summaryrefslogtreecommitdiff
path: root/src/glsl/nir/nir_lower_atomics.c
blob: 1aa78e18a85ed58e59addcafb6f20511f5f10453 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
/*
 * Copyright © 2014 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 *
 * Authors:
 *    Connor Abbott (cwabbott0@gmail.com)
 *
 */

#include "ir_uniform.h"
#include "nir.h"
#include "main/config.h"
#include <assert.h>

typedef struct {
   const struct gl_shader_program *shader_program;
   nir_shader   *shader;
} lower_atomic_state;

/*
 * replace atomic counter intrinsics that use a variable with intrinsics
 * that directly store the buffer index and byte offset
 */

static void
lower_instr(nir_intrinsic_instr *instr,
            lower_atomic_state *state)
{
   nir_intrinsic_op op;
   switch (instr->intrinsic) {
   case nir_intrinsic_atomic_counter_read_var:
      op = nir_intrinsic_atomic_counter_read;
      break;

   case nir_intrinsic_atomic_counter_inc_var:
      op = nir_intrinsic_atomic_counter_inc;
      break;

   case nir_intrinsic_atomic_counter_dec_var:
      op = nir_intrinsic_atomic_counter_dec;
      break;

   default:
      return;
   }

   if (instr->variables[0]->var->data.mode != nir_var_uniform &&
       instr->variables[0]->var->data.mode != nir_var_shader_storage)
      return; /* atomics passed as function arguments can't be lowered */

   void *mem_ctx = ralloc_parent(instr);
   unsigned uniform_loc = instr->variables[0]->var->data.location;

   nir_intrinsic_instr *new_instr = nir_intrinsic_instr_create(mem_ctx, op);
   new_instr->const_index[0] =
      state->shader_program->UniformStorage[uniform_loc].opaque[state->shader->stage].index;

   nir_load_const_instr *offset_const = nir_load_const_instr_create(mem_ctx, 1);
   offset_const->value.u[0] = instr->variables[0]->var->data.offset;

   nir_instr_insert_before(&instr->instr, &offset_const->instr);

   nir_ssa_def *offset_def = &offset_const->def;

   nir_deref *tail = &instr->variables[0]->deref;
   while (tail->child != NULL) {
      assert(tail->child->deref_type == nir_deref_type_array);
      nir_deref_array *deref_array = nir_deref_as_array(tail->child);
      tail = tail->child;

      unsigned child_array_elements = tail->child != NULL ?
         glsl_get_aoa_size(tail->type) : 1;

      offset_const->value.u[0] += deref_array->base_offset *
         child_array_elements * ATOMIC_COUNTER_SIZE;

      if (deref_array->deref_array_type == nir_deref_array_type_indirect) {
         nir_load_const_instr *atomic_counter_size =
               nir_load_const_instr_create(mem_ctx, 1);
         atomic_counter_size->value.u[0] = child_array_elements * ATOMIC_COUNTER_SIZE;
         nir_instr_insert_before(&instr->instr, &atomic_counter_size->instr);

         nir_alu_instr *mul = nir_alu_instr_create(mem_ctx, nir_op_imul);
         nir_ssa_dest_init(&mul->instr, &mul->dest.dest, 1, NULL);
         mul->dest.write_mask = 0x1;
         nir_src_copy(&mul->src[0].src, &deref_array->indirect, mul);
         mul->src[1].src.is_ssa = true;
         mul->src[1].src.ssa = &atomic_counter_size->def;
         nir_instr_insert_before(&instr->instr, &mul->instr);

         nir_alu_instr *add = nir_alu_instr_create(mem_ctx, nir_op_iadd);
         nir_ssa_dest_init(&add->instr, &add->dest.dest, 1, NULL);
         add->dest.write_mask = 0x1;
         add->src[0].src.is_ssa = true;
         add->src[0].src.ssa = &mul->dest.dest.ssa;
         add->src[1].src.is_ssa = true;
         add->src[1].src.ssa = offset_def;
         nir_instr_insert_before(&instr->instr, &add->instr);

         offset_def = &add->dest.dest.ssa;
      }
   }

   new_instr->src[0].is_ssa = true;
   new_instr->src[0].ssa = offset_def;

   if (instr->dest.is_ssa) {
      nir_ssa_dest_init(&new_instr->instr, &new_instr->dest,
                        instr->dest.ssa.num_components, NULL);
      nir_ssa_def_rewrite_uses(&instr->dest.ssa,
                               nir_src_for_ssa(&new_instr->dest.ssa));
   } else {
      nir_dest_copy(&new_instr->dest, &instr->dest, mem_ctx);
   }

   nir_instr_insert_before(&instr->instr, &new_instr->instr);
   nir_instr_remove(&instr->instr);
}

static bool
lower_block(nir_block *block, void *state)
{
   nir_foreach_instr_safe(block, instr) {
      if (instr->type == nir_instr_type_intrinsic)
         lower_instr(nir_instr_as_intrinsic(instr),
                     (lower_atomic_state *) state);
   }

   return true;
}

void
nir_lower_atomics(nir_shader *shader,
                  const struct gl_shader_program *shader_program)
{
   lower_atomic_state state = {
      .shader = shader,
      .shader_program = shader_program,
   };

   nir_foreach_function(shader, function) {
      if (function->impl) {
         nir_foreach_block(function->impl, lower_block, (void *) &state);
         nir_metadata_preserve(function->impl, nir_metadata_block_index |
                                               nir_metadata_dominance);
      }
   }
}