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annotate lib/Analysis/CFG.cpp @ 0:95c75e76d11b LLVM3.4

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LLVM 3.4
author Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
date Thu, 12 Dec 2013 13:56:28 +0900
parents
children 54457678186b
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1 //===-- CFG.cpp - BasicBlock analysis --------------------------------------==//
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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 family of functions performs analyses on basic blocks, and instructions
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11 // contained within basic blocks.
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12 //
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13 //===----------------------------------------------------------------------===//
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14
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15 #include "llvm/Analysis/CFG.h"
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16
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17 #include "llvm/ADT/SmallSet.h"
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18 #include "llvm/Analysis/Dominators.h"
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19 #include "llvm/Analysis/LoopInfo.h"
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20
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21 using namespace llvm;
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22
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23 /// FindFunctionBackedges - Analyze the specified function to find all of the
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24 /// loop backedges in the function and return them. This is a relatively cheap
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25 /// (compared to computing dominators and loop info) analysis.
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26 ///
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27 /// The output is added to Result, as pairs of <from,to> edge info.
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28 void llvm::FindFunctionBackedges(const Function &F,
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29 SmallVectorImpl<std::pair<const BasicBlock*,const BasicBlock*> > &Result) {
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30 const BasicBlock *BB = &F.getEntryBlock();
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31 if (succ_begin(BB) == succ_end(BB))
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32 return;
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33
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34 SmallPtrSet<const BasicBlock*, 8> Visited;
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35 SmallVector<std::pair<const BasicBlock*, succ_const_iterator>, 8> VisitStack;
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36 SmallPtrSet<const BasicBlock*, 8> InStack;
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37
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38 Visited.insert(BB);
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39 VisitStack.push_back(std::make_pair(BB, succ_begin(BB)));
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40 InStack.insert(BB);
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41 do {
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42 std::pair<const BasicBlock*, succ_const_iterator> &Top = VisitStack.back();
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43 const BasicBlock *ParentBB = Top.first;
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44 succ_const_iterator &I = Top.second;
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45
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46 bool FoundNew = false;
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47 while (I != succ_end(ParentBB)) {
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48 BB = *I++;
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49 if (Visited.insert(BB)) {
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50 FoundNew = true;
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51 break;
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52 }
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53 // Successor is in VisitStack, it's a back edge.
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54 if (InStack.count(BB))
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55 Result.push_back(std::make_pair(ParentBB, BB));
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56 }
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57
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58 if (FoundNew) {
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59 // Go down one level if there is a unvisited successor.
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60 InStack.insert(BB);
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61 VisitStack.push_back(std::make_pair(BB, succ_begin(BB)));
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62 } else {
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63 // Go up one level.
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64 InStack.erase(VisitStack.pop_back_val().first);
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65 }
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66 } while (!VisitStack.empty());
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67 }
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68
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69 /// GetSuccessorNumber - Search for the specified successor of basic block BB
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70 /// and return its position in the terminator instruction's list of
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71 /// successors. It is an error to call this with a block that is not a
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72 /// successor.
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73 unsigned llvm::GetSuccessorNumber(BasicBlock *BB, BasicBlock *Succ) {
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74 TerminatorInst *Term = BB->getTerminator();
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75 #ifndef NDEBUG
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76 unsigned e = Term->getNumSuccessors();
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77 #endif
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78 for (unsigned i = 0; ; ++i) {
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79 assert(i != e && "Didn't find edge?");
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80 if (Term->getSuccessor(i) == Succ)
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81 return i;
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82 }
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83 }
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84
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85 /// isCriticalEdge - Return true if the specified edge is a critical edge.
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86 /// Critical edges are edges from a block with multiple successors to a block
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87 /// with multiple predecessors.
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88 bool llvm::isCriticalEdge(const TerminatorInst *TI, unsigned SuccNum,
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89 bool AllowIdenticalEdges) {
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90 assert(SuccNum < TI->getNumSuccessors() && "Illegal edge specification!");
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91 if (TI->getNumSuccessors() == 1) return false;
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92
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93 const BasicBlock *Dest = TI->getSuccessor(SuccNum);
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94 const_pred_iterator I = pred_begin(Dest), E = pred_end(Dest);
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95
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96 // If there is more than one predecessor, this is a critical edge...
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97 assert(I != E && "No preds, but we have an edge to the block?");
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98 const BasicBlock *FirstPred = *I;
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99 ++I; // Skip one edge due to the incoming arc from TI.
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100 if (!AllowIdenticalEdges)
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101 return I != E;
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102
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103 // If AllowIdenticalEdges is true, then we allow this edge to be considered
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104 // non-critical iff all preds come from TI's block.
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105 while (I != E) {
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106 const BasicBlock *P = *I;
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107 if (P != FirstPred)
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108 return true;
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109 // Note: leave this as is until no one ever compiles with either gcc 4.0.1
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110 // or Xcode 2. This seems to work around the pred_iterator assert in PR 2207
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111 E = pred_end(P);
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112 ++I;
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113 }
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114 return false;
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115 }
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116
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117 // LoopInfo contains a mapping from basic block to the innermost loop. Find
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118 // the outermost loop in the loop nest that contains BB.
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119 static const Loop *getOutermostLoop(const LoopInfo *LI, const BasicBlock *BB) {
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120 const Loop *L = LI->getLoopFor(BB);
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121 if (L) {
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122 while (const Loop *Parent = L->getParentLoop())
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123 L = Parent;
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124 }
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125 return L;
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126 }
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127
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128 // True if there is a loop which contains both BB1 and BB2.
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129 static bool loopContainsBoth(const LoopInfo *LI,
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Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
130 const BasicBlock *BB1, const BasicBlock *BB2) {
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
131 const Loop *L1 = getOutermostLoop(LI, BB1);
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
132 const Loop *L2 = getOutermostLoop(LI, BB2);
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
133 return L1 != NULL && L1 == L2;
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
134 }
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
135
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
136 static bool isPotentiallyReachableInner(SmallVectorImpl<BasicBlock *> &Worklist,
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
137 BasicBlock *StopBB,
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
138 const DominatorTree *DT,
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
139 const LoopInfo *LI) {
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
140 // When the stop block is unreachable, it's dominated from everywhere,
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
141 // regardless of whether there's a path between the two blocks.
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
142 if (DT && !DT->isReachableFromEntry(StopBB))
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
143 DT = 0;
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
144
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
145 // Limit the number of blocks we visit. The goal is to avoid run-away compile
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
146 // times on large CFGs without hampering sensible code. Arbitrarily chosen.
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
147 unsigned Limit = 32;
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
148 SmallSet<const BasicBlock*, 64> Visited;
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
149 do {
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
150 BasicBlock *BB = Worklist.pop_back_val();
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
151 if (!Visited.insert(BB))
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
152 continue;
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
153 if (BB == StopBB)
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
154 return true;
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
155 if (DT && DT->dominates(BB, StopBB))
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
156 return true;
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
157 if (LI && loopContainsBoth(LI, BB, StopBB))
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
158 return true;
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
159
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
160 if (!--Limit) {
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
161 // We haven't been able to prove it one way or the other. Conservatively
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
162 // answer true -- that there is potentially a path.
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
163 return true;
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
164 }
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
165
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
166 if (const Loop *Outer = LI ? getOutermostLoop(LI, BB) : 0) {
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
167 // All blocks in a single loop are reachable from all other blocks. From
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
168 // any of these blocks, we can skip directly to the exits of the loop,
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
169 // ignoring any other blocks inside the loop body.
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
170 Outer->getExitBlocks(Worklist);
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
171 } else {
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
172 for (succ_iterator I = succ_begin(BB), E = succ_end(BB); I != E; ++I)
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
173 Worklist.push_back(*I);
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
174 }
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
175 } while (!Worklist.empty());
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
176
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
177 // We have exhausted all possible paths and are certain that 'To' can not be
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
178 // reached from 'From'.
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
179 return false;
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
180 }
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
181
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
182 bool llvm::isPotentiallyReachable(const BasicBlock *A, const BasicBlock *B,
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
183 const DominatorTree *DT, const LoopInfo *LI) {
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
184 assert(A->getParent() == B->getParent() &&
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
185 "This analysis is function-local!");
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 SmallVector<BasicBlock*, 32> Worklist;
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
188 Worklist.push_back(const_cast<BasicBlock*>(A));
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 return isPotentiallyReachableInner(Worklist, const_cast<BasicBlock*>(B),
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
191 DT, LI);
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
192 }
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
193
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
194 bool llvm::isPotentiallyReachable(const Instruction *A, const Instruction *B,
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
195 const DominatorTree *DT, const LoopInfo *LI) {
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
196 assert(A->getParent()->getParent() == B->getParent()->getParent() &&
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
197 "This analysis is function-local!");
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
198
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
199 SmallVector<BasicBlock*, 32> Worklist;
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 (A->getParent() == B->getParent()) {
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
202 // The same block case is special because it's the only time we're looking
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
203 // within a single block to see which instruction comes first. Once we
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
204 // start looking at multiple blocks, the first instruction of the block is
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
205 // reachable, so we only need to determine reachability between whole
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
206 // blocks.
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
207 BasicBlock *BB = const_cast<BasicBlock *>(A->getParent());
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
208
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
209 // If the block is in a loop then we can reach any instruction in the block
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
210 // from any other instruction in the block by going around a backedge.
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
211 if (LI && LI->getLoopFor(BB) != 0)
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
212 return true;
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
213
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
214 // Linear scan, start at 'A', see whether we hit 'B' or the end first.
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
215 for (BasicBlock::const_iterator I = A, E = BB->end(); I != E; ++I) {
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
216 if (&*I == B)
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
217 return true;
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
218 }
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
219
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
220 // Can't be in a loop if it's the entry block -- the entry block may not
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
221 // have predecessors.
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
222 if (BB == &BB->getParent()->getEntryBlock())
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
223 return false;
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 // Otherwise, continue doing the normal per-BB CFG walk.
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
226 for (succ_iterator I = succ_begin(BB), E = succ_end(BB); I != E; ++I)
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
227 Worklist.push_back(*I);
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
228
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
229 if (Worklist.empty()) {
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
230 // We've proven that there's no path!
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
231 return false;
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
232 }
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
233 } else {
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
234 Worklist.push_back(const_cast<BasicBlock*>(A->getParent()));
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
235 }
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
236
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
237 if (A->getParent() == &A->getParent()->getParent()->getEntryBlock())
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
238 return true;
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
239 if (B->getParent() == &A->getParent()->getParent()->getEntryBlock())
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
240 return false;
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 return isPotentiallyReachableInner(Worklist,
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
243 const_cast<BasicBlock*>(B->getParent()),
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
244 DT, LI);
95c75e76d11b LLVM 3.4
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
245 }