Move ComputeMaskedBits, MaskedValueIsZero, and ComputeNumSignBits from

TargetLowering to SelectionDAG so that they have more convenient
access to the current DAG, in preparation for the ValueType routines
being changed from standalone functions to members of SelectionDAG for
the pre-legalize vector type changes.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37704 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/Alpha/AlphaISelDAGToDAG.cpp

@@ -90,7 +90,7 @@ namespace {
       // see if the missing bits (0x1000) are already known zero if not, the zap
       // isn't okay to do, as it won't clear all the required bits.
       if (BitsToCheck &&
-          !getTargetLowering().MaskedValueIsZero(LHS, BitsToCheck))
+          !CurDAG->MaskedValueIsZero(LHS, BitsToCheck))
         return 0;
       
       return Result;