40 lines
1.5 KiB
C
40 lines
1.5 KiB
C
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//===- LoopSink.h - Loop Sink Pass ------------------------------*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This file provides the interface for the Loop Sink pass.
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_TRANSFORMS_SCALAR_LOOPSINK_H
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#define LLVM_TRANSFORMS_SCALAR_LOOPSINK_H
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#include "llvm/Analysis/LoopInfo.h"
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#include "llvm/IR/PassManager.h"
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#include "llvm/Transforms/Scalar/LoopPassManager.h"
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namespace llvm {
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/// A pass that does profile-guided sinking of instructions into loops.
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///
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/// This is a function pass as it shouldn't be composed into any kind of
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/// unified loop pass pipeline. The goal of it is to sink code into loops that
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/// is loop invariant but only required within the loop body when doing so
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/// reduces the global expected dynamic frequency with which it executes.
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/// A classic example is an extremely cold branch within a loop body.
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///
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/// We do this as a separate pass so that during normal optimization all
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/// invariant operations can be held outside the loop body to simplify
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/// fundamental analyses and transforms of the loop.
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class LoopSinkPass : public PassInfoMixin<LoopSinkPass> {
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public:
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PreservedAnalyses run(Function &F, FunctionAnalysisManager &FAM);
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};
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}
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#endif // LLVM_TRANSFORMS_SCALAR_LOOPSINK_H
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