From 6d7ca92bbf1d82905573ed04b015cfebc0f4c965 Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Mon, 18 Sep 2006 18:27:05 +0000
Subject: [PATCH] Fix an infinite loop building the CFE

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30465 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/Scalar/InstructionCombining.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index c3d6f1465eb..7a3b97783b2 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -3988,7 +3988,8 @@ Instruction *InstCombiner::visitSetCondInst(SetCondInst &I) {
           // 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() && CI->isNullValue() &&
-              I.isEquality() && !Shift->isArithmeticShift()) {
+              I.isEquality() && !Shift->isArithmeticShift() &&
+              isa<Instruction>(Shift->getOperand(0))) {
             // Compute C << Y.
             Value *NS;
             if (Shift->getOpcode() == Instruction::Shr) {
-- 
2.34.1