Add ShiftInst::isLogical/ArithmeticShift methods.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30445 91177308-0d34-0410-b5e6-96231b3b80d8

lib/VMCore/Instructions.cpp

@@ -1141,6 +1141,17 @@ bool BinaryOperator::swapOperands() {
 }
 
 
+//===----------------------------------------------------------------------===//
+//                               ShiftInst Class
+//===----------------------------------------------------------------------===//
+
+/// isLogicalShift - Return true if this is a logical shift left or a logical
+/// shift right.
+bool ShiftInst::isLogicalShift() const {
+  return getOpcode() == Instruction::Shl || getType()->isUnsigned();
+}
+
+
 //===----------------------------------------------------------------------===//
 //                             SetCondInst Class
 //===----------------------------------------------------------------------===//