1/*
2 * Copyright © 2020 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
26static bool
27nir_opt_combine_memory_barriers_impl(
28   nir_function_impl *impl, nir_combine_memory_barrier_cb combine_cb, void *data)
29{
30   bool progress = false;
31
32   nir_foreach_block(block, impl) {
33      nir_intrinsic_instr *prev = NULL;
34
35      nir_foreach_instr_safe(instr, block) {
36         if (instr->type != nir_instr_type_intrinsic) {
37            prev = NULL;
38            continue;
39         }
40
41         nir_intrinsic_instr *current = nir_instr_as_intrinsic(instr);
42         if (current->intrinsic != nir_intrinsic_scoped_barrier ||
43             nir_intrinsic_execution_scope(current) != NIR_SCOPE_NONE) {
44            prev = NULL;
45            continue;
46         }
47
48         if (prev && combine_cb(prev, current, data)) {
49            nir_instr_remove(&current->instr);
50            progress = true;
51         } else {
52            prev = current;
53         }
54      }
55   }
56
57   if (progress) {
58      nir_metadata_preserve(impl, nir_metadata_block_index |
59                                  nir_metadata_dominance |
60                                  nir_metadata_live_ssa_defs);
61   } else {
62      nir_metadata_preserve(impl, nir_metadata_all);
63   }
64
65   return progress;
66}
67
68/* Combine adjacent scoped memory barriers. */
69bool
70nir_opt_combine_memory_barriers(
71   nir_shader *shader, nir_combine_memory_barrier_cb combine_cb, void *data)
72{
73   assert(combine_cb);
74
75   bool progress = false;
76
77   nir_foreach_function(function, shader) {
78      if (function->impl &&
79          nir_opt_combine_memory_barriers_impl(function->impl, combine_cb, data)) {
80         progress = true;
81      }
82   }
83
84   return progress;
85}
86