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, const char *name,
  40                   const struct gl_program *prog)
  41 {
  42    GLuint shader = _mesa_program_enum_to_shader_stage(prog->Target);
  43
  44    unsigned location;
  45    if (!shader_program->UniformHash->get(location, name)) {
  46       linker_error(shader_program,
  47                    "failed to find sampler named %s.\n", name);
  48       return 0;
  49    }
  50
  51    if (!shader_program->UniformStorage[location].sampler[shader].active) {
  52       assert(0 && "cannot return a sampler");
  53       linker_error(shader_program,
  54                    "cannot return a sampler named %s, because it is not "
  55                    "used in this shader stage. This is a driver bug.\n",
  56                    name);
  57       return 0;
  58    }
  59
  60    return shader_program->UniformStorage[location].sampler[shader].index;
  61 }
  62
  63 static void
  64 lower_sampler(nir_tex_instr *instr, struct gl_shader_program *shader_program,
  65               const struct gl_program *prog, void *mem_ctx)
  66 {
  67    if (instr->sampler == NULL)
  68       return;
  69
  70    /* Get the name and the offset */
  71    instr->sampler_index = 0;
  72    bool has_indirect = false;
  73    char *name = ralloc_strdup(mem_ctx, instr->sampler->var->name);
  74
  75    for (nir_deref *deref = &instr->sampler->deref;
  76         deref->child; deref = deref->child) {
  77       switch (deref->child->deref_type) {
  78       case nir_deref_type_array: {
  79          nir_deref_array *deref_array = nir_deref_as_array(deref->child);
  80
  81          /* XXX: We're assuming here that the indirect is the last array
  82           * thing we have.  This should be ok for now as we don't support
  83           * arrays_of_arrays yet.
  84           */
  85          assert(!has_indirect);
  86
  87          instr->sampler_index *= glsl_get_length(deref->type);
  88          switch (deref_array->deref_array_type) {
  89          case nir_deref_array_type_direct:
  90             instr->sampler_index += deref_array->base_offset;
  91             if (deref_array->deref.child)
  92                ralloc_asprintf_append(&name, "[%u]", deref_array->base_offset);
  93             break;
  94          case nir_deref_array_type_indirect: {
  95             assert(!has_indirect);
  96
  97             instr->src = reralloc(mem_ctx, instr->src, nir_tex_src,
  98                                   instr->num_srcs + 1);
  99             memset(&instr->src[instr->num_srcs], 0, sizeof *instr->src);
 100             instr->src[instr->num_srcs].src_type = nir_tex_src_sampler_offset;
 101             instr->num_srcs++;
 102
 103             nir_instr_rewrite_src(&instr->instr,
 104                                   &instr->src[instr->num_srcs - 1].src,
 105                                   nir_src_copy(deref_array->indirect, mem_ctx));
 106
 107             instr->sampler_array_size = glsl_get_length(deref->type);
 108
 109             nir_src empty;
 110             memset(&empty, 0, sizeof empty);
 111             nir_instr_rewrite_src(&instr->instr, &deref_array->indirect, empty);
 112
 113             if (deref_array->deref.child)
 114                ralloc_strcat(&name, "[0]");
 115             break;
 116          }
 117
 118          case nir_deref_array_type_wildcard:
 119             unreachable("Cannot copy samplers");
 120          default:
 121             unreachable("Invalid deref array type");
 122          }
 123          break;
 124       }
 125
 126       case nir_deref_type_struct: {
 127          nir_deref_struct *deref_struct = nir_deref_as_struct(deref->child);
 128          const char *field = glsl_get_struct_elem_name(deref->type,
 129                                                        deref_struct->index);
 130          ralloc_asprintf_append(&name, ".%s", field);
 131          break;
 132       }
 133
 134       default:
 135          unreachable("Invalid deref type");
 136          break;
 137       }
 138    }
 139
 140    instr->sampler_index += get_sampler_index(shader_program, name, prog);
 141
 142    instr->sampler = NULL;
 143 }
 144
 145 typedef struct {
 146    void *mem_ctx;
 147    struct gl_shader_program *shader_program;
 148    struct gl_program *prog;
 149 } lower_state;
 150
 151 static bool
 152 lower_block_cb(nir_block *block, void *_state)
 153 {
 154    lower_state *state = (lower_state *) _state;
 155
 156    nir_foreach_instr(block, instr) {
 157       if (instr->type == nir_instr_type_tex) {
 158          nir_tex_instr *tex_instr = nir_instr_as_tex(instr);
 159          lower_sampler(tex_instr, state->shader_program, state->prog,
 160                        state->mem_ctx);
 161       }
 162    }
 163
 164    return true;
 165 }
 166
 167 static void
 168 lower_impl(nir_function_impl *impl, struct gl_shader_program *shader_program,
 169            struct gl_program *prog)
 170 {
 171    lower_state state;
 172
 173    state.mem_ctx = ralloc_parent(impl);
 174    state.shader_program = shader_program;
 175    state.prog = prog;
 176
 177    nir_foreach_block(impl, lower_block_cb, &state);
 178 }
 179
 180 extern "C" void
 181 nir_lower_samplers(nir_shader *shader, struct gl_shader_program *shader_program,
 182                    struct gl_program *prog)
 183 {
 184    nir_foreach_overload(shader, overload) {
 185       if (overload->impl)
 186          lower_impl(overload->impl, shader_program, prog);
 187    }
 188 }