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Diffstat (limited to 'lib/Transforms/Scalar/JumpThreading.cpp')
-rw-r--r--lib/Transforms/Scalar/JumpThreading.cpp23
1 files changed, 13 insertions, 10 deletions
diff --git a/lib/Transforms/Scalar/JumpThreading.cpp b/lib/Transforms/Scalar/JumpThreading.cpp
index 47bebf90d3..e7a87e098d 100644
--- a/lib/Transforms/Scalar/JumpThreading.cpp
+++ b/lib/Transforms/Scalar/JumpThreading.cpp
@@ -377,6 +377,7 @@ ComputeValueKnownInPredecessors(Value *V, BasicBlock *BB,PredValueInfo &Result){
// If comparing a live-in value against a constant, see if we know the
// live-in value on any predecessors.
if (LVI && isa<Constant>(Cmp->getOperand(1)) &&
+ Cmp->getType()->isInteger() && // Not vector compare.
(!isa<Instruction>(Cmp->getOperand(0)) ||
cast<Instruction>(Cmp->getOperand(0))->getParent() != BB)) {
Constant *RHSCst = cast<Constant>(Cmp->getOperand(1));
@@ -384,14 +385,14 @@ ComputeValueKnownInPredecessors(Value *V, BasicBlock *BB,PredValueInfo &Result){
for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI) {
// If the value is known by LazyValueInfo to be a constant in a
// predecessor, use that information to try to thread this block.
- Constant *PredCst = LVI->getConstantOnEdge(Cmp->getOperand(0), *PI, BB);
- if (PredCst == 0)
+ LazyValueInfo::Tristate
+ Res = LVI->getPredicateOnEdge(Cmp->getPredicate(), Cmp->getOperand(0),
+ RHSCst, *PI, BB);
+ if (Res == LazyValueInfo::Unknown)
continue;
-
- // Constant fold the compare.
- Value *Res = SimplifyCmpInst(Cmp->getPredicate(), PredCst, RHSCst, TD);
- if (isa<ConstantInt>(Res) || isa<UndefValue>(Res))
- Result.push_back(std::make_pair(dyn_cast<ConstantInt>(Res), *PI));
+
+ Constant *ResC = ConstantInt::get(Cmp->getType(), Res);
+ Result.push_back(std::make_pair(cast<ConstantInt>(ResC), *PI));
}
return !Result.empty();
@@ -498,7 +499,8 @@ bool JumpThreading::ProcessBlock(BasicBlock *BB) {
// br COND, BBX, BBY
// BBX:
// br COND, BBZ, BBW
- if (!Condition->hasOneUse() && // Multiple uses.
+ if (!LVI &&
+ !Condition->hasOneUse() && // Multiple uses.
(CondInst == 0 || CondInst->getParent() != BB)) { // Non-local definition.
pred_iterator PI = pred_begin(BB), E = pred_end(BB);
if (isa<BranchInst>(BB->getTerminator())) {
@@ -532,8 +534,9 @@ bool JumpThreading::ProcessBlock(BasicBlock *BB) {
return ProcessJumpOnPHI(PN);
if (CmpInst *CondCmp = dyn_cast<CmpInst>(CondInst)) {
- if (!isa<PHINode>(CondCmp->getOperand(0)) ||
- cast<PHINode>(CondCmp->getOperand(0))->getParent() != BB) {
+ if (!LVI &&
+ (!isa<PHINode>(CondCmp->getOperand(0)) ||
+ cast<PHINode>(CondCmp->getOperand(0))->getParent() != BB)) {
// If we have a comparison, loop over the predecessors to see if there is
// a condition with a lexically identical value.
pred_iterator PI = pred_begin(BB), E = pred_end(BB);