[TII] Allow getMemOpBaseRegImmOfs() to accept negative offsets. NFC.

http://reviews.llvm.org/D17967

llvm-svn: 263021
diff --git a/llvm/lib/Target/X86/X86InstrInfo.cpp b/llvm/lib/Target/X86/X86InstrInfo.cpp
index fc43d9b..dbfa8ac 100644
--- a/llvm/lib/Target/X86/X86InstrInfo.cpp
+++ b/llvm/lib/Target/X86/X86InstrInfo.cpp
@@ -4612,7 +4612,7 @@
 }
 
 bool X86InstrInfo::getMemOpBaseRegImmOfs(MachineInstr *MemOp, unsigned &BaseReg,
-                                         unsigned &Offset,
+                                         int64_t &Offset,
                                          const TargetRegisterInfo *TRI) const {
   const MCInstrDesc &Desc = MemOp->getDesc();
   int MemRefBegin = X86II::getMemoryOperandNo(Desc.TSFlags, MemOp->getOpcode());