[llvm] r314652 - [X86] Cleanup uses of computeKnownBits by using MaskedValueIsZero helper instead. NFCI.

[Simon Pilgrim via llvm-commits]

Author: rksimon
Date: Mon Oct  2 02:08:45 2017
New Revision: 314652

URL: http://llvm.org/viewvc/llvm-project?rev=314652&view=rev
Log:
[X86] Cleanup uses of computeKnownBits by using MaskedValueIsZero helper instead. NFCI.

Modified:
    llvm/trunk/lib/Target/X86/X86ISelLowering.cpp

Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=314652&r1=314651&r2=314652&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Mon Oct  2 02:08:45 2017
@@ -5946,12 +5946,9 @@ static bool getFauxShuffleMask(SDValue N
           DAG.ComputeNumSignBits(N1) <= NumBitsPerElt)
         return false;
     } else {
-      KnownBits Known0, Known1;
-      DAG.computeKnownBits(N0, Known0);
-      if (Known0.countMinLeadingZeros() < NumBitsPerElt)
-        return false;
-      DAG.computeKnownBits(N1, Known1);
-      if (Known1.countMinLeadingZeros() < NumBitsPerElt)
+      APInt ZeroMask = APInt::getHighBitsSet(2 * NumBitsPerElt, NumBitsPerElt);
+      if (!DAG.MaskedValueIsZero(N0, ZeroMask) ||
+          !DAG.MaskedValueIsZero(N1, ZeroMask))
         return false;
     }