SPIRV-Tools/source/fuzz/transformation_replace_id_with_synonym.h
Alastair Donaldson 041f0a0249
spirv-fuzz: simplify transformation for replacing an id with a synonym (#3020)
Prior to this change, TransformationReplaceIdWithSynonym was designed
to be able to replace an id with some synonymous data descriptor,
possibly necessitating extracting from a composite into a fresh id in
order to get at the synonymous data.  This change simplifies things so
that TransformationReplaceIdWithSynonym just allows one id to be
replaced by another id.  It is the responsibility of the associated
fuzzer pass - FuzzerPassApplyIdSynonyms - to perform the extraction
operations, using e.g. TransformationCompositeExtract.
2019-11-07 16:19:06 +00:00

81 lines
3.5 KiB
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// Copyright (c) 2019 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.
#ifndef SOURCE_FUZZ_TRANSFORMATION_REPLACE_ID_WITH_SYNONYM_H_
#define SOURCE_FUZZ_TRANSFORMATION_REPLACE_ID_WITH_SYNONYM_H_
#include "source/fuzz/fact_manager.h"
#include "source/fuzz/protobufs/spirvfuzz_protobufs.h"
#include "source/fuzz/transformation.h"
#include "source/opt/ir_context.h"
namespace spvtools {
namespace fuzz {
class TransformationReplaceIdWithSynonym : public Transformation {
public:
explicit TransformationReplaceIdWithSynonym(
const protobufs::TransformationReplaceIdWithSynonym& message);
TransformationReplaceIdWithSynonym(
protobufs::IdUseDescriptor id_use_descriptor, uint32_t synonymous_id);
// - The fact manager must know that the id identified by
// |message_.id_use_descriptor| is synonomous with
// |message_.synonymous_id|.
// - Replacing the id in |message_.id_use_descriptor| by
// |message_.synonymous_id| must respect SPIR-V's rules about uses being
// dominated by their definitions.
// - The id must not be an index into an access chain whose base object has
// struct type, as such indices must be constants.
// - The id must not be a pointer argument to a function call (because the
// synonym might not be a memory object declaration).
// - |fresh_id_for_temporary| must be 0.
bool IsApplicable(opt::IRContext* context,
const FactManager& fact_manager) const override;
// Replaces the use identified by |message_.id_use_descriptor| with the
// synonymous id identified by |message_.synonymous_id|.
void Apply(opt::IRContext* context, FactManager* fact_manager) const override;
protobufs::Transformation ToMessage() const override;
// Checks whether the |id| is available (according to dominance rules) at the
// use point defined by input operand |use_input_operand_index| of
// |use_instruction|.
static bool IdsIsAvailableAtUse(opt::IRContext* context,
opt::Instruction* use_instruction,
uint32_t use_input_operand_index,
uint32_t id);
// Checks whether various conditions hold related to the acceptability of
// replacing the id use at |use_in_operand_index| of |use_instruction| with
// a synonym. In particular, this checks that:
// - the id use is not an index into a struct field in an OpAccessChain - such
// indices must be constants, so it is dangerous to replace them.
// - the id use is not a pointer function call argument, on which there are
// restrictions that make replacement problematic.
static bool UseCanBeReplacedWithSynonym(opt::IRContext* context,
opt::Instruction* use_instruction,
uint32_t use_in_operand_index);
private:
protobufs::TransformationReplaceIdWithSynonym message_;
};
} // namespace fuzz
} // namespace spvtools
#endif // SOURCE_FUZZ_TRANSFORMATION_REPLACE_ID_WITH_SYNONYM_H_