src/glsl/nir/nir_lower_samplers.c

   1 /*
   2  * Copyright (C) 2005-2007  Brian Paul   All Rights Reserved.
   3  * Copyright (C) 2008  VMware, Inc.   All Rights Reserved.
   4  * Copyright © 2014 Intel Corporation
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice (including the next
  14  * paragraph) shall be included in all copies or substantial portions of the
  15  * Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  22  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  23  * DEALINGS IN THE SOFTWARE.
  24  */
  25
  26 #include "nir.h"
  27 #include "nir_builder.h"
  28 #include "../program.h"
  29 #include "program/hash_table.h"
  30 #include "ir_uniform.h"
  31
  32 #include "main/compiler.h"
  33 #include "main/mtypes.h"
  34 #include "program/prog_parameter.h"
  35 #include "program/program.h"
  36
  37 static void
  38 add_indirect_to_tex(nir_tex_instr *instr, nir_src indirect)
  39 {
  40    /* First, we have to resize the array of texture sources */
  41    nir_tex_src *new_srcs = rzalloc_array(instr, nir_tex_src,
  42                                          instr->num_srcs + 1);
  43
  44    for (unsigned i = 0; i < instr->num_srcs; i++) {
  45       new_srcs[i].src_type = instr->src[i].src_type;
  46       nir_instr_move_src(&instr->instr, &new_srcs[i].src, &instr->src[i].src);
  47    }
  48
  49    ralloc_free(instr->src);
  50    instr->src = new_srcs;
  51
  52    /* Now we can go ahead and move the source over to being a
  53     * first-class texture source.
  54     */
  55    instr->src[instr->num_srcs].src_type = nir_tex_src_sampler_offset;
  56    instr->num_srcs++;
  57    nir_instr_rewrite_src(&instr->instr, &instr->src[instr->num_srcs - 1].src,
  58                          indirect);
  59 }
  60
  61 /* Calculate the sampler index based on array indicies and also
  62  * calculate the base uniform location for struct members.
  63  */
  64 static void
  65 calc_sampler_offsets(nir_deref *tail, nir_tex_instr *instr,
  66                      unsigned *array_elements, nir_ssa_def **indirect,
  67                      nir_builder *b, unsigned *location)
  68 {
  69    if (tail->child == NULL)
  70       return;
  71
  72    switch (tail->child->deref_type) {
  73    case nir_deref_type_array: {
  74       nir_deref_array *deref_array = nir_deref_as_array(tail->child);
  75
  76       assert(deref_array->deref_array_type != nir_deref_array_type_wildcard);
  77
  78       calc_sampler_offsets(tail->child, instr, array_elements,
  79                            indirect, b, location);
  80       instr->sampler_index += deref_array->base_offset * *array_elements;
  81
  82       if (deref_array->deref_array_type == nir_deref_array_type_indirect) {
  83          nir_ssa_def *mul =
  84             nir_imul(b, nir_imm_int(b, *array_elements),
  85                      nir_ssa_for_src(b, deref_array->indirect, 1));
  86
  87          nir_instr_rewrite_src(&instr->instr, &deref_array->indirect,
  88                                NIR_SRC_INIT);
  89
  90          if (*indirect) {
  91             *indirect = nir_iadd(b, *indirect, mul);
  92          } else {
  93             *indirect = mul;
  94          }
  95       }
  96
  97       *array_elements *= glsl_get_length(tail->type);
  98        break;
  99    }
 100
 101    case nir_deref_type_struct: {
 102       nir_deref_struct *deref_struct = nir_deref_as_struct(tail->child);
 103       *location += glsl_get_record_location_offset(tail->type, deref_struct->index);
 104       calc_sampler_offsets(tail->child, instr, array_elements,
 105                            indirect, b, location);
 106       break;
 107    }
 108
 109    default:
 110       unreachable("Invalid deref type");
 111       break;
 112    }
 113 }
 114
 115 static void
 116 lower_sampler(nir_tex_instr *instr, const struct gl_shader_program *shader_program,
 117               gl_shader_stage stage, nir_builder *builder)
 118 {
 119    if (instr->sampler == NULL)
 120       return;
 121
 122    instr->sampler_index = 0;
 123    unsigned location = instr->sampler->var->data.location;
 124    unsigned array_elements = 1;
 125    nir_ssa_def *indirect = NULL;
 126
 127    builder->cursor = nir_before_instr(&instr->instr);
 128    calc_sampler_offsets(&instr->sampler->deref, instr, &array_elements,
 129                         &indirect, builder, &location);
 130
 131    if (indirect) {
 132       /* First, we have to resize the array of texture sources */
 133       nir_tex_src *new_srcs = rzalloc_array(instr, nir_tex_src,
 134                                             instr->num_srcs + 1);
 135
 136       for (unsigned i = 0; i < instr->num_srcs; i++) {
 137          new_srcs[i].src_type = instr->src[i].src_type;
 138          nir_instr_move_src(&instr->instr, &new_srcs[i].src,
 139                             &instr->src[i].src);
 140       }
 141
 142       ralloc_free(instr->src);
 143       instr->src = new_srcs;
 144
 145       /* Now we can go ahead and move the source over to being a
 146        * first-class texture source.
 147        */
 148       instr->src[instr->num_srcs].src_type = nir_tex_src_sampler_offset;
 149       instr->num_srcs++;
 150       nir_instr_rewrite_src(&instr->instr,
 151                             &instr->src[instr->num_srcs - 1].src,
 152                             nir_src_for_ssa(indirect));
 153
 154       instr->sampler_array_size = array_elements;
 155    }
 156
 157    if (location > shader_program->NumUniformStorage - 1 ||
 158        !shader_program->UniformStorage[location].opaque[stage].active) {
 159       assert(!"cannot return a sampler");
 160       return;
 161    }
 162
 163    instr->sampler_index +=
 164       shader_program->UniformStorage[location].opaque[stage].index;
 165
 166    instr->sampler = NULL;
 167 }
 168
 169 typedef struct {
 170    nir_builder builder;
 171    const struct gl_shader_program *shader_program;
 172    gl_shader_stage stage;
 173 } lower_state;
 174
 175 static bool
 176 lower_block_cb(nir_block *block, void *_state)
 177 {
 178    lower_state *state = (lower_state *) _state;
 179
 180    nir_foreach_instr(block, instr) {
 181       if (instr->type == nir_instr_type_tex) {
 182          nir_tex_instr *tex_instr = nir_instr_as_tex(instr);
 183          lower_sampler(tex_instr, state->shader_program, state->stage,
 184                        &state->builder);
 185       }
 186    }
 187
 188    return true;
 189 }
 190
 191 static void
 192 lower_impl(nir_function_impl *impl, const struct gl_shader_program *shader_program,
 193            gl_shader_stage stage)
 194 {
 195    lower_state state;
 196
 197    nir_builder_init(&state.builder, impl);
 198    state.shader_program = shader_program;
 199    state.stage = stage;
 200
 201    nir_foreach_block(impl, lower_block_cb, &state);
 202 }
 203
 204 void
 205 nir_lower_samplers(nir_shader *shader,
 206                    const struct gl_shader_program *shader_program)
 207 {
 208    nir_foreach_overload(shader, overload) {
 209       if (overload->impl)
 210          lower_impl(overload->impl, shader_program, shader->stage);
 211    }
 212 }
 213
 214 static bool
 215 lower_samplers_for_vk_block(nir_block *block, void *data)
 216 {
 217    nir_foreach_instr(block, instr) {
 218       if (instr->type != nir_instr_type_tex)
 219          continue;
 220
 221       nir_tex_instr *tex = nir_instr_as_tex(instr);
 222
 223       assert(tex->sampler);
 224
 225       tex->sampler_set = tex->sampler->var->data.descriptor_set;
 226       tex->sampler_index = tex->sampler->var->data.binding;
 227
 228       if (tex->sampler->deref.child) {
 229          assert(tex->sampler->deref.child->deref_type == nir_deref_type_array);
 230          nir_deref_array *arr = nir_deref_as_array(tex->sampler->deref.child);
 231
 232          /* Only one-level arrays are allowed in vulkan */
 233          assert(arr->deref.child == NULL);
 234
 235          tex->sampler_index += arr->base_offset;
 236          if (arr->deref_array_type == nir_deref_array_type_indirect) {
 237             add_indirect_to_tex(tex, arr->indirect);
 238             nir_instr_rewrite_src(instr, &arr->indirect, NIR_SRC_INIT);
 239
 240             tex->sampler_array_size = glsl_get_length(tex->sampler->deref.type);
 241          }
 242       }
 243
 244       tex->sampler = NULL;
 245    }
 246
 247    return true;
 248 }
 249
 250 void
 251 nir_lower_samplers_for_vk(nir_shader *shader)
 252 {
 253    nir_foreach_overload(shader, overload) {
 254       if (overload->impl) {
 255          nir_foreach_block(overload->impl, lower_samplers_for_vk_block, NULL);
 256       }
 257    }
 258 }