From fffd56ecdf348630bba0e1500229f2fa8d7e8101 Mon Sep 17 00:00:00 2001
From: Alexey Samsonov <vonosmas@gmail.com>
Date: Wed, 20 Aug 2014 21:56:43 +0000
Subject: Fix undefined behavior (left shift of negative value) in SystemZ
 backend.

This bug is reported by UBSan.

llvm-svn: 216131
---
 llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp')

diff --git a/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp b/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp
index db1a005353b..eff4ae3baf3 100644
--- a/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp
+++ b/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp
@@ -294,7 +294,7 @@ static void emitIncrement(MachineBasicBlock &MBB,
     else {
       Opcode = SystemZ::AGFI;
       // Make sure we maintain 8-byte stack alignment.
-      int64_t MinVal = -int64_t(1) << 31;
+      int64_t MinVal = -uint64_t(1) << 31;
       int64_t MaxVal = (int64_t(1) << 31) - 8;
       if (ThisVal < MinVal)
         ThisVal = MinVal;
-- 
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