src/gallium/frontends/vallium/val_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 #include "val_lower_vulkan_resource.h"
  27
  28 static nir_ssa_def *
  29 load_frag_coord(nir_builder *b)
  30 {
  31    nir_variable *pos =
  32       nir_find_variable_with_location(b->shader, nir_var_shader_in,
  33                                       VARYING_SLOT_POS);
  34    if (pos == NULL) {
  35       pos = nir_variable_create(b->shader, nir_var_shader_in,
  36                                            glsl_vec4_type(), NULL);
  37       pos->data.location = VARYING_SLOT_POS;
  38    }
  39    /**
  40     * From Vulkan spec:
  41     *   "The OriginLowerLeft execution mode must not be used; fragment entry
  42     *    points must declare OriginUpperLeft."
  43     *
  44     * So at this point origin_upper_left should be true
  45     */
  46    assert(b->shader->info.fs.origin_upper_left == true);
  47
  48    return nir_load_var(b, pos);
  49 }
  50
  51 static bool
  52 try_lower_input_load(nir_function_impl *impl, nir_intrinsic_instr *load,
  53                      bool use_fragcoord_sysval)
  54 {
  55    nir_deref_instr *deref = nir_src_as_deref(load->src[0]);
  56    assert(glsl_type_is_image(deref->type));
  57
  58    enum glsl_sampler_dim image_dim = glsl_get_sampler_dim(deref->type);
  59    if (image_dim != GLSL_SAMPLER_DIM_SUBPASS &&
  60        image_dim != GLSL_SAMPLER_DIM_SUBPASS_MS)
  61       return false;
  62
  63    nir_builder b;
  64    nir_builder_init(&b, impl);
  65    b.cursor = nir_before_instr(&load->instr);
  66
  67    nir_ssa_def *frag_coord = use_fragcoord_sysval ? nir_load_frag_coord(&b)
  68                                                   : load_frag_coord(&b);
  69    frag_coord = nir_f2i32(&b, frag_coord);
  70    nir_ssa_def *offset = nir_ssa_for_src(&b, load->src[1], 2);
  71    nir_ssa_def *pos = nir_iadd(&b, frag_coord, offset);
  72
  73    nir_ssa_def *layer = nir_imm_int(&b, 0);
  74    nir_ssa_def *coord =
  75       nir_vec4(&b, nir_channel(&b, pos, 0), nir_channel(&b, pos, 1), layer, layer);
  76
  77    nir_instr_rewrite_src(&load->instr, &load->src[1], nir_src_for_ssa(coord));
  78
  79    return true;
  80 }
  81
  82 bool
  83 val_lower_input_attachments(nir_shader *shader, bool use_fragcoord_sysval)
  84 {
  85    assert(shader->info.stage == MESA_SHADER_FRAGMENT);
  86    bool progress = false;
  87
  88    nir_foreach_function(function, shader) {
  89       if (!function->impl)
  90          continue;
  91
  92       nir_foreach_block(block, function->impl) {
  93          nir_foreach_instr_safe(instr, block) {
  94             if (instr->type != nir_instr_type_intrinsic)
  95                continue;
  96
  97             nir_intrinsic_instr *load = nir_instr_as_intrinsic(instr);
  98
  99             if (load->intrinsic != nir_intrinsic_image_deref_load)
 100                continue;
 101
 102             progress |= try_lower_input_load(function->impl, load,
 103                                              use_fragcoord_sysval);
 104          }
 105       }
 106    }
 107
 108    return progress;
 109 }