Update the comments for ComputeMaskedBits, which lost its Mask parameter
in r154011.

llvm-svn: 208757
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index 07720d7..e684dc8 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -211,7 +211,7 @@
 
   KnownZero = APInt::getHighBitsSet(BitWidth, MinLeadingZeros);
 }
-/// ComputeMaskedBits - Determine which of the bits are known to be either zero
+/// ComputeMaskedBits - Determine which bits of V are known to be either zero
 /// or one and return them in the KnownZero/KnownOne bit sets.
 ///
 /// NOTE: we cannot consider 'undef' to be "IsZero" here.  The problem is that
@@ -241,7 +241,7 @@
           V->getType()->getScalarSizeInBits() == BitWidth) &&
          KnownZero.getBitWidth() == BitWidth &&
          KnownOne.getBitWidth() == BitWidth &&
-         "V, Mask, KnownOne and KnownZero should have same BitWidth");
+         "V, KnownOne and KnownZero should have same BitWidth");
 
   if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
     // We know all of the bits for a constant!