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 
26 static bool
nir_opt_combine_memory_barriers_impl(nir_function_impl * impl,nir_combine_memory_barrier_cb combine_cb,void * data)27 nir_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. */
69 bool
nir_opt_combine_memory_barriers(nir_shader * shader,nir_combine_memory_barrier_cb combine_cb,void * data)70 nir_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