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)24 FuzzerPassAddBitInstructionSynonyms::FuzzerPassAddBitInstructionSynonyms(
25     opt::IRContext* ir_context, TransformationContext* transformation_context,
26     FuzzerContext* fuzzer_context,
27     protobufs::TransformationSequence* transformations)
28     : FuzzerPass(ir_context, transformation_context, fuzzer_context,
29                  transformations) {}
30 
31 FuzzerPassAddBitInstructionSynonyms::~FuzzerPassAddBitInstructionSynonyms() =
32     default;
33 
Apply()34 void FuzzerPassAddBitInstructionSynonyms::Apply() {
35   for (auto& function : *GetIRContext()->module()) {
36     for (auto& block : function) {
37       for (auto& instruction : block) {
38         // This fuzzer pass can add a *lot* of ids.  We bail out early if we hit
39         // the recommended id limit.
40         if (GetIRContext()->module()->id_bound() >=
41             GetFuzzerContext()->GetIdBoundLimit()) {
42           return;
43         }
44 
45         // Randomly decides whether the transformation will be applied.
46         if (!GetFuzzerContext()->ChoosePercentage(
47                 GetFuzzerContext()->GetChanceOfAddingBitInstructionSynonym())) {
48           continue;
49         }
50 
51         // TODO(https://github.com/KhronosGroup/SPIRV-Tools/issues/3557):
52         //  Right now we only support certain operations. When this issue is
53         //  addressed the following conditional can use the function
54         //  |spvOpcodeIsBit|.
55         if (instruction.opcode() != SpvOpBitwiseOr &&
56             instruction.opcode() != SpvOpBitwiseXor &&
57             instruction.opcode() != SpvOpBitwiseAnd &&
58             instruction.opcode() != SpvOpNot) {
59           continue;
60         }
61 
62         // Right now, only integer operands are supported.
63         if (GetIRContext()
64                 ->get_type_mgr()
65                 ->GetType(instruction.type_id())
66                 ->AsVector()) {
67           continue;
68         }
69 
70         // Make sure all bit indexes are defined as 32-bit unsigned integers.
71         uint32_t width = GetIRContext()
72                              ->get_type_mgr()
73                              ->GetType(instruction.type_id())
74                              ->AsInteger()
75                              ->width();
76         for (uint32_t i = 0; i < width; i++) {
77           FindOrCreateIntegerConstant({i}, 32, false, false);
78         }
79 
80         // Applies the add bit instruction synonym transformation.
81         ApplyTransformation(TransformationAddBitInstructionSynonym(
82             instruction.result_id(),
83             GetFuzzerContext()->GetFreshIds(
84                 TransformationAddBitInstructionSynonym::GetRequiredFreshIdCount(
85                     GetIRContext(), &instruction))));
86       }
87     }
88   }
89 }
90 
91 }  // namespace fuzz
92 }  // namespace spvtools
93