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          /* XXX: We're assuming here that the indirect is the last array
  74           * thing we have.  This should be ok for now as we don't support
  75           * arrays_of_arrays yet.
  76           */
  77
  78          instr->sampler_index *= glsl_get_length(deref->type);
  79          switch (deref_array->deref_array_type) {
  80          case nir_deref_array_type_direct:
  81             instr->sampler_index += deref_array->base_offset;
  82             if (deref_array->deref.child)
  83                ralloc_asprintf_append(&name, "[%u]", deref_array->base_offset);
  84             break;
  85          case nir_deref_array_type_indirect: {
  86             instr->src = reralloc(instr, instr->src, nir_tex_src,
  87                                   instr->num_srcs + 1);
  88             memset(&instr->src[instr->num_srcs], 0, sizeof *instr->src);
  89             instr->src[instr->num_srcs].src_type = nir_tex_src_sampler_offset;
  90             instr->num_srcs++;
  91
  92             nir_instr_rewrite_src(&instr->instr,
  93                                   &instr->src[instr->num_srcs - 1].src,
  94                                   deref_array->indirect);
  95
  96             instr->sampler_array_size = glsl_get_length(deref->type);
  97
  98             nir_src empty;
  99             memset(&empty, 0, sizeof empty);
 100             nir_instr_rewrite_src(&instr->instr, &deref_array->indirect, empty);
 101
 102             if (deref_array->deref.child)
 103                ralloc_strcat(&name, "[0]");
 104             break;
 105          }
 106
 107          case nir_deref_array_type_wildcard:
 108             unreachable("Cannot copy samplers");
 109          default:
 110             unreachable("Invalid deref array type");
 111          }
 112          break;
 113       }
 114
 115       case nir_deref_type_struct: {
 116          nir_deref_struct *deref_struct = nir_deref_as_struct(deref->child);
 117          const char *field = glsl_get_struct_elem_name(deref->type,
 118                                                        deref_struct->index);
 119          ralloc_asprintf_append(&name, ".%s", field);
 120          break;
 121       }
 122
 123       default:
 124          unreachable("Invalid deref type");
 125          break;
 126       }
 127    }
 128
 129    instr->sampler_index += get_sampler_index(shader_program, stage, name);
 130
 131    instr->sampler = NULL;
 132 }
 133
 134 typedef struct {
 135    void *mem_ctx;
 136    const struct gl_shader_program *shader_program;
 137    gl_shader_stage stage;
 138 } lower_state;
 139
 140 static bool
 141 lower_block_cb(nir_block *block, void *_state)
 142 {
 143    lower_state *state = (lower_state *) _state;
 144
 145    nir_foreach_instr(block, instr) {
 146       if (instr->type == nir_instr_type_tex) {
 147          nir_tex_instr *tex_instr = nir_instr_as_tex(instr);
 148          lower_sampler(tex_instr, state->shader_program, state->stage,
 149                        state->mem_ctx);
 150       }
 151    }
 152
 153    return true;
 154 }
 155
 156 static void
 157 lower_impl(nir_function_impl *impl, const struct gl_shader_program *shader_program,
 158            gl_shader_stage stage)
 159 {
 160    lower_state state;
 161
 162    state.mem_ctx = ralloc_parent(impl);
 163    state.shader_program = shader_program;
 164    state.stage = stage;
 165
 166    nir_foreach_block(impl, lower_block_cb, &state);
 167 }
 168
 169 extern "C" void
 170 nir_lower_samplers(nir_shader *shader, const struct gl_shader_program *shader_program,
 171                    gl_shader_stage stage)
 172 {
 173    nir_foreach_overload(shader, overload) {
 174       if (overload->impl)
 175          lower_impl(overload->impl, shader_program, stage);
 176    }
 177 }