Fix integer undefined behavior due to signed left shift overflow in LLVM.
Reviewed offline by chandlerc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162623 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelDAGToDAG.cpp b/lib/Target/X86/X86ISelDAGToDAG.cpp
index 27195b4..b7b4002 100644
--- a/lib/Target/X86/X86ISelDAGToDAG.cpp
+++ b/lib/Target/X86/X86ISelDAGToDAG.cpp
@@ -1011,7 +1011,7 @@
AM.IndexReg = ShVal.getNode()->getOperand(0);
ConstantSDNode *AddVal =
cast<ConstantSDNode>(ShVal.getNode()->getOperand(1));
- uint64_t Disp = AddVal->getSExtValue() << Val;
+ uint64_t Disp = (uint64_t)AddVal->getSExtValue() << Val;
if (!FoldOffsetIntoAddress(Disp, AM))
return false;
}
@@ -2116,7 +2116,8 @@
// Make sure that we don't change the operation by removing bits.
// This only matters for OR and XOR, AND is unaffected.
- if (Opcode != ISD::AND && ((Val >> ShlVal) << ShlVal) != Val)
+ uint64_t RemovedBitsMask = (1ULL << ShlVal) - 1;
+ if (Opcode != ISD::AND && (Val & RemovedBitsMask) != 0)
break;
unsigned ShlOp, Op;