From: Ulrich Weigand <ulrich.weigand@de.ibm.com>
Date: Thu, 1 Dec 2016 18:00:50 +0000 (+0000)
Subject: [SystemZ] Fix fallout from r288374
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=a0c671e0382f67bcc55990fa57a15fd6949b78ee;p=llvm

[SystemZ] Fix fallout from r288374

Avoid undefined behavior due to too-large shift count.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@288391 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Target/SystemZ/MCTargetDesc/SystemZMCAsmBackend.cpp b/lib/Target/SystemZ/MCTargetDesc/SystemZMCAsmBackend.cpp
index 1f3cdde1d74..9192448afd0 100644
--- a/lib/Target/SystemZ/MCTargetDesc/SystemZMCAsmBackend.cpp
+++ b/lib/Target/SystemZ/MCTargetDesc/SystemZMCAsmBackend.cpp
@@ -101,7 +101,8 @@ void SystemZMCAsmBackend::applyFixup(const MCFixup &Fixup, char *Data,
 
   // Big-endian insertion of Size bytes.
   Value = extractBitsForFixup(Kind, Value);
-  Value &= ((uint64_t)1 << BitSize) - 1;
+  if (BitSize < 64)
+    Value &= ((uint64_t)1 << BitSize) - 1;
   unsigned ShiftValue = (Size * 8) - 8;
   for (unsigned I = 0; I != Size; ++I) {
     Data[Offset + I] |= uint8_t(Value >> ShiftValue);