src/compiler/nir/nir_gather_info.c

   1 /*
   2  * Copyright © 2015 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  21  * IN THE SOFTWARE.
  22  */
  23
  24 #include "nir.h"
  25
  26 static void
  27 gather_intrinsic_info(nir_intrinsic_instr *instr, nir_shader *shader)
  28 {
  29    switch (instr->intrinsic) {
  30    case nir_intrinsic_discard:
  31    case nir_intrinsic_discard_if:
  32       assert(shader->stage == MESA_SHADER_FRAGMENT);
  33       shader->info.fs.uses_discard = true;
  34       break;
  35
  36    case nir_intrinsic_load_front_face:
  37    case nir_intrinsic_load_vertex_id:
  38    case nir_intrinsic_load_vertex_id_zero_base:
  39    case nir_intrinsic_load_base_vertex:
  40    case nir_intrinsic_load_instance_id:
  41    case nir_intrinsic_load_sample_id:
  42    case nir_intrinsic_load_sample_pos:
  43    case nir_intrinsic_load_sample_mask_in:
  44    case nir_intrinsic_load_primitive_id:
  45    case nir_intrinsic_load_invocation_id:
  46    case nir_intrinsic_load_local_invocation_id:
  47    case nir_intrinsic_load_work_group_id:
  48    case nir_intrinsic_load_num_work_groups:
  49       shader->info.system_values_read |=
  50          (1 << nir_system_value_from_intrinsic(instr->intrinsic));
  51       break;
  52
  53    case nir_intrinsic_end_primitive:
  54    case nir_intrinsic_end_primitive_with_counter:
  55       assert(shader->stage == MESA_SHADER_GEOMETRY);
  56       shader->info.gs.uses_end_primitive = 1;
  57       break;
  58
  59    case nir_intrinsic_interp_var_at_offset:
  60       shader->info.uses_interp_var_at_offset = 1;
  61       break;
  62
  63    default:
  64       break;
  65    }
  66 }
  67
  68 static void
  69 gather_tex_info(nir_tex_instr *instr, nir_shader *shader)
  70 {
  71    if (instr->op == nir_texop_tg4)
  72       shader->info.uses_texture_gather = true;
  73 }
  74
  75 static void
  76 gather_info_block(nir_block *block, nir_shader *shader)
  77 {
  78    nir_foreach_instr(instr, block) {
  79       switch (instr->type) {
  80       case nir_instr_type_intrinsic:
  81          gather_intrinsic_info(nir_instr_as_intrinsic(instr), shader);
  82          break;
  83       case nir_instr_type_tex:
  84          gather_tex_info(nir_instr_as_tex(instr), shader);
  85          break;
  86       case nir_instr_type_call:
  87          assert(!"nir_shader_gather_info only works if functions are inlined");
  88          break;
  89       default:
  90          break;
  91       }
  92    }
  93 }
  94
  95 /**
  96  * Returns the bits in the inputs_read, outputs_written, or
  97  * system_values_read bitfield corresponding to this variable.
  98  */
  99 static inline uint64_t
 100 get_io_mask(nir_variable *var, gl_shader_stage stage)
 101 {
 102    assert(var->data.mode == nir_var_shader_in ||
 103           var->data.mode == nir_var_shader_out ||
 104           var->data.mode == nir_var_system_value);
 105    assert(var->data.location >= 0);
 106
 107    const struct glsl_type *var_type = var->type;
 108    if (stage == MESA_SHADER_GEOMETRY && var->data.mode == nir_var_shader_in) {
 109       /* Most geometry shader inputs are per-vertex arrays */
 110       if (var->data.location >= VARYING_SLOT_VAR0)
 111          assert(glsl_type_is_array(var_type));
 112
 113       if (glsl_type_is_array(var_type))
 114          var_type = glsl_get_array_element(var_type);
 115    }
 116
 117    bool is_vertex_input = (var->data.mode == nir_var_shader_in &&
 118                            stage == MESA_SHADER_VERTEX);
 119    unsigned slots = glsl_count_attribute_slots(var_type, is_vertex_input);
 120    return ((1ull << slots) - 1) << var->data.location;
 121 }
 122
 123 void
 124 nir_shader_gather_info(nir_shader *shader, nir_function_impl *entrypoint)
 125 {
 126    /* This pass does not yet support tessellation shaders */
 127    assert(shader->stage == MESA_SHADER_VERTEX ||
 128           shader->stage == MESA_SHADER_GEOMETRY ||
 129           shader->stage == MESA_SHADER_FRAGMENT ||
 130           shader->stage == MESA_SHADER_COMPUTE);
 131
 132    bool uses_sample_qualifier = false;
 133    shader->info.inputs_read = 0;
 134    foreach_list_typed(nir_variable, var, node, &shader->inputs) {
 135       shader->info.inputs_read |= get_io_mask(var, shader->stage);
 136       uses_sample_qualifier |= var->data.sample;
 137    }
 138
 139    if (shader->stage == MESA_SHADER_FRAGMENT)
 140       shader->info.fs.uses_sample_qualifier = uses_sample_qualifier;
 141
 142    /* TODO: Some day we may need to add stream support to NIR */
 143    shader->info.outputs_written = 0;
 144    foreach_list_typed(nir_variable, var, node, &shader->outputs)
 145       shader->info.outputs_written |= get_io_mask(var, shader->stage);
 146
 147    shader->info.system_values_read = 0;
 148    foreach_list_typed(nir_variable, var, node, &shader->system_values)
 149       shader->info.system_values_read |= get_io_mask(var, shader->stage);
 150
 151    shader->info.num_textures = 0;
 152    shader->info.num_images = 0;
 153    nir_foreach_variable(var, &shader->uniforms) {
 154       const struct glsl_type *type = var->type;
 155       unsigned count = 1;
 156       if (glsl_type_is_array(type)) {
 157          count = glsl_get_length(type);
 158          type = glsl_get_array_element(type);
 159       }
 160
 161       if (glsl_type_is_image(type)) {
 162          shader->info.num_images += count;
 163       } else if (glsl_type_is_sampler(type)) {
 164          shader->info.num_textures += count;
 165       }
 166    }
 167
 168    nir_foreach_block(block, entrypoint) {
 169       gather_info_block(block, shader);
 170    }
 171 }