mirror of
https://github.com/KhronosGroup/SPIRV-Tools
synced 2024-10-19 03:20:14 +00:00
044ecc0b2c
This introduces a new fuzzer pass to add instructions to the module that define equations, and support in the fact manager for recording equation facts and deducing synonym facts from equation facts. Initially the only equations that are supported involve OpIAdd, OpISub, OpSNegate and OpLogicalNot, but there is scope for adding support for equations over various other operators.
236 lines
9.4 KiB
C++
236 lines
9.4 KiB
C++
// Copyright (c) 2020 Google LLC
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
#include "source/fuzz/fuzzer_pass_add_equation_instructions.h"
|
|
|
|
#include <vector>
|
|
|
|
#include "source/fuzz/fuzzer_util.h"
|
|
#include "source/fuzz/transformation_equation_instruction.h"
|
|
|
|
namespace spvtools {
|
|
namespace fuzz {
|
|
|
|
FuzzerPassAddEquationInstructions::FuzzerPassAddEquationInstructions(
|
|
opt::IRContext* ir_context, FactManager* fact_manager,
|
|
FuzzerContext* fuzzer_context,
|
|
protobufs::TransformationSequence* transformations)
|
|
: FuzzerPass(ir_context, fact_manager, fuzzer_context, transformations) {}
|
|
|
|
FuzzerPassAddEquationInstructions::~FuzzerPassAddEquationInstructions() =
|
|
default;
|
|
|
|
void FuzzerPassAddEquationInstructions::Apply() {
|
|
MaybeAddTransformationBeforeEachInstruction(
|
|
[this](opt::Function* function, opt::BasicBlock* block,
|
|
opt::BasicBlock::iterator inst_it,
|
|
const protobufs::InstructionDescriptor& instruction_descriptor) {
|
|
if (!GetFuzzerContext()->ChoosePercentage(
|
|
GetFuzzerContext()->GetChanceOfAddingEquationInstruction())) {
|
|
return;
|
|
}
|
|
|
|
// Check that it is OK to add an equation instruction before the given
|
|
// instruction in principle - e.g. check that this does not lead to
|
|
// inserting before an OpVariable or OpPhi instruction. We use OpIAdd
|
|
// as an example opcode for this check, to be representative of *some*
|
|
// opcode that defines an equation, even though we may choose a
|
|
// different opcode below.
|
|
if (!fuzzerutil::CanInsertOpcodeBeforeInstruction(SpvOpIAdd, inst_it)) {
|
|
return;
|
|
}
|
|
|
|
// Get all available instructions with result ids and types that are not
|
|
// OpUndef.
|
|
std::vector<opt::Instruction*> available_instructions =
|
|
FindAvailableInstructions(
|
|
function, block, inst_it,
|
|
[](opt::IRContext*, opt::Instruction* instruction) -> bool {
|
|
return instruction->result_id() && instruction->type_id() &&
|
|
instruction->opcode() != SpvOpUndef;
|
|
});
|
|
|
|
// Try the opcodes for which we know how to make ids at random until
|
|
// something works.
|
|
std::vector<SpvOp> candidate_opcodes = {SpvOpIAdd, SpvOpISub,
|
|
SpvOpLogicalNot, SpvOpSNegate};
|
|
do {
|
|
auto opcode =
|
|
GetFuzzerContext()->RemoveAtRandomIndex(&candidate_opcodes);
|
|
switch (opcode) {
|
|
case SpvOpIAdd:
|
|
case SpvOpISub: {
|
|
// Instructions of integer (scalar or vector) result type are
|
|
// suitable for these opcodes.
|
|
auto integer_instructions =
|
|
GetIntegerInstructions(available_instructions);
|
|
if (!integer_instructions.empty()) {
|
|
// There is at least one such instruction, so pick one at random
|
|
// for the LHS of an equation.
|
|
auto lhs = integer_instructions.at(
|
|
GetFuzzerContext()->RandomIndex(integer_instructions));
|
|
|
|
// For the RHS, we can use any instruction with an integer
|
|
// scalar/vector result type of the same number of components
|
|
// and the same bit-width for the underlying integer type.
|
|
|
|
// Work out the element count and bit-width.
|
|
auto lhs_type =
|
|
GetIRContext()->get_type_mgr()->GetType(lhs->type_id());
|
|
uint32_t lhs_element_count;
|
|
uint32_t lhs_bit_width;
|
|
if (lhs_type->AsVector()) {
|
|
lhs_element_count = lhs_type->AsVector()->element_count();
|
|
lhs_bit_width = lhs_type->AsVector()
|
|
->element_type()
|
|
->AsInteger()
|
|
->width();
|
|
} else {
|
|
lhs_element_count = 1;
|
|
lhs_bit_width = lhs_type->AsInteger()->width();
|
|
}
|
|
|
|
// Get all the instructions that match on element count and
|
|
// bit-width.
|
|
auto candidate_rhs_instructions = RestrictToElementBitWidth(
|
|
RestrictToVectorWidth(integer_instructions,
|
|
lhs_element_count),
|
|
lhs_bit_width);
|
|
|
|
// Choose a RHS instruction at random; there is guaranteed to
|
|
// be at least one choice as the LHS will be available.
|
|
auto rhs = candidate_rhs_instructions.at(
|
|
GetFuzzerContext()->RandomIndex(
|
|
candidate_rhs_instructions));
|
|
|
|
// Add the equation instruction.
|
|
ApplyTransformation(TransformationEquationInstruction(
|
|
GetFuzzerContext()->GetFreshId(), opcode,
|
|
{lhs->result_id(), rhs->result_id()},
|
|
instruction_descriptor));
|
|
return;
|
|
}
|
|
break;
|
|
}
|
|
case SpvOpLogicalNot: {
|
|
// Choose any available instruction of boolean scalar/vector
|
|
// result type and equate its negation with a fresh id.
|
|
auto boolean_instructions =
|
|
GetBooleanInstructions(available_instructions);
|
|
if (!boolean_instructions.empty()) {
|
|
ApplyTransformation(TransformationEquationInstruction(
|
|
GetFuzzerContext()->GetFreshId(), opcode,
|
|
{boolean_instructions
|
|
.at(GetFuzzerContext()->RandomIndex(
|
|
boolean_instructions))
|
|
->result_id()},
|
|
instruction_descriptor));
|
|
return;
|
|
}
|
|
break;
|
|
}
|
|
case SpvOpSNegate: {
|
|
// Similar to OpLogicalNot, but for signed integer negation.
|
|
auto integer_instructions =
|
|
GetIntegerInstructions(available_instructions);
|
|
if (!integer_instructions.empty()) {
|
|
ApplyTransformation(TransformationEquationInstruction(
|
|
GetFuzzerContext()->GetFreshId(), opcode,
|
|
{integer_instructions
|
|
.at(GetFuzzerContext()->RandomIndex(
|
|
integer_instructions))
|
|
->result_id()},
|
|
instruction_descriptor));
|
|
return;
|
|
}
|
|
break;
|
|
}
|
|
default:
|
|
assert(false && "Unexpected opcode.");
|
|
break;
|
|
}
|
|
} while (!candidate_opcodes.empty());
|
|
// Reaching here means that we did not manage to apply any
|
|
// transformation at this point of the module.
|
|
});
|
|
}
|
|
|
|
std::vector<opt::Instruction*>
|
|
FuzzerPassAddEquationInstructions::GetIntegerInstructions(
|
|
const std::vector<opt::Instruction*>& instructions) const {
|
|
std::vector<opt::Instruction*> result;
|
|
for (auto& inst : instructions) {
|
|
auto type = GetIRContext()->get_type_mgr()->GetType(inst->type_id());
|
|
if (type->AsInteger() ||
|
|
(type->AsVector() && type->AsVector()->element_type()->AsInteger())) {
|
|
result.push_back(inst);
|
|
}
|
|
}
|
|
return result;
|
|
}
|
|
|
|
std::vector<opt::Instruction*>
|
|
FuzzerPassAddEquationInstructions::GetBooleanInstructions(
|
|
const std::vector<opt::Instruction*>& instructions) const {
|
|
std::vector<opt::Instruction*> result;
|
|
for (auto& inst : instructions) {
|
|
auto type = GetIRContext()->get_type_mgr()->GetType(inst->type_id());
|
|
if (type->AsBool() ||
|
|
(type->AsVector() && type->AsVector()->element_type()->AsBool())) {
|
|
result.push_back(inst);
|
|
}
|
|
}
|
|
return result;
|
|
}
|
|
|
|
std::vector<opt::Instruction*>
|
|
FuzzerPassAddEquationInstructions::RestrictToVectorWidth(
|
|
const std::vector<opt::Instruction*>& instructions,
|
|
uint32_t vector_width) const {
|
|
std::vector<opt::Instruction*> result;
|
|
for (auto& inst : instructions) {
|
|
auto type = GetIRContext()->get_type_mgr()->GetType(inst->type_id());
|
|
if ((vector_width == 1 && !type->AsVector()) ||
|
|
(vector_width > 1 &&
|
|
type->AsVector()->element_count() == vector_width)) {
|
|
result.push_back(inst);
|
|
}
|
|
}
|
|
return result;
|
|
}
|
|
|
|
std::vector<opt::Instruction*>
|
|
FuzzerPassAddEquationInstructions::RestrictToElementBitWidth(
|
|
const std::vector<opt::Instruction*>& instructions,
|
|
uint32_t bit_width) const {
|
|
std::vector<opt::Instruction*> result;
|
|
for (auto& inst : instructions) {
|
|
const opt::analysis::Type* type =
|
|
GetIRContext()->get_type_mgr()->GetType(inst->type_id());
|
|
if (type->AsVector()) {
|
|
type = type->AsVector()->element_type();
|
|
}
|
|
assert(type->AsInteger() &&
|
|
"Precondition: all input instructions must "
|
|
"have integer scalar or vector type.");
|
|
if (type->AsInteger()->width() == bit_width) {
|
|
result.push_back(inst);
|
|
}
|
|
}
|
|
return result;
|
|
}
|
|
|
|
} // namespace fuzz
|
|
} // namespace spvtools
|