SPIRV-Tools/source/fuzz/transformation_add_loop_preheader.h
Stefano Milizia 2aaa8653da
spirv-fuzz: Transformation to add loop preheader (#3599)
This PR introduces TransformationAddLoopPreheader, which, given
a loop header and enough fresh ids, adds a loop preheader, updating
all the references so that this new block is the only out-of-loop
predecessor of the header, which branches unconditionally to the
header.

See the discussion in #3095.
2020-07-30 20:18:19 +01:00

58 lines
2.2 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.
#ifndef SOURCE_FUZZ_TRANSFORMATION_ADD_LOOP_PREHEADER_H
#define SOURCE_FUZZ_TRANSFORMATION_ADD_LOOP_PREHEADER_H
#include "source/fuzz/transformation.h"
namespace spvtools {
namespace fuzz {
class TransformationAddLoopPreheader : public Transformation {
public:
explicit TransformationAddLoopPreheader(
const protobufs::TransformationAddLoopPreheader& message);
TransformationAddLoopPreheader(uint32_t loop_header_block, uint32_t fresh_id,
std::vector<uint32_t> phi_id);
// - |message_.loop_header_block| must be the id of a loop header block in
// the given module.
// - |message_.fresh_id| must be an available id.
// - |message_.phi_ids| must be a list of available ids.
// It can be empty if the loop header only has one predecessor outside of
// the loop. Otherwise, it must contain at least as many ids as OpPhi
// instructions in the loop header block.
bool IsApplicable(
opt::IRContext* ir_context,
const TransformationContext& transformation_context) const override;
// Adds a preheader block as the unique out-of-loop predecessor of the given
// loop header block. All of the existing out-of-loop predecessors of the
// header are changed so that they branch to the preheader instead.
void Apply(opt::IRContext* ir_context,
TransformationContext* transformation_context) const override;
protobufs::Transformation ToMessage() const override;
private:
protobufs::TransformationAddLoopPreheader message_;
};
} // namespace fuzz
} // namespace spvtools
#endif // SOURCE_FUZZ_TRANSFORMATION_ADD_LOOP_PREHEADER_H