src/glsl/nir/nir_lower_samplers.cpp

   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 "../program.h"
  28 #include "program/hash_table.h"
  29 #include "ir_uniform.h"
  30
  31 extern "C" {
  32 #include "main/compiler.h"
  33 #include "main/mtypes.h"
  34 #include "program/prog_parameter.h"
  35 #include "program/program.h"
  36 }
  37
  38 static unsigned
  39 get_sampler_index(struct gl_shader_program *shader_program,
  40                   gl_shader_stage stage, const char *name)
  41 {
  42    unsigned location;
  43    if (!shader_program->UniformHash->get(location, name)) {
  44       linker_error(shader_program,
  45                    "failed to find sampler named %s.\n", name);
  46       return 0;
  47    }
  48
  49    if (!shader_program->UniformStorage[location].sampler[stage].active) {
  50       assert(0 && "cannot return a sampler");
  51       linker_error(shader_program,
  52                    "cannot return a sampler named %s, because it is not "
  53                    "used in this shader stage. This is a driver bug.\n",
  54                    name);
  55       return 0;
  56    }
  57
  58    return shader_program->UniformStorage[location].sampler[stage].index;
  59 }
  60
  61 static void
  62 lower_sampler(nir_tex_instr *instr, struct gl_shader_program *shader_program,
  63               gl_shader_stage stage, void *mem_ctx)
  64 {
  65    if (instr->sampler == NULL)
  66       return;
  67
  68    /* Get the name and the offset */
  69    instr->sampler_index = 0;
  70    char *name = ralloc_strdup(mem_ctx, instr->sampler->var->name);
  71
  72    for (nir_deref *deref = &instr->sampler->deref;
  73         deref->child; deref = deref->child) {
  74       switch (deref->child->deref_type) {
  75       case nir_deref_type_array: {
  76          nir_deref_array *deref_array = nir_deref_as_array(deref->child);
  77
  78          /* XXX: We're assuming here that the indirect is the last array
  79           * thing we have.  This should be ok for now as we don't support
  80           * arrays_of_arrays yet.
  81           */
  82
  83          instr->sampler_index *= glsl_get_length(deref->type);
  84          switch (deref_array->deref_array_type) {
  85          case nir_deref_array_type_direct:
  86             instr->sampler_index += deref_array->base_offset;
  87             if (deref_array->deref.child)
  88                ralloc_asprintf_append(&name, "[%u]", deref_array->base_offset);
  89             break;
  90          case nir_deref_array_type_indirect: {
  91             instr->src = reralloc(instr, instr->src, nir_tex_src,
  92                                   instr->num_srcs + 1);
  93             memset(&instr->src[instr->num_srcs], 0, sizeof *instr->src);
  94             instr->src[instr->num_srcs].src_type = nir_tex_src_sampler_offset;
  95             instr->num_srcs++;
  96
  97             nir_instr_rewrite_src(&instr->instr,
  98                                   &instr->src[instr->num_srcs - 1].src,
  99                                   deref_array->indirect);
 100
 101             instr->sampler_array_size = glsl_get_length(deref->type);
 102
 103             nir_src empty;
 104             memset(&empty, 0, sizeof empty);
 105             nir_instr_rewrite_src(&instr->instr, &deref_array->indirect, empty);
 106
 107             if (deref_array->deref.child)
 108                ralloc_strcat(&name, "[0]");
 109             break;
 110          }
 111
 112          case nir_deref_array_type_wildcard:
 113             unreachable("Cannot copy samplers");
 114          default:
 115             unreachable("Invalid deref array type");
 116          }
 117          break;
 118       }
 119
 120       case nir_deref_type_struct: {
 121          nir_deref_struct *deref_struct = nir_deref_as_struct(deref->child);
 122          const char *field = glsl_get_struct_elem_name(deref->type,
 123                                                        deref_struct->index);
 124          ralloc_asprintf_append(&name, ".%s", field);
 125          break;
 126       }
 127
 128       default:
 129          unreachable("Invalid deref type");
 130          break;
 131       }
 132    }
 133
 134    instr->sampler_index += get_sampler_index(shader_program, stage, name);
 135
 136    instr->sampler = NULL;
 137 }
 138
 139 typedef struct {
 140    void *mem_ctx;
 141    struct gl_shader_program *shader_program;
 142    gl_shader_stage stage;
 143 } lower_state;
 144
 145 static bool
 146 lower_block_cb(nir_block *block, void *_state)
 147 {
 148    lower_state *state = (lower_state *) _state;
 149
 150    nir_foreach_instr(block, instr) {
 151       if (instr->type == nir_instr_type_tex) {
 152          nir_tex_instr *tex_instr = nir_instr_as_tex(instr);
 153          lower_sampler(tex_instr, state->shader_program, state->stage,
 154                        state->mem_ctx);
 155       }
 156    }
 157
 158    return true;
 159 }
 160
 161 static void
 162 lower_impl(nir_function_impl *impl, struct gl_shader_program *shader_program,
 163            gl_shader_stage stage)
 164 {
 165    lower_state state;
 166
 167    state.mem_ctx = ralloc_parent(impl);
 168    state.shader_program = shader_program;
 169    state.stage = stage;
 170
 171    nir_foreach_block(impl, lower_block_cb, &state);
 172 }
 173
 174 extern "C" void
 175 nir_lower_samplers(nir_shader *shader, struct gl_shader_program *shader_program,
 176                    gl_shader_stage stage)
 177 {
 178    nir_foreach_overload(shader, overload) {
 179       if (overload->impl)
 180          lower_impl(overload->impl, shader_program, stage);
 181    }
 182 }