aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/libs/llvm12/include/llvm/Transforms/Utils/UnrollLoop.h
blob: f279ae996620990a7d41722ff2cd634e5aa4ff7f (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
#pragma once

#ifdef __GNUC__
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-parameter"
#endif

//===- llvm/Transforms/Utils/UnrollLoop.h - Unrolling utilities -*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// 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

#include "llvm/ADT/DenseMap.h"
#include "llvm/Analysis/TargetTransformInfo.h"

namespace llvm {

class AssumptionCache;
class BasicBlock;
class BlockFrequencyInfo;
class DependenceInfo;
class DominatorTree;
class Loop;
class LoopInfo;
class MDNode;
class ProfileSummaryInfo;
class OptimizationRemarkEmitter;
class ScalarEvolution;
class StringRef;
class Value;

using NewLoopsMap = SmallDenseMap<const Loop *, Loop *, 4>;

/// @{
/// Metadata attribute names
const char *const LLVMLoopUnrollFollowupAll = "llvm.loop.unroll.followup_all";
const char *const LLVMLoopUnrollFollowupUnrolled =
    "llvm.loop.unroll.followup_unrolled";
const char *const LLVMLoopUnrollFollowupRemainder =
    "llvm.loop.unroll.followup_remainder";
/// @}

const Loop* addClonedBlockToLoopInfo(BasicBlock *OriginalBB,
                                     BasicBlock *ClonedBB, LoopInfo *LI,
                                     NewLoopsMap &NewLoops);

/// Represents the result of a \c UnrollLoop invocation.
enum class LoopUnrollResult {
  /// The loop was not modified.
  Unmodified,

  /// The loop was partially unrolled -- we still have a loop, but with a
  /// smaller trip count.  We may also have emitted epilogue loop if the loop
  /// had a non-constant trip count.
  PartiallyUnrolled,

  /// The loop was fully unrolled into straight-line code.  We no longer have
  /// any back-edges.
  FullyUnrolled
};

struct UnrollLoopOptions {
  unsigned Count;
  unsigned TripCount;
  bool Force;
  bool AllowRuntime;
  bool AllowExpensiveTripCount;
  bool PreserveCondBr;
  bool PreserveOnlyFirst;
  unsigned TripMultiple;
  unsigned PeelCount;
  bool UnrollRemainder;
  bool ForgetAllSCEV;
};

LoopUnrollResult UnrollLoop(Loop *L, UnrollLoopOptions ULO, LoopInfo *LI,
                            ScalarEvolution *SE, DominatorTree *DT,
                            AssumptionCache *AC,
                            const llvm::TargetTransformInfo *TTI,
                            OptimizationRemarkEmitter *ORE, bool PreserveLCSSA,
                            Loop **RemainderLoop = nullptr);

bool UnrollRuntimeLoopRemainder(
    Loop *L, unsigned Count, bool AllowExpensiveTripCount,
    bool UseEpilogRemainder, bool UnrollRemainder, bool ForgetAllSCEV,
    LoopInfo *LI, ScalarEvolution *SE, DominatorTree *DT, AssumptionCache *AC,
    const TargetTransformInfo *TTI, bool PreserveLCSSA,
    Loop **ResultLoop = nullptr);

LoopUnrollResult UnrollAndJamLoop(Loop *L, unsigned Count, unsigned TripCount,
                                  unsigned TripMultiple, bool UnrollRemainder,
                                  LoopInfo *LI, ScalarEvolution *SE,
                                  DominatorTree *DT, AssumptionCache *AC,
                                  const TargetTransformInfo *TTI,
                                  OptimizationRemarkEmitter *ORE,
                                  Loop **EpilogueLoop = nullptr);

bool isSafeToUnrollAndJam(Loop *L, ScalarEvolution &SE, DominatorTree &DT,
                          DependenceInfo &DI, LoopInfo &LI);

bool computeUnrollCount(Loop *L, const TargetTransformInfo &TTI,
                        DominatorTree &DT, LoopInfo *LI, ScalarEvolution &SE,
                        const SmallPtrSetImpl<const Value *> &EphValues,
                        OptimizationRemarkEmitter *ORE, unsigned &TripCount,
                        unsigned MaxTripCount, bool MaxOrZero,
                        unsigned &TripMultiple, unsigned LoopSize,
                        TargetTransformInfo::UnrollingPreferences &UP,
                        TargetTransformInfo::PeelingPreferences &PP,
                        bool &UseUpperBound);

void simplifyLoopAfterUnroll(Loop *L, bool SimplifyIVs, LoopInfo *LI,
                             ScalarEvolution *SE, DominatorTree *DT,
                             AssumptionCache *AC,
                             const TargetTransformInfo *TTI);

MDNode *GetUnrollMetadata(MDNode *LoopID, StringRef Name);

TargetTransformInfo::UnrollingPreferences gatherUnrollingPreferences(
    Loop *L, ScalarEvolution &SE, const TargetTransformInfo &TTI,
    BlockFrequencyInfo *BFI, ProfileSummaryInfo *PSI, int OptLevel,
    Optional<unsigned> UserThreshold, Optional<unsigned> UserCount,
    Optional<bool> UserAllowPartial, Optional<bool> UserRuntime,
    Optional<bool> UserUpperBound, Optional<unsigned> UserFullUnrollMaxCount);

unsigned ApproximateLoopSize(const Loop *L, unsigned &NumCalls,
                             bool &NotDuplicatable, bool &Convergent,
                             const TargetTransformInfo &TTI,
                             const SmallPtrSetImpl<const Value *> &EphValues,
                             unsigned BEInsns);

} // end namespace llvm

#endif // LLVM_TRANSFORMS_UTILS_UNROLLLOOP_H

#ifdef __GNUC__
#pragma GCC diagnostic pop
#endif