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(const 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       assert(!"failed to find sampler");
  45       return 0;
  46    }
  47
  48    if (!shader_program->UniformStorage[location].sampler[stage].active) {
  49       assert(!"cannot return a sampler");
  50       return 0;
  51    }
  52
  53    return shader_program->UniformStorage[location].sampler[stage].index;
  54 }
  55
  56 static void
  57 lower_sampler(nir_tex_instr *instr, const struct gl_shader_program *shader_program,
  58               gl_shader_stage stage, void *mem_ctx)
  59 {
  60    if (instr->sampler == NULL)
  61       return;
  62
  63    /* Get the name and the offset */
  64    instr->sampler_index = 0;
  65    char *name = ralloc_strdup(mem_ctx, instr->sampler->var->name);
  66
  67    for (nir_deref *deref = &instr->sampler->deref;
  68         deref->child; deref = deref->child) {
  69       switch (deref->child->deref_type) {
  70       case nir_deref_type_array: {
  71          nir_deref_array *deref_array = nir_deref_as_array(deref->child);
  72
  73          assert(deref_array->deref_array_type != nir_deref_array_type_wildcard);
  74
  75          if (deref_array->deref.child) {
  76             ralloc_asprintf_append(&name, "[%u]",
  77                deref_array->deref_array_type == nir_deref_array_type_direct ?
  78                   deref_array->base_offset : 0);
  79          } else {
  80             assert(deref->child->type->base_type == GLSL_TYPE_SAMPLER);
  81             instr->sampler_index = deref_array->base_offset;
  82          }
  83
  84          /* XXX: We're assuming here that the indirect is the last array
  85           * thing we have.  This should be ok for now as we don't support
  86           * arrays_of_arrays yet.
  87           */
  88          if (deref_array->deref_array_type == nir_deref_array_type_indirect) {
  89             /* First, we have to resize the array of texture sources */
  90             nir_tex_src *new_srcs = rzalloc_array(instr, nir_tex_src,
  91                                                   instr->num_srcs + 1);
  92
  93             for (unsigned i = 0; i < instr->num_srcs; i++) {
  94                new_srcs[i].src_type = instr->src[i].src_type;
  95                nir_instr_move_src(&instr->instr, &new_srcs[i].src,
  96                                   &instr->src[i].src);
  97             }
  98
  99             ralloc_free(instr->src);
 100             instr->src = new_srcs;
 101
 102             /* Now we can go ahead and move the source over to being a
 103              * first-class texture source.
 104              */
 105             instr->src[instr->num_srcs].src_type = nir_tex_src_sampler_offset;
 106             instr->num_srcs++;
 107             nir_instr_move_src(&instr->instr,
 108                                &instr->src[instr->num_srcs - 1].src,
 109                                &deref_array->indirect);
 110
 111             instr->sampler_array_size = glsl_get_length(deref->type);
 112          }
 113          break;
 114       }
 115
 116       case nir_deref_type_struct: {
 117          nir_deref_struct *deref_struct = nir_deref_as_struct(deref->child);
 118          const char *field = glsl_get_struct_elem_name(deref->type,
 119                                                        deref_struct->index);
 120          ralloc_asprintf_append(&name, ".%s", field);
 121          break;
 122       }
 123
 124       default:
 125          unreachable("Invalid deref type");
 126          break;
 127       }
 128    }
 129
 130    instr->sampler_index += get_sampler_index(shader_program, stage, name);
 131
 132    instr->sampler = NULL;
 133 }
 134
 135 typedef struct {
 136    void *mem_ctx;
 137    const struct gl_shader_program *shader_program;
 138    gl_shader_stage stage;
 139 } lower_state;
 140
 141 static bool
 142 lower_block_cb(nir_block *block, void *_state)
 143 {
 144    lower_state *state = (lower_state *) _state;
 145
 146    nir_foreach_instr(block, instr) {
 147       if (instr->type == nir_instr_type_tex) {
 148          nir_tex_instr *tex_instr = nir_instr_as_tex(instr);
 149          lower_sampler(tex_instr, state->shader_program, state->stage,
 150                        state->mem_ctx);
 151       }
 152    }
 153
 154    return true;
 155 }
 156
 157 static void
 158 lower_impl(nir_function_impl *impl, const struct gl_shader_program *shader_program,
 159            gl_shader_stage stage)
 160 {
 161    lower_state state;
 162
 163    state.mem_ctx = ralloc_parent(impl);
 164    state.shader_program = shader_program;
 165    state.stage = stage;
 166
 167    nir_foreach_block(impl, lower_block_cb, &state);
 168 }
 169
 170 extern "C" void
 171 nir_lower_samplers(nir_shader *shader,
 172                    const struct gl_shader_program *shader_program)
 173 {
 174    nir_foreach_overload(shader, overload) {
 175       if (overload->impl)
 176          lower_impl(overload->impl, shader_program, shader->stage);
 177    }
 178 }