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annotate lib/Analysis/ScalarEvolutionNormalization.cpp @ 116:a609e5c42ecc

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author mir3636
date Mon, 08 Aug 2016 19:47:00 +0900
parents afa8332a0e37
children 1172e4bd9c6f
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1 //===- ScalarEvolutionNormalization.cpp - See below -------------*- C++ -*-===//
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2 //
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3 // The LLVM Compiler Infrastructure
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4 //
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5 // This file is distributed under the University of Illinois Open Source
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6 // License. See LICENSE.TXT for details.
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7 //
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8 //===----------------------------------------------------------------------===//
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9 //
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10 // This file implements utilities for working with "normalized" expressions.
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11 // See the comments at the top of ScalarEvolutionNormalization.h for details.
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12 //
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13 //===----------------------------------------------------------------------===//
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14
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15 #include "llvm/IR/Dominators.h"
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16 #include "llvm/Analysis/LoopInfo.h"
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17 #include "llvm/Analysis/ScalarEvolutionExpressions.h"
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18 #include "llvm/Analysis/ScalarEvolutionNormalization.h"
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19 using namespace llvm;
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20
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21 /// IVUseShouldUsePostIncValue - We have discovered a "User" of an IV expression
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22 /// and now we need to decide whether the user should use the preinc or post-inc
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23 /// value. If this user should use the post-inc version of the IV, return true.
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24 ///
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25 /// Choosing wrong here can break dominance properties (if we choose to use the
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26 /// post-inc value when we cannot) or it can end up adding extra live-ranges to
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27 /// the loop, resulting in reg-reg copies (if we use the pre-inc value when we
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28 /// should use the post-inc value).
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29 static bool IVUseShouldUsePostIncValue(Instruction *User, Value *Operand,
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30 const Loop *L, DominatorTree *DT) {
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31 // If the user is in the loop, use the preinc value.
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32 if (L->contains(User)) return false;
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33
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34 BasicBlock *LatchBlock = L->getLoopLatch();
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35 if (!LatchBlock)
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36 return false;
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37
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38 // Ok, the user is outside of the loop. If it is dominated by the latch
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39 // block, use the post-inc value.
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40 if (DT->dominates(LatchBlock, User->getParent()))
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41 return true;
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42
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43 // There is one case we have to be careful of: PHI nodes. These little guys
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44 // can live in blocks that are not dominated by the latch block, but (since
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45 // their uses occur in the predecessor block, not the block the PHI lives in)
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46 // should still use the post-inc value. Check for this case now.
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47 PHINode *PN = dyn_cast<PHINode>(User);
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48 if (!PN || !Operand) return false; // not a phi, not dominated by latch block.
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49
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50 // Look at all of the uses of Operand by the PHI node. If any use corresponds
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51 // to a block that is not dominated by the latch block, give up and use the
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52 // preincremented value.
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53 for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
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54 if (PN->getIncomingValue(i) == Operand &&
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55 !DT->dominates(LatchBlock, PN->getIncomingBlock(i)))
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56 return false;
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57
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58 // Okay, all uses of Operand by PN are in predecessor blocks that really are
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59 // dominated by the latch block. Use the post-incremented value.
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60 return true;
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61 }
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62
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63 namespace {
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64
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65 /// Hold the state used during post-inc expression transformation, including a
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66 /// map of transformed expressions.
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67 class PostIncTransform {
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68 TransformKind Kind;
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69 PostIncLoopSet &Loops;
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70 ScalarEvolution &SE;
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71 DominatorTree &DT;
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72
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73 DenseMap<const SCEV*, const SCEV*> Transformed;
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74
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75 public:
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76 PostIncTransform(TransformKind kind, PostIncLoopSet &loops,
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77 ScalarEvolution &se, DominatorTree &dt):
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78 Kind(kind), Loops(loops), SE(se), DT(dt) {}
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79
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80 const SCEV *TransformSubExpr(const SCEV *S, Instruction *User,
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81 Value *OperandValToReplace);
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82
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83 protected:
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84 const SCEV *TransformImpl(const SCEV *S, Instruction *User,
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85 Value *OperandValToReplace);
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86 };
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87
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88 } // namespace
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89
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90 /// Implement post-inc transformation for all valid expression types.
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91 const SCEV *PostIncTransform::
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92 TransformImpl(const SCEV *S, Instruction *User, Value *OperandValToReplace) {
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93
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94 if (const SCEVCastExpr *X = dyn_cast<SCEVCastExpr>(S)) {
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95 const SCEV *O = X->getOperand();
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96 const SCEV *N = TransformSubExpr(O, User, OperandValToReplace);
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97 if (O != N)
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98 switch (S->getSCEVType()) {
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99 case scZeroExtend: return SE.getZeroExtendExpr(N, S->getType());
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100 case scSignExtend: return SE.getSignExtendExpr(N, S->getType());
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101 case scTruncate: return SE.getTruncateExpr(N, S->getType());
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102 default: llvm_unreachable("Unexpected SCEVCastExpr kind!");
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103 }
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104 return S;
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105 }
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106
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107 if (const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(S)) {
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108 // An addrec. This is the interesting part.
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109 SmallVector<const SCEV *, 8> Operands;
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110 const Loop *L = AR->getLoop();
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111 // The addrec conceptually uses its operands at loop entry.
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112 Instruction *LUser = &L->getHeader()->front();
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113 // Transform each operand.
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114 for (SCEVNAryExpr::op_iterator I = AR->op_begin(), E = AR->op_end();
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115 I != E; ++I) {
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116 Operands.push_back(TransformSubExpr(*I, LUser, nullptr));
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117 }
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118 // Conservatively use AnyWrap until/unless we need FlagNW.
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119 const SCEV *Result = SE.getAddRecExpr(Operands, L, SCEV::FlagAnyWrap);
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120 switch (Kind) {
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121 case NormalizeAutodetect:
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122 // Normalize this SCEV by subtracting the expression for the final step.
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123 // We only allow affine AddRecs to be normalized, otherwise we would not
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124 // be able to correctly denormalize.
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125 // e.g. {1,+,3,+,2} == {-2,+,1,+,2} + {3,+,2}
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126 // Normalized form: {-2,+,1,+,2}
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
127 // Denormalized form: {1,+,3,+,2}
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
128 //
77
54457678186b LLVM 3.6
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents: 0
diff changeset
129 // However, denormalization would use a different step expression than
0
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
130 // normalization (see getPostIncExpr), generating the wrong final
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
131 // expression: {-2,+,1,+,2} + {1,+,2} => {-1,+,3,+,2}
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
132 if (AR->isAffine() &&
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
133 IVUseShouldUsePostIncValue(User, OperandValToReplace, L, &DT)) {
77
54457678186b LLVM 3.6
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents: 0
diff changeset
134 const SCEV *TransformedStep =
54457678186b LLVM 3.6
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents: 0
diff changeset
135 TransformSubExpr(AR->getStepRecurrence(SE),
54457678186b LLVM 3.6
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents: 0
diff changeset
136 User, OperandValToReplace);
54457678186b LLVM 3.6
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents: 0
diff changeset
137 Result = SE.getMinusSCEV(Result, TransformedStep);
0
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
138 Loops.insert(L);
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
139 }
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
140 #if 0
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
141 // This assert is conceptually correct, but ScalarEvolution currently
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
142 // sometimes fails to canonicalize two equal SCEVs to exactly the same
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
143 // form. It's possibly a pessimization when this happens, but it isn't a
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
144 // correctness problem, so disable this assert for now.
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
145 assert(S == TransformSubExpr(Result, User, OperandValToReplace) &&
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
146 "SCEV normalization is not invertible!");
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
147 #endif
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
148 break;
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
149 case Normalize:
77
54457678186b LLVM 3.6
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents: 0
diff changeset
150 // We want to normalize step expression, because otherwise we might not be
54457678186b LLVM 3.6
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents: 0
diff changeset
151 // able to denormalize to the original expression.
54457678186b LLVM 3.6
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents: 0
diff changeset
152 //
54457678186b LLVM 3.6
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents: 0
diff changeset
153 // Here is an example what will happen if we don't normalize step:
54457678186b LLVM 3.6
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents: 0
diff changeset
154 // ORIGINAL ISE:
54457678186b LLVM 3.6
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents: 0
diff changeset
155 // {(100 /u {1,+,1}<%bb16>),+,(100 /u {1,+,1}<%bb16>)}<%bb25>
54457678186b LLVM 3.6
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents: 0
diff changeset
156 // NORMALIZED ISE:
54457678186b LLVM 3.6
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents: 0
diff changeset
157 // {((-1 * (100 /u {1,+,1}<%bb16>)) + (100 /u {0,+,1}<%bb16>)),+,
54457678186b LLVM 3.6
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents: 0
diff changeset
158 // (100 /u {0,+,1}<%bb16>)}<%bb25>
54457678186b LLVM 3.6
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents: 0
diff changeset
159 // DENORMALIZED BACK ISE:
54457678186b LLVM 3.6
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents: 0
diff changeset
160 // {((2 * (100 /u {1,+,1}<%bb16>)) + (-1 * (100 /u {2,+,1}<%bb16>))),+,
54457678186b LLVM 3.6
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents: 0
diff changeset
161 // (100 /u {1,+,1}<%bb16>)}<%bb25>
54457678186b LLVM 3.6
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents: 0
diff changeset
162 // Note that the initial value changes after normalization +
54457678186b LLVM 3.6
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents: 0
diff changeset
163 // denormalization, which isn't correct.
0
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
164 if (Loops.count(L)) {
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
165 const SCEV *TransformedStep =
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
166 TransformSubExpr(AR->getStepRecurrence(SE),
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
167 User, OperandValToReplace);
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
168 Result = SE.getMinusSCEV(Result, TransformedStep);
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
169 }
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
170 #if 0
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
171 // See the comment on the assert above.
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
172 assert(S == TransformSubExpr(Result, User, OperandValToReplace) &&
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
173 "SCEV normalization is not invertible!");
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
174 #endif
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
175 break;
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
176 case Denormalize:
77
54457678186b LLVM 3.6
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents: 0
diff changeset
177 // Here we want to normalize step expressions for the same reasons, as
54457678186b LLVM 3.6
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents: 0
diff changeset
178 // stated above.
54457678186b LLVM 3.6
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents: 0
diff changeset
179 if (Loops.count(L)) {
54457678186b LLVM 3.6
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents: 0
diff changeset
180 const SCEV *TransformedStep =
54457678186b LLVM 3.6
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents: 0
diff changeset
181 TransformSubExpr(AR->getStepRecurrence(SE),
54457678186b LLVM 3.6
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents: 0
diff changeset
182 User, OperandValToReplace);
54457678186b LLVM 3.6
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents: 0
diff changeset
183 Result = SE.getAddExpr(Result, TransformedStep);
54457678186b LLVM 3.6
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents: 0
diff changeset
184 }
0
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
185 break;
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
186 }
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
187 return Result;
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
188 }
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
189
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
190 if (const SCEVNAryExpr *X = dyn_cast<SCEVNAryExpr>(S)) {
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
191 SmallVector<const SCEV *, 8> Operands;
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
192 bool Changed = false;
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
193 // Transform each operand.
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
194 for (SCEVNAryExpr::op_iterator I = X->op_begin(), E = X->op_end();
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
195 I != E; ++I) {
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
196 const SCEV *O = *I;
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
197 const SCEV *N = TransformSubExpr(O, User, OperandValToReplace);
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
198 Changed |= N != O;
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
199 Operands.push_back(N);
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
200 }
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
201 // If any operand actually changed, return a transformed result.
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
202 if (Changed)
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
203 switch (S->getSCEVType()) {
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
204 case scAddExpr: return SE.getAddExpr(Operands);
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
205 case scMulExpr: return SE.getMulExpr(Operands);
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
206 case scSMaxExpr: return SE.getSMaxExpr(Operands);
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
207 case scUMaxExpr: return SE.getUMaxExpr(Operands);
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
208 default: llvm_unreachable("Unexpected SCEVNAryExpr kind!");
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
209 }
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
210 return S;
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
211 }
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
212
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
213 if (const SCEVUDivExpr *X = dyn_cast<SCEVUDivExpr>(S)) {
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
214 const SCEV *LO = X->getLHS();
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
215 const SCEV *RO = X->getRHS();
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
216 const SCEV *LN = TransformSubExpr(LO, User, OperandValToReplace);
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
217 const SCEV *RN = TransformSubExpr(RO, User, OperandValToReplace);
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
218 if (LO != LN || RO != RN)
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
219 return SE.getUDivExpr(LN, RN);
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
220 return S;
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
221 }
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
222
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
223 llvm_unreachable("Unexpected SCEV kind!");
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
224 }
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
225
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
226 /// Manage recursive transformation across an expression DAG. Revisiting
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
227 /// expressions would lead to exponential recursion.
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
228 const SCEV *PostIncTransform::
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
229 TransformSubExpr(const SCEV *S, Instruction *User, Value *OperandValToReplace) {
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
230
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
231 if (isa<SCEVConstant>(S) || isa<SCEVUnknown>(S))
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
232 return S;
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
233
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
234 const SCEV *Result = Transformed.lookup(S);
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
235 if (Result)
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
236 return Result;
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
237
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
238 Result = TransformImpl(S, User, OperandValToReplace);
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
239 Transformed[S] = Result;
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
240 return Result;
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
241 }
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
242
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
243 /// Top level driver for transforming an expression DAG into its requested
77
54457678186b LLVM 3.6
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents: 0
diff changeset
244 /// post-inc form (either "Normalized" or "Denormalized").
0
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
245 const SCEV *llvm::TransformForPostIncUse(TransformKind Kind,
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
246 const SCEV *S,
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
247 Instruction *User,
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
248 Value *OperandValToReplace,
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
249 PostIncLoopSet &Loops,
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
250 ScalarEvolution &SE,
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
251 DominatorTree &DT) {
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
252 PostIncTransform Transform(Kind, Loops, SE, DT);
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
253 return Transform.TransformSubExpr(S, User, OperandValToReplace);
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
254 }