diff options
Diffstat (limited to 'llvm/lib/Transforms')
| -rw-r--r-- | llvm/lib/Transforms/Scalar/InstructionCombining.cpp | 21 |
1 files changed, 2 insertions, 19 deletions
diff --git a/llvm/lib/Transforms/Scalar/InstructionCombining.cpp b/llvm/lib/Transforms/Scalar/InstructionCombining.cpp index 5767afc4099..4ee833bf6f7 100644 --- a/llvm/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/llvm/lib/Transforms/Scalar/InstructionCombining.cpp @@ -4401,25 +4401,8 @@ static bool DeadPHICycle(PHINode *PN, std::set<PHINode*> &PotentiallyDeadPHIs) { // PHINode simplification // Instruction *InstCombiner::visitPHINode(PHINode &PN) { - if (Value *V = PN.hasConstantValue()) { - // If V is an instruction, we have to be certain that it dominates PN. - // However, because we don't have dom info, we can't do a perfect job. - if (Instruction *I = dyn_cast<Instruction>(V)) { - // We know that the instruction dominates the PHI if there are no undef - // values coming in. If the instruction is defined in the entry block, - // and is not an invoke, we know it is ok. - if (I->getParent() != &I->getParent()->getParent()->front() || - isa<InvokeInst>(I)) - for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) - if (isa<UndefValue>(PN.getIncomingValue(i))) { - V = 0; - break; - } - } - - if (V) - return ReplaceInstUsesWith(PN, V); - } + if (Value *V = PN.hasConstantValue()) + return ReplaceInstUsesWith(PN, V); // If the only user of this instruction is a cast instruction, and all of the // incoming values are constants, change this PHI to merge together the casted |
