diff options
Diffstat (limited to 'lib/Transforms/Utils/LowerInvoke.cpp')
| -rw-r--r-- | lib/Transforms/Utils/LowerInvoke.cpp | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/lib/Transforms/Utils/LowerInvoke.cpp b/lib/Transforms/Utils/LowerInvoke.cpp index 3385ba1c64..507fb86f56 100644 --- a/lib/Transforms/Utils/LowerInvoke.cpp +++ b/lib/Transforms/Utils/LowerInvoke.cpp @@ -326,7 +326,7 @@ splitLiveRangesLiveAcrossInvokes(std::vector<InvokeInst*> &Invokes) { Function *F = Invokes.back()->getParent()->getParent(); // To avoid having to handle incoming arguments specially, we lower each arg - // to a copy instruction in the entry block. This ensure that the argument + // to a copy instruction in the entry block. This ensures that the argument // value itself cannot be live across the entry block. BasicBlock::iterator AfterAllocaInsertPt = F->begin()->begin(); while (isa<AllocaInst>(AfterAllocaInsertPt) && @@ -334,10 +334,16 @@ splitLiveRangesLiveAcrossInvokes(std::vector<InvokeInst*> &Invokes) { ++AfterAllocaInsertPt; for (Function::arg_iterator AI = F->arg_begin(), E = F->arg_end(); AI != E; ++AI) { - CastInst *NC = new CastInst(AI, AI->getType(), AI->getName()+".tmp", - AfterAllocaInsertPt); + // This is always a no-op cast because we're casting AI to AI->getType() so + // src and destination types are identical. BitCast is the only possibility. + CastInst *NC = new BitCastInst( + AI, AI->getType(), AI->getName()+".tmp", AfterAllocaInsertPt); AI->replaceAllUsesWith(NC); - NC->setOperand(0, AI); + // Normally its is forbidden to replace a CastInst's operand because it + // could cause the opcode to reflect an illegal conversion. However, we're + // replacing it here with the same value it was constructed with to simply + // make NC its user. + NC->setOperand(0, AI); } // Finally, scan the code looking for instructions with bad live ranges. |