From bf99a426cb311cd7b1cebb63f28a8e4762fcee4c Mon Sep 17 00:00:00 2001
From: NAKAMURA Takumi <geek4civic@gmail.com>
Date: Wed, 26 Dec 2012 06:43:14 +0000
Subject: [PATCH] TableGen/FixedLenDecoderEmitter.cpp: Fix a potential mask
 overflow in fieldFromInstruction().

Reported by Yang Yongyong, thanks!

llvm-svn: 171101
---
 llvm/utils/TableGen/FixedLenDecoderEmitter.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/llvm/utils/TableGen/FixedLenDecoderEmitter.cpp b/llvm/utils/TableGen/FixedLenDecoderEmitter.cpp
index b2dc87888090..0c3017f38920 100644
--- a/llvm/utils/TableGen/FixedLenDecoderEmitter.cpp
+++ b/llvm/utils/TableGen/FixedLenDecoderEmitter.cpp
@@ -1866,7 +1866,7 @@ static void emitFieldFromInstruction(formatted_raw_ostream &OS) {
      << "    if (numBits == sizeof(InsnType)*8)\n"
      << "      fieldMask = (InsnType)(-1LL);\n"
      << "    else\n"
-     << "      fieldMask = ((1 << numBits) - 1) << startBit;\n"
+     << "      fieldMask = (((InsnType)1 << numBits) - 1) << startBit;\n"
      << "    return (insn & fieldMask) >> startBit;\n"
      << "}\n\n";
 }