[llvm] r183314 - ARMInstrInfo: Improve isSwiftFastImmShift

[Arnold Schwaighofer]

Author: arnolds
Date: Wed Jun  5 09:59:36 2013
New Revision: 183314

URL: http://llvm.org/viewvc/llvm-project?rev=183314&view=rev
Log:
ARMInstrInfo: Improve isSwiftFastImmShift

An instruction with less than 3 inputs is trivially a fast immediate shift.

Reapply of 183256, should not have caused the tablegen segfault on linux either.

Modified:
    llvm/trunk/lib/Target/ARM/ARMBaseInstrInfo.cpp

Modified: llvm/trunk/lib/Target/ARM/ARMBaseInstrInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMBaseInstrInfo.cpp?rev=183314&r1=183313&r2=183314&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/ARMBaseInstrInfo.cpp (original)
+++ llvm/trunk/lib/Target/ARM/ARMBaseInstrInfo.cpp Wed Jun  5 09:59:36 2013
@@ -4152,6 +4152,8 @@ bool ARMBaseInstrInfo::hasNOP() const {
 }
 
 bool ARMBaseInstrInfo::isSwiftFastImmShift(const MachineInstr *MI) const {
+  if (MI->getNumOperands() < 4)
+    return true;
   unsigned ShOpVal = MI->getOperand(3).getImm();
   unsigned ShImm = ARM_AM::getSORegOffset(ShOpVal);
   // Swift supports faster shifts for: lsl 2, lsl 1, and lsr 1.