[ConstantFold] Fix misfolding of icmp with a bitcast FP second operand.

In the process of trying to eliminate the bitcast, this was producing a
malformed icmp with FP operands.

Differential revision: https://reviews.llvm.org/D51215

llvm-svn: 354380

1 files changed, 4 insertions, 2 deletions

diff --git a/llvm/lib/IR/ConstantFold.cpp b/llvm/lib/IR/ConstantFold.cpp
index 748a2ce475f..2c958c7dd49 100644
--- a/llvm/lib/IR/ConstantFold.cpp
+++ b/llvm/lib/IR/ConstantFold.cpp
@@ -1980,11 +1980,13 @@ Constant *llvm::ConstantFoldCompareInstruction(unsigned short pred,
 
     // If the right hand side is a bitcast, try using its inverse to simplify
     // it by moving it to the left hand side.  We can't do this if it would turn
-    // a vector compare into a scalar compare or visa versa.
+    // a vector compare into a scalar compare or visa versa, or if it would turn
+    // the operands into FP values.
     if (ConstantExpr *CE2 = dyn_cast<ConstantExpr>(C2)) {
       Constant *CE2Op0 = CE2->getOperand(0);
       if (CE2->getOpcode() == Instruction::BitCast &&
-          CE2->getType()->isVectorTy() == CE2Op0->getType()->isVectorTy()) {
+          CE2->getType()->isVectorTy() == CE2Op0->getType()->isVectorTy() &&
+          !CE2Op0->getType()->isFPOrFPVectorTy()) {
         Constant *Inverse = ConstantExpr::getBitCast(C1, CE2Op0->getType());
         return ConstantExpr::getICmp(pred, Inverse, CE2Op0);
       }