chromium/v8/src/compiler/turboshaft/loop-unrolling-reducer.h

// Copyright 2023 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef V8_COMPILER_TURBOSHAFT_LOOP_UNROLLING_REDUCER_H_
#define V8_COMPILER_TURBOSHAFT_LOOP_UNROLLING_REDUCER_H_

#include <optional>

#include "src/base/logging.h"
#include "src/compiler/globals.h"
#include "src/compiler/turboshaft/assembler.h"
#include "src/compiler/turboshaft/copying-phase.h"
#include "src/compiler/turboshaft/index.h"
#include "src/compiler/turboshaft/loop-finder.h"
#include "src/compiler/turboshaft/machine-optimization-reducer.h"
#include "src/compiler/turboshaft/operations.h"
#include "src/compiler/turboshaft/phase.h"

namespace v8::internal::compiler::turboshaft {

#include "src/compiler/turboshaft/define-assembler-macros.inc"

// OVERVIEW:
//
// LoopUnrollingReducer fully unrolls small inner loops with a small
// statically-computable number of iterations, partially unrolls other small
// inner loops, and remove loops that we detect as always having 0 iterations.

class IterationCount { … };
std::ostream& operator<<(std::ostream& os, const IterationCount& count);

class V8_EXPORT_PRIVATE StaticCanonicalForLoopMatcher { … };
std::ostream& operator<<(std::ostream& os,
                         const StaticCanonicalForLoopMatcher::CmpOp& cmp);
std::ostream& operator<<(std::ostream& os,
                         const StaticCanonicalForLoopMatcher::BinOp& binop);

class V8_EXPORT_PRIVATE LoopUnrollingAnalyzer { … };

template <class Next>
class LoopPeelingReducer;

template <class Next>
class LoopStackCheckElisionReducer : public Next { … };

template <class Next>
class LoopUnrollingReducer : public Next { … };

template <class Next>
void LoopUnrollingReducer<Next>::PartiallyUnrollLoop(const Block* header) { … }

template <class Next>
void LoopUnrollingReducer<Next>::FixLoopPhis(const Block* input_graph_loop,
                                             Block* output_graph_loop,
                                             const Block* backedge_block) { … }

template <class Next>
void LoopUnrollingReducer<Next>::RemoveLoop(const Block* header) { … }

template <class Next>
void LoopUnrollingReducer<Next>::FullyUnrollLoop(const Block* header) { … }

#include "src/compiler/turboshaft/undef-assembler-macros.inc"

}  // namespace v8::internal::compiler::turboshaft

#endif  // V8_COMPILER_TURBOSHAFT_LOOP_UNROLLING_REDUCER_H_