Coverage Report

Created: 2019-07-24 05:18

/Users/buildslave/jenkins/workspace/clang-stage2-coverage-R/llvm/include/llvm/Transforms/Scalar/Reassociate.h
Line
Count
Source
1
//===- Reassociate.h - Reassociate binary expressions -----------*- C++ -*-===//
2
//
3
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4
// See https://llvm.org/LICENSE.txt for license information.
5
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6
//
7
//===----------------------------------------------------------------------===//
8
//
9
// This pass reassociates commutative expressions in an order that is designed
10
// to promote better constant propagation, GCSE, LICM, PRE, etc.
11
//
12
// For example: 4 + (x + 5) -> x + (4 + 5)
13
//
14
// In the implementation of this algorithm, constants are assigned rank = 0,
15
// function arguments are rank = 1, and other values are assigned ranks
16
// corresponding to the reverse post order traversal of current function
17
// (starting at 2), which effectively gives values in deep loops higher rank
18
// than values not in loops.
19
//
20
//===----------------------------------------------------------------------===//
21
22
#ifndef LLVM_TRANSFORMS_SCALAR_REASSOCIATE_H
23
#define LLVM_TRANSFORMS_SCALAR_REASSOCIATE_H
24
25
#include "llvm/ADT/DenseMap.h"
26
#include "llvm/ADT/PostOrderIterator.h"
27
#include "llvm/ADT/SetVector.h"
28
#include "llvm/IR/IRBuilder.h"
29
#include "llvm/IR/PassManager.h"
30
#include "llvm/IR/ValueHandle.h"
31
#include <deque>
32
33
namespace llvm {
34
35
class APInt;
36
class BasicBlock;
37
class BinaryOperator;
38
class Function;
39
class Instruction;
40
class Value;
41
42
/// A private "module" namespace for types and utilities used by Reassociate.
43
/// These are implementation details and should not be used by clients.
44
namespace reassociate {
45
46
struct ValueEntry {
47
  unsigned Rank;
48
  Value *Op;
49
50
2.07M
  ValueEntry(unsigned R, Value *O) : Rank(R), Op(O) {}
51
};
52
53
942k
inline bool operator<(const ValueEntry &LHS, const ValueEntry &RHS) {
54
942k
  return LHS.Rank > RHS.Rank; // Sort so that highest rank goes to start.
55
942k
}
56
57
/// Utility class representing a base and exponent pair which form one
58
/// factor of some product.
59
struct Factor {
60
  Value *Base;
61
  unsigned Power;
62
63
22
  Factor(Value *Base, unsigned Power) : Base(Base), Power(Power) {}
64
};
65
66
class XorOpnd;
67
68
} // end namespace reassociate
69
70
/// Reassociate commutative expressions.
71
class ReassociatePass : public PassInfoMixin<ReassociatePass> {
72
public:
73
  using OrderedSet =
74
      SetVector<AssertingVH<Instruction>, std::deque<AssertingVH<Instruction>>>;
75
76
protected:
77
  DenseMap<BasicBlock *, unsigned> RankMap;
78
  DenseMap<AssertingVH<Value>, unsigned> ValueRankMap;
79
  OrderedSet RedoInsts;
80
81
  // Arbitrary, but prevents quadratic behavior.
82
  static const unsigned GlobalReassociateLimit = 10;
83
  static const unsigned NumBinaryOps =
84
      Instruction::BinaryOpsEnd - Instruction::BinaryOpsBegin;
85
86
  struct PairMapValue {
87
    WeakVH Value1;
88
    WeakVH Value2;
89
    unsigned Score;
90
284k
    bool isValid() const { return Value1 && 
Value2284k
; }
91
  };
92
  DenseMap<std::pair<Value *, Value *>, PairMapValue> PairMap[NumBinaryOps];
93
94
  bool MadeChange;
95
96
public:
97
  PreservedAnalyses run(Function &F, FunctionAnalysisManager &);
98
99
private:
100
  void BuildRankMap(Function &F, ReversePostOrderTraversal<Function *> &RPOT);
101
  unsigned getRank(Value *V);
102
  void canonicalizeOperands(Instruction *I);
103
  void ReassociateExpression(BinaryOperator *I);
104
  void RewriteExprTree(BinaryOperator *I,
105
                       SmallVectorImpl<reassociate::ValueEntry> &Ops);
106
  Value *OptimizeExpression(BinaryOperator *I,
107
                            SmallVectorImpl<reassociate::ValueEntry> &Ops);
108
  Value *OptimizeAdd(Instruction *I,
109
                     SmallVectorImpl<reassociate::ValueEntry> &Ops);
110
  Value *OptimizeXor(Instruction *I,
111
                     SmallVectorImpl<reassociate::ValueEntry> &Ops);
112
  bool CombineXorOpnd(Instruction *I, reassociate::XorOpnd *Opnd1,
113
                      APInt &ConstOpnd, Value *&Res);
114
  bool CombineXorOpnd(Instruction *I, reassociate::XorOpnd *Opnd1,
115
                      reassociate::XorOpnd *Opnd2, APInt &ConstOpnd,
116
                      Value *&Res);
117
  Value *buildMinimalMultiplyDAG(IRBuilder<> &Builder,
118
                                 SmallVectorImpl<reassociate::Factor> &Factors);
119
  Value *OptimizeMul(BinaryOperator *I,
120
                     SmallVectorImpl<reassociate::ValueEntry> &Ops);
121
  Value *RemoveFactorFromExpression(Value *V, Value *Factor);
122
  void EraseInst(Instruction *I);
123
  void RecursivelyEraseDeadInsts(Instruction *I, OrderedSet &Insts);
124
  void OptimizeInst(Instruction *I);
125
  Instruction *canonicalizeNegConstExpr(Instruction *I);
126
  void BuildPairMap(ReversePostOrderTraversal<Function *> &RPOT);
127
};
128
129
} // end namespace llvm
130
131
#endif // LLVM_TRANSFORMS_SCALAR_REASSOCIATE_H