[llvm] r318892 - [X86] Simplify some bitmasking and use llvm_unreachable to mark an impossible case. NFC

[Craig Topper via llvm-commits]

Author: ctopper
Date: Wed Nov 22 19:23:59 2017
New Revision: 318892

URL: http://llvm.org/viewvc/llvm-project?rev=318892&view=rev
Log:
[X86] Simplify some bitmasking and use llvm_unreachable to mark an impossible case. NFC

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=318892&r1=318891&r2=318892&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Wed Nov 22 19:23:59 2017
@@ -8112,8 +8112,8 @@ X86TargetLowering::LowerBUILD_VECTOR(SDV
     }
 
     for (unsigned i = 0; i < 2; ++i) {
-      switch ((NonZeros & (0x3 << i*2)) >> (i*2)) {
-        default: break;
+      switch ((NonZeros >> (i*2)) & 0x3) {
+        default: llvm_unreachable("Unexpected NonZero count");
         case 0:
           Ops[i] = Ops[i*2];  // Must be a zero vector.
           break;