[CVP] Don't assume Constants of type i1 can be known to be true or false

CVP wants to analyze the condition operand of a select along an edge.
It succeeds in getting back a Constant but not a ConstantInt.  Instead,
it gets a ConstantExpr.  It then assumes that the Constant must be equal
to false because it isn't equal to true.

Instead, perform an additional comparison.

This fixes PR23752.

llvm-svn: 239217

1 files changed, 4 insertions, 3 deletions

diff --git a/llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp b/llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
index d1302c6e22f..79624b2e4c4 100644
--- a/llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
+++ b/llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
@@ -113,10 +113,11 @@ bool CorrelatedValuePropagation::processPHI(PHINode *P) {
 
       Value *Condition = SI->getCondition();
       if (!Condition->getType()->isVectorTy()) {
-        if (Constant *C = LVI->getConstantOnEdge(Condition, P->getIncomingBlock(i), BB, P)) {
-          if (C == ConstantInt::getTrue(Condition->getType())) {
+        if (Constant *C = LVI->getConstantOnEdge(
+                Condition, P->getIncomingBlock(i), BB, P)) {
+          if (C->isOneValue()) {
             V = SI->getTrueValue();
-          } else {
+          } else if (C->isZeroValue()) {
             V = SI->getFalseValue();
           }
           // Once LVI learns to handle vector types, we could also add support