src/gallium/drivers/freedreno/ir3/ir3_nir_lower_tg4_to_tex.c

   1 /*
   2  * Copyright © 2017 Ilia Mirkin
   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 "ir3_nir.h"
  25 #include "compiler/nir/nir_builder.h"
  26
  27 /* A4XX has a broken GATHER4 operation. It performs the texture swizzle on the
  28  * gather results, rather than before. As a result, it must be emulated with
  29  * direct texture calls.
  30  */
  31
  32 static bool
  33 lower_tg4(nir_block *block, nir_builder *b, void *mem_ctx)
  34 {
  35         bool progress = false;
  36
  37         static const int offsets[3][2] = { {0, 1}, {1, 1}, {1, 0} };
  38
  39         nir_foreach_instr_safe(instr, block) {
  40                 if (instr->type != nir_instr_type_tex)
  41                         continue;
  42
  43         nir_tex_instr *tg4 = (nir_tex_instr *)instr;
  44
  45                 if (tg4->op != nir_texop_tg4)
  46                         continue;
  47
  48                 b->cursor = nir_before_instr(&tg4->instr);
  49
  50                 nir_ssa_def *results[4];
  51                 int offset_index = nir_tex_instr_src_index(tg4, nir_tex_src_offset);
  52                 for (int i = 0; i < 4; i++) {
  53                         int num_srcs = tg4->num_srcs + 1 /* lod */;
  54                         if (offset_index < 0 && i < 3)
  55                                 num_srcs++;
  56
  57                         nir_tex_instr *tex = nir_tex_instr_create(b->shader, num_srcs);
  58                         tex->op = nir_texop_txl;
  59                         tex->sampler_dim = tg4->sampler_dim;
  60                         tex->coord_components = tg4->coord_components;
  61                         tex->is_array = tg4->is_array;
  62                         tex->is_shadow = tg4->is_shadow;
  63                         tex->is_new_style_shadow = tg4->is_new_style_shadow;
  64                         tex->texture_index = tg4->texture_index;
  65                         tex->texture = nir_deref_var_clone(tg4->texture, tex);
  66                         tex->sampler_index = tg4->sampler_index;
  67                         tex->sampler = nir_deref_var_clone(tg4->sampler, tex);
  68                         tex->dest_type = tg4->dest_type;
  69
  70                         for (int j = 0; j < tg4->num_srcs; j++) {
  71                                 nir_src_copy(&tex->src[j].src, &tg4->src[j].src, tex);
  72                                 tex->src[j].src_type = tg4->src[j].src_type;
  73                         }
  74                         if (i != 3) {
  75                                 nir_ssa_def *offset =
  76                                         nir_vec2(b, nir_imm_int(b, offsets[i][0]),
  77                                                          nir_imm_int(b, offsets[i][1]));
  78                                 if (offset_index < 0) {
  79                                         tex->src[tg4->num_srcs].src = nir_src_for_ssa(offset);
  80                                         tex->src[tg4->num_srcs].src_type = nir_tex_src_offset;
  81                                 } else {
  82                                         assert(nir_tex_instr_src_size(tex, offset_index) == 2);
  83                                         nir_ssa_def *orig = nir_ssa_for_src(
  84                                                         b, tex->src[offset_index].src, 2);
  85                                         tex->src[offset_index].src =
  86                                                 nir_src_for_ssa(nir_iadd(b, orig, offset));
  87                                 }
  88                         }
  89                         tex->src[num_srcs - 1].src = nir_src_for_ssa(nir_imm_float(b, 0));
  90                         tex->src[num_srcs - 1].src_type = nir_tex_src_lod;
  91
  92                         nir_ssa_dest_init(&tex->instr, &tex->dest,
  93                                                           nir_tex_instr_dest_size(tex), 32, NULL);
  94                         nir_builder_instr_insert(b, &tex->instr);
  95
  96                         results[i] = nir_channel(b, &tex->dest.ssa, tg4->component);
  97                 }
  98
  99                 nir_ssa_def *result = nir_vec4(b, results[0], results[1], results[2], results[3]);
 100                 nir_ssa_def_rewrite_uses(&tg4->dest.ssa, nir_src_for_ssa(result));
 101
 102                 nir_instr_remove(&tg4->instr);
 103
 104                 progress = true;
 105         }
 106
 107         return progress;
 108 }
 109
 110 static bool
 111 lower_tg4_func(nir_function_impl *impl)
 112 {
 113         void *mem_ctx = ralloc_parent(impl);
 114         nir_builder b;
 115         nir_builder_init(&b, impl);
 116
 117         bool progress = false;
 118         nir_foreach_block_safe(block, impl) {
 119                 progress |= lower_tg4(block, &b, mem_ctx);
 120         }
 121
 122         if (progress)
 123                 nir_metadata_preserve(impl, nir_metadata_block_index |
 124                                                                         nir_metadata_dominance);
 125
 126         return progress;
 127 }
 128
 129 bool
 130 ir3_nir_lower_tg4_to_tex(nir_shader *shader)
 131 {
 132         bool progress = false;
 133
 134         nir_foreach_function(function, shader) {
 135                 if (function->impl)
 136                         progress |= lower_tg4_func(function->impl);
 137         }
 138
 139         return progress;
 140 }