Comment fix

llvm-svn: 259990

llvm/lib/Target/X86/X86ISelLowering.cpp

@@ -10652,7 +10652,7 @@ static SDValue lowerVectorShuffleWithUndefHalf(SDLoc DL, MVT VT, SDValue V1,
                        DAG.getIntPtrConstant(HalfNumElts, DL));
   }
 
-  // If the shuffle only uses the lower halves of the input operands,
+  // If the shuffle only uses two of the four halves of the input operands,
   // then extract them and perform the 'half' shuffle at half width.
   // e.g. vector_shuffle <X, X, X, X, u, u, u, u> or <X, X, u, u>
   int HalfIdx1 = -1, HalfIdx2 = -1;