[X86] Improve comment

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217885 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/X86/X86ISelDAGToDAG.cpp b/lib/Target/X86/X86ISelDAGToDAG.cpp
index 446a38247da8c119114473152b27284bc72039a2..a8587cd9a2a7ebf18cd7dfdea1b45a7beec0322b 100644 (file)
--- a/lib/Target/X86/X86ISelDAGToDAG.cpp
+++ b/lib/Target/X86/X86ISelDAGToDAG.cpp
@@ -775,9 +775,10 @@ static void InsertDAGNode(SelectionDAG &DAG, SDValue Pos, SDValue N) {
   }
 }
 
-// Transform "(X >> (8-C1)) & C2" to "(X >> 8) & 0xff)" if safe. This
-// allows us to convert the shift and and into an h-register extract and
-// a scaled index. Returns false if the simplification is performed.
+// Transform "(X >> (8-C1)) & (0xff << C1)" to "((X >> 8) & 0xff) << C1" if
+// safe. This allows us to convert the shift and and into an h-register
+// extract and a scaled index. Returns false if the simplification is
+// performed.
 static bool FoldMaskAndShiftToExtract(SelectionDAG &DAG, SDValue N,
                                       uint64_t Mask,
                                       SDValue Shift, SDValue X,