1 // Copyright (c) 2019 Google LLC
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14
15 #include "source/fuzz/fuzzer_pass_merge_blocks.h"
16
17 #include <vector>
18
19 #include "source/fuzz/transformation_merge_blocks.h"
20
21 namespace spvtools {
22 namespace fuzz {
23
FuzzerPassMergeBlocks(opt::IRContext * ir_context,TransformationContext * transformation_context,FuzzerContext * fuzzer_context,protobufs::TransformationSequence * transformations,bool ignore_inapplicable_transformations)24 FuzzerPassMergeBlocks::FuzzerPassMergeBlocks(
25 opt::IRContext* ir_context, TransformationContext* transformation_context,
26 FuzzerContext* fuzzer_context,
27 protobufs::TransformationSequence* transformations,
28 bool ignore_inapplicable_transformations)
29 : FuzzerPass(ir_context, transformation_context, fuzzer_context,
30 transformations, ignore_inapplicable_transformations) {}
31
Apply()32 void FuzzerPassMergeBlocks::Apply() {
33 // First we populate a sequence of transformations that we might consider
34 // applying.
35 std::vector<TransformationMergeBlocks> potential_transformations;
36 // We do this by considering every block of every function.
37 for (auto& function : *GetIRContext()->module()) {
38 for (auto& block : function) {
39 // We probabilistically decide to ignore some blocks.
40 if (!GetFuzzerContext()->ChoosePercentage(
41 GetFuzzerContext()->GetChanceOfMergingBlocks())) {
42 continue;
43 }
44 // For other blocks, we add a transformation to merge the block into its
45 // predecessor if that transformation would be applicable.
46 TransformationMergeBlocks transformation(block.id());
47 if (transformation.IsApplicable(GetIRContext(),
48 *GetTransformationContext())) {
49 potential_transformations.push_back(transformation);
50 }
51 }
52 }
53
54 while (!potential_transformations.empty()) {
55 auto transformation =
56 GetFuzzerContext()->RemoveAtRandomIndex(&potential_transformations);
57 MaybeApplyTransformation(transformation);
58 }
59 }
60
61 } // namespace fuzz
62 } // namespace spvtools
63