1 // Copyright (c) 2020 André Perez Maselco
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_add_bit_instruction_synonyms.h"
16
17 #include "source/fuzz/fuzzer_util.h"
18 #include "source/fuzz/instruction_descriptor.h"
19 #include "source/fuzz/transformation_add_bit_instruction_synonym.h"
20
21 namespace spvtools {
22 namespace fuzz {
23
FuzzerPassAddBitInstructionSynonyms(opt::IRContext * ir_context,TransformationContext * transformation_context,FuzzerContext * fuzzer_context,protobufs::TransformationSequence * transformations,bool ignore_inapplicable_transformations)24 FuzzerPassAddBitInstructionSynonyms::FuzzerPassAddBitInstructionSynonyms(
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 FuzzerPassAddBitInstructionSynonyms::Apply() {
33 for (auto& function : *GetIRContext()->module()) {
34 for (auto& block : function) {
35 for (auto& instruction : block) {
36 // This fuzzer pass can add a *lot* of ids. We bail out early if we hit
37 // the recommended id limit.
38 if (GetIRContext()->module()->id_bound() >=
39 GetFuzzerContext()->GetIdBoundLimit()) {
40 return;
41 }
42
43 // Randomly decides whether the transformation will be applied.
44 if (!GetFuzzerContext()->ChoosePercentage(
45 GetFuzzerContext()->GetChanceOfAddingBitInstructionSynonym())) {
46 continue;
47 }
48
49 // Make sure fuzzer never applies a transformation to a bitwise
50 // instruction with differently signed operands, only integer operands
51 // are supported and bitwise operations are supported only.
52 if (!TransformationAddBitInstructionSynonym::IsInstructionSupported(
53 GetIRContext(), &instruction)) {
54 continue;
55 }
56
57 // Make sure all bit indexes are defined as 32-bit unsigned integers.
58 uint32_t width = GetIRContext()
59 ->get_type_mgr()
60 ->GetType(instruction.type_id())
61 ->AsInteger()
62 ->width();
63 for (uint32_t i = 0; i < width; i++) {
64 FindOrCreateIntegerConstant({i}, 32, false, false);
65 }
66
67 // Applies the add bit instruction synonym transformation.
68 ApplyTransformation(TransformationAddBitInstructionSynonym(
69 instruction.result_id(),
70 GetFuzzerContext()->GetFreshIds(
71 TransformationAddBitInstructionSynonym::GetRequiredFreshIdCount(
72 GetIRContext(), &instruction))));
73 }
74 }
75 }
76 }
77
78 } // namespace fuzz
79 } // namespace spvtools
80