mirror of
https://github.com/RPCS3/llvm.git
synced 2026-01-31 01:25:19 +01:00
39c1e3d2d7
This implements PGO-driven loop peeling. The basic idea is that when the average dynamic trip-count of a loop is known, based on PGO, to be low, we can expect a performance win by peeling off the first several iterations of that loop. Unlike unrolling based on a known trip count, or a trip count multiple, this doesn't save us the conditional check and branch on each iteration. However, it does allow us to simplify the straight-line code we get (constant-folding, etc.). This is important given that we know that we will usually only hit this code, and not the actual loop. This is currently disabled by default. Differential Revision: https://reviews.llvm.org/D25963 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@288274 91177308-0d34-0410-b5e6-96231b3b80d8
59 lines
2.1 KiB
C++
59 lines
2.1 KiB
C++
//===- llvm/Transforms/Utils/UnrollLoop.h - Unrolling utilities -*- C++ -*-===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file defines some loop unrolling utilities. It does not define any
|
|
// actual pass or policy, but provides a single function to perform loop
|
|
// unrolling.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef LLVM_TRANSFORMS_UTILS_UNROLLLOOP_H
|
|
#define LLVM_TRANSFORMS_UTILS_UNROLLLOOP_H
|
|
|
|
// Needed because we can't forward-declare the nested struct
|
|
// TargetTransformInfo::UnrollingPreferences
|
|
#include "llvm/Analysis/TargetTransformInfo.h"
|
|
|
|
namespace llvm {
|
|
|
|
class StringRef;
|
|
class AssumptionCache;
|
|
class DominatorTree;
|
|
class Loop;
|
|
class LoopInfo;
|
|
class LPPassManager;
|
|
class MDNode;
|
|
class Pass;
|
|
class OptimizationRemarkEmitter;
|
|
class ScalarEvolution;
|
|
|
|
bool UnrollLoop(Loop *L, unsigned Count, unsigned TripCount, bool Force,
|
|
bool AllowRuntime, bool AllowExpensiveTripCount,
|
|
bool PreserveCondBr, bool PreserveOnlyFirst,
|
|
unsigned TripMultiple, unsigned PeelCount, LoopInfo *LI,
|
|
ScalarEvolution *SE, DominatorTree *DT, AssumptionCache *AC,
|
|
OptimizationRemarkEmitter *ORE, bool PreserveLCSSA);
|
|
|
|
bool UnrollRuntimeLoopRemainder(Loop *L, unsigned Count,
|
|
bool AllowExpensiveTripCount,
|
|
bool UseEpilogRemainder, LoopInfo *LI,
|
|
ScalarEvolution *SE, DominatorTree *DT,
|
|
bool PreserveLCSSA);
|
|
|
|
void computePeelCount(Loop *L, unsigned LoopSize,
|
|
TargetTransformInfo::UnrollingPreferences &UP);
|
|
|
|
bool peelLoop(Loop *L, unsigned PeelCount, LoopInfo *LI, ScalarEvolution *SE,
|
|
DominatorTree *DT, bool PreserveLCSSA);
|
|
|
|
MDNode *GetUnrollMetadata(MDNode *LoopID, StringRef Name);
|
|
}
|
|
|
|
#endif
|