Fix PR3874 by restoring a condition I removed, but making it more
precise than it used to be.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67662 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index f631d61..1f80444 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -6582,7 +6582,8 @@
// preferable because it allows the C<<Y expression to be hoisted out
// of a loop if Y is invariant and X is not.
if (Shift && Shift->hasOneUse() && RHSV == 0 &&
- ICI.isEquality() && !Shift->isArithmeticShift()) {
+ ICI.isEquality() && !Shift->isArithmeticShift() &&
+ !isa<Constant>(Shift->getOperand(0))) {
// Compute C << Y.
Value *NS;
if (Shift->getOpcode() == Instruction::LShr) {