[X86] Add support for lowering v4i64 and v8i64 shuffles directly to PALIGNR. I think shuffle combine can figure it out later, but we should try to get it right up front.

llvm-svn: 284914

1 files changed, 8 insertions, 0 deletions

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 94427fa44b7..a11c34b1fbe 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -11450,6 +11450,10 @@ static SDValue lowerV4I64VectorShuffle(const SDLoc &DL, ArrayRef<int> Mask,
                                                 Subtarget, DAG))
     return Shift;
 
+  if (SDValue Rotate = lowerVectorShuffleAsByteRotate(DL, MVT::v4i64, V1, V2,
+                                                      Mask, Subtarget, DAG))
+    return Rotate;
+
   // Use dedicated unpack instructions for masks that match their pattern.
   if (SDValue V =
           lowerVectorShuffleWithUNPCK(DL, MVT::v4i64, Mask, V1, V2, DAG))
@@ -12028,6 +12032,10 @@ static SDValue lowerV8I64VectorShuffle(const SDLoc &DL, ArrayRef<int> Mask,
                                                 Subtarget, DAG))
     return Shift;
 
+  if (SDValue Rotate = lowerVectorShuffleAsByteRotate(DL, MVT::v8i64, V1, V2,
+                                                      Mask, Subtarget, DAG))
+    return Rotate;
+
   if (SDValue Unpck =
           lowerVectorShuffleWithUNPCK(DL, MVT::v8i64, Mask, V1, V2, DAG))
     return Unpck;