Simplify some logic in ComputeMaskedBits. And change ComputeMaskedBits
to pass the mask APInt by value, not by reference. 


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47096 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/Sparc/SparcISelDAGToDAG.cpp b/lib/Target/Sparc/SparcISelDAGToDAG.cpp
index 81e1539..29fe6a4 100644
--- a/lib/Target/Sparc/SparcISelDAGToDAG.cpp
+++ b/lib/Target/Sparc/SparcISelDAGToDAG.cpp
@@ -110,7 +110,7 @@
     /// in Mask are known to be either zero or one and return them in the 
     /// KnownZero/KnownOne bitsets.
     virtual void computeMaskedBitsForTargetNode(const SDOperand Op,
-                                                APInt Mask,
+                                                const APInt &Mask,
                                                 APInt &KnownZero, 
                                                 APInt &KnownOne,
                                                 const SelectionDAG &DAG,
@@ -270,7 +270,7 @@
 /// be zero. Op is expected to be a target specific node. Used by DAG
 /// combiner.
 void SparcTargetLowering::computeMaskedBitsForTargetNode(const SDOperand Op,
-                                                         APInt Mask,
+                                                         const APInt &Mask,
                                                          APInt &KnownZero, 
                                                          APInt &KnownOne,
                                                          const SelectionDAG &DAG,