From: Owen Anderson <resistor@mac.com>
Date: Fri, 16 Sep 2011 23:04:48 +0000 (+0000)
Subject: Fix bitfield decoding based on Eli's feedback.
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=8b22778431cdeb112366ed5dc6283b3a7af19018;p=oota-llvm.git

Fix bitfield decoding based on Eli's feedback.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139969 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Target/ARM/Disassembler/ARMDisassembler.cpp b/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
index d1eb5b3004b..4e9c3e58a5f 100644
--- a/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
+++ b/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
@@ -1004,10 +1004,9 @@ static DecodeStatus DecodeBitfieldMaskOperand(llvm::MCInst &Inst, unsigned Val,
   unsigned msb = fieldFromInstruction32(Val, 5, 5);
   unsigned lsb = fieldFromInstruction32(Val, 0, 5);
 
-  uint32_t msb_mask = (1 << (msb+1)) - 1;
-  if (msb == 31) msb_mask = 0xFFFFFFFF;
-  uint32_t lsb_mask = (1 << lsb) - 1;
-  if (lsb == 31) lsb_mask = 0xFFFFFFFF;
+  uint32_t msb_mask = 0xFFFFFFFF;
+  if (msb != 31) msb_mask = (1U << (msb+1)) - 1;
+  uint32_t lsb_mask = (1U << lsb) - 1;
 
   Inst.addOperand(MCOperand::CreateImm(~(msb_mask ^ lsb_mask)));
   return MCDisassembler::Success;