diff options
Diffstat (limited to 'lib/Analysis/MemoryDependenceAnalysis.cpp')
-rw-r--r-- | lib/Analysis/MemoryDependenceAnalysis.cpp | 30 |
1 files changed, 27 insertions, 3 deletions
diff --git a/lib/Analysis/MemoryDependenceAnalysis.cpp b/lib/Analysis/MemoryDependenceAnalysis.cpp index c4647b1f50..780d73ec23 100644 --- a/lib/Analysis/MemoryDependenceAnalysis.cpp +++ b/lib/Analysis/MemoryDependenceAnalysis.cpp @@ -690,10 +690,15 @@ static bool isPHITranslatable(Instruction *Inst) { if (isa<PHINode>(Inst)) return true; - // TODO: BITCAST, GEP. - - // ... + // We can handle bitcast of a PHI, but the PHI needs to be in the same block + // as the bitcast. + if (BitCastInst *BC = dyn_cast<BitCastInst>(Inst)) + if (PHINode *PN = dyn_cast<PHINode>(BC->getOperand(0))) + if (PN->getParent() == BC->getParent()) + return true; + // TODO: GEP, ... + // cerr << "MEMDEP: Could not PHI translate: " << *Pointer; // if (isa<BitCastInst>(PtrInst) || isa<GetElementPtrInst>(PtrInst)) // cerr << "OP:\t\t\t\t" << *PtrInst->getOperand(0); @@ -708,6 +713,25 @@ static Value *PHITranslateForPred(Instruction *Inst, BasicBlock *Pred) { if (PHINode *PN = dyn_cast<PHINode>(Inst)) return PN->getIncomingValueForBlock(Pred); + if (BitCastInst *BC = dyn_cast<BitCastInst>(Inst)) { + PHINode *BCPN = cast<PHINode>(BC->getOperand(0)); + Value *PHIIn = BCPN->getIncomingValueForBlock(Pred); + + // Constants are trivial to phi translate. + if (Constant *C = dyn_cast<Constant>(PHIIn)) + return ConstantExpr::getBitCast(C, BC->getType()); + + // Otherwise we have to see if a bitcasted version of the incoming pointer + // is available. If so, we can use it, otherwise we have to fail. + for (Value::use_iterator UI = PHIIn->use_begin(), E = PHIIn->use_end(); + UI != E; ++UI) { + if (BitCastInst *BCI = dyn_cast<BitCastInst>(*UI)) + if (BCI->getType() == BC->getType()) + return BCI; + } + return 0; + } + return 0; } |