0], 2);
  62    nir_ssa_def *pos = nir_iadd(&b, frag_coord, offset);
  63
  64    nir_ssa_def *layer =
  65       nir_load_system_value(&b, nir_intrinsic_load_layer_id, 0);
  66    nir_ssa_def *coord =
  67       nir_vec3(&b, nir_channel(&b, pos, 0), nir_channel(&b, pos, 1), layer);
  68
  69    nir_tex_instr *tex = nir_tex_instr_create(b.shader, 2 + multisampled);
  70
  71    tex->op = nir_texop_txf;
  72
  73    switch (glsl_get_sampler_result_type(image_type)) {
  74    case GLSL_TYPE_FLOAT:
  75       tex->dest_type = nir_type_float;
  76       break;
  77    case GLSL_TYPE_INT:
  78       tex->dest_type = nir_type_int;
  79       break;
  80    case GLSL_TYPE_UINT:
  81       tex->dest_type = nir_type_uint;
  82       break;
  83    default:
  84       unreachable("Invalid image type");
  85    }
  86    tex->is_array = true;
  87    tex->is_shadow = false;
  88
  89    tex->texture = nir_deref_var_clone(load->variables[0], tex);
  90    tex->sampler = NULL;
  91    tex->texture_index = 0;
  92    tex->sampler_index = 0;
  93
  94    tex->src[0].src_type = nir_tex_src_coord;
  95    tex->src[0].src = nir_src_for_ssa(coord);
  96    tex->coord_components = 3;
  97
  98    tex->src[1].src_type = nir_tex_src_lod;
  99    tex->src[1].src = nir_src_for_ssa(nir_imm_int(&b, 0));
 100
 101    if (image_dim == GLSL_SAMPLER_DIM_SUBPASS_MS) {
 102       tex->op = nir_texop_txf_ms;
 103
 104       nir_ssa_def *sample_id =
 105          nir_load_system_value(&b, nir_intrinsic_load_sample_id, 0);
 106       tex->src[2].src_type = nir_tex_src_ms_index;
 107       tex->src[2].src = nir_src_for_ssa(sample_id);
 108    }
 109
 110    nir_ssa_dest_init(&tex->instr, &tex->dest, 4, 32, NULL);
 111    nir_builder_instr_insert(&b, &tex->instr);
 112
 113    nir_ssa_def_rewrite_uses(&load->dest.ssa,
 114                             nir_src_for_ssa(&tex->dest.ssa));
 115 }
 116
 117 void
 118 anv_nir_lower_input_attachments(nir_shader *shader)
 119 {
 120    assert(shader->stage == MESA_SHADER_FRAGMENT);
 121
 122    nir_foreach_function(function, shader) {
 123       if (!function->impl)
 124          continue;
 125
 126       nir_foreach_block(block, function->impl) {
 127          nir_foreach_instr(instr, block) {
 128             if (instr->type != nir_instr_type_intrinsic)
 129                continue;
 130
 131             nir_intrinsic_instr *load = nir_instr_as_intrinsic(instr);
 132
 133             if (load->intrinsic != nir_intrinsic_image_load)
 134                continue;
 135
 136             try_lower_input_load(function->impl, load);
 137          }
 138       }
 139    }
 140 }