src/compiler/nir/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 "nir.h"
  25 #include "nir_builder.h"
  26
  27 static nir_ssa_def *
  28 load_frag_coord(const nir_input_attachment_options *options, nir_builder *b)
  29 {
  30    if (options->use_fragcoord_sysval)
  31       return nir_load_frag_coord(b);
  32
  33    nir_variable *pos =
  34       nir_find_variable_with_location(b->shader, nir_var_shader_in,
  35                                       VARYING_SLOT_POS);
  36    if (pos == NULL) {
  37       pos = nir_variable_create(b->shader, nir_var_shader_in,
  38                                 glsl_vec4_type(), NULL);
  39       pos->data.location = VARYING_SLOT_POS;
  40    }
  41    /**
  42     * From Vulkan spec:
  43     *   "The OriginLowerLeft execution mode must not be used; fragment entry
  44     *    points must declare OriginUpperLeft."
  45     *
  46     * So at this point origin_upper_left should be true
  47     */
  48    assert(b->shader->info.fs.origin_upper_left == true);
  49
  50    return nir_load_var(b, pos);
  51 }
  52
  53 static bool
  54 try_lower_input_load(nir_function_impl *impl, nir_intrinsic_instr *load,
  55                      const nir_input_attachment_options *options)
  56 {
  57    nir_deref_instr *deref = nir_src_as_deref(load->src[0]);
  58    assert(glsl_type_is_image(deref->type));
  59
  60    enum glsl_sampler_dim image_dim = glsl_get_sampler_dim(deref->type);
  61    if (image_dim != GLSL_SAMPLER_DIM_SUBPASS &&
  62        image_dim != GLSL_SAMPLER_DIM_SUBPASS_MS)
  63       return false;
  64
  65    const bool multisampled = (image_dim == GLSL_SAMPLER_DIM_SUBPASS_MS);
  66
  67    nir_builder b;
  68    nir_builder_init(&b, impl);
  69    b.cursor = nir_instr_remove(&load->instr);
  70
  71    nir_ssa_def *frag_coord = load_frag_coord(options, &b);
  72    frag_coord = nir_f2i32(&b, frag_coord);
  73    nir_ssa_def *offset = nir_ssa_for_src(&b, load->src[1], 2);
  74    nir_ssa_def *pos = nir_iadd(&b, frag_coord, offset);
  75
  76    nir_ssa_def *layer = nir_load_layer_id(&b);
  77    nir_ssa_def *coord =
  78       nir_vec3(&b, nir_channel(&b, pos, 0), nir_channel(&b, pos, 1), layer);
  79
  80    nir_tex_instr *tex = nir_tex_instr_create(b.shader, 3 + multisampled);
  81
  82    tex->op = nir_texop_txf;
  83    tex->sampler_dim = image_dim;
  84
  85    switch (glsl_get_sampler_result_type(deref->type)) {
  86    case GLSL_TYPE_FLOAT:
  87       tex->dest_type = nir_type_float;
  88       break;
  89    case GLSL_TYPE_INT:
  90       tex->dest_type = nir_type_int;
  91       break;
  92    case GLSL_TYPE_UINT:
  93       tex->dest_type = nir_type_uint;
  94       break;
  95    default:
  96       unreachable("Invalid image type");
  97    }
  98    tex->is_array = true;
  99    tex->is_shadow = false;
 100
 101    tex->texture_index = 0;
 102    tex->sampler_index = 0;
 103
 104    tex->src[0].src_type = nir_tex_src_texture_deref;
 105    tex->src[0].src = nir_src_for_ssa(&deref->dest.ssa);
 106
 107    tex->src[1].src_type = nir_tex_src_coord;
 108    tex->src[1].src = nir_src_for_ssa(coord);
 109    tex->coord_components = 3;
 110
 111    tex->src[2].src_type = nir_tex_src_lod;
 112    tex->src[2].src = nir_src_for_ssa(nir_imm_int(&b, 0));
 113
 114    if (image_dim == GLSL_SAMPLER_DIM_SUBPASS_MS) {
 115       tex->op = nir_texop_txf_ms;
 116       tex->src[3].src_type = nir_tex_src_ms_index;
 117       tex->src[3].src = load->src[2];
 118    }
 119
 120    tex->texture_non_uniform = nir_intrinsic_access(load) & ACCESS_NON_UNIFORM;
 121
 122    nir_ssa_dest_init(&tex->instr, &tex->dest, 4, 32, NULL);
 123    nir_builder_instr_insert(&b, &tex->instr);
 124
 125    nir_ssa_def_rewrite_uses(&load->dest.ssa,
 126                             nir_src_for_ssa(&tex->dest.ssa));
 127
 128    return true;
 129 }
 130
 131 static bool
 132 try_lower_input_texop(nir_function_impl *impl, nir_tex_instr *tex,
 133                       const nir_input_attachment_options *options)
 134 {
 135    nir_deref_instr *deref = nir_src_as_deref(tex->src[0].src);
 136
 137    if (glsl_get_sampler_dim(deref->type) != GLSL_SAMPLER_DIM_SUBPASS_MS)
 138       return false;
 139
 140    nir_builder b;
 141    nir_builder_init(&b, impl);
 142    b.cursor = nir_before_instr(&tex->instr);
 143
 144    nir_ssa_def *frag_coord = load_frag_coord(options, &b);
 145    frag_coord = nir_f2i32(&b, frag_coord);
 146
 147    nir_ssa_def *layer = nir_load_layer_id(&b);
 148    nir_ssa_def *coord = nir_vec3(&b, nir_channel(&b, frag_coord, 0),
 149                                      nir_channel(&b, frag_coord, 1), layer);
 150
 151    tex->coord_components = 3;
 152
 153    nir_instr_rewrite_src(&tex->instr, &tex->src[1].src, nir_src_for_ssa(coord));
 154
 155    return true;
 156 }
 157
 158 bool
 159 nir_lower_input_attachments(nir_shader *shader,
 160                             const nir_input_attachment_options *options)
 161 {
 162    assert(shader->info.stage == MESA_SHADER_FRAGMENT);
 163    bool progress = false;
 164
 165    nir_foreach_function(function, shader) {
 166       if (!function->impl)
 167          continue;
 168
 169       nir_foreach_block(block, function->impl) {
 170          nir_foreach_instr_safe(instr, block) {
 171             switch (instr->type) {
 172             case nir_instr_type_tex: {
 173                nir_tex_instr *tex = nir_instr_as_tex(instr);
 174
 175                if (tex->op == nir_texop_fragment_mask_fetch ||
 176                    tex->op == nir_texop_fragment_fetch) {
 177                   progress |= try_lower_input_texop(function->impl, tex,
 178                                                     options);
 179                }
 180                break;
 181             }
 182             case nir_instr_type_intrinsic: {
 183                nir_intrinsic_instr *load = nir_instr_as_intrinsic(instr);
 184
 185                if (load->intrinsic == nir_intrinsic_image_deref_load) {
 186                   progress |= try_lower_input_load(function->impl, load,
 187                                                    options);
 188                }
 189                break;
 190             }
 191             default:
 192                break;
 193             }
 194          }
 195       }
 196    }
 197
 198    return progress;
 199 }