[TargetLowering] Add ISD::ROTL/ROTR vector expansion

Move existing rotation expansion code into TargetLowering and set it up for vectors as well.

Ideally this would share more of the funnel shift expansion, but we handle the shift amount modulo quite differently at the moment.

Begun removing x86 vector rotate custom lowering to use the expansion.

llvm-svn: 349025

1 files changed, 12 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp
index b8066c1c53b..4df02c6a6bc 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp
@@ -133,6 +133,7 @@ class VectorLegalizer {
   SDValue ExpandCTLZ(SDValue Op);
   SDValue ExpandCTTZ(SDValue Op);
   SDValue ExpandFunnelShift(SDValue Op);
+  SDValue ExpandROT(SDValue Op);
   SDValue ExpandFMINNUM_FMAXNUM(SDValue Op);
   SDValue ExpandStrictFPOp(SDValue Op);
 
@@ -759,6 +760,9 @@ SDValue VectorLegalizer::Expand(SDValue Op) {
   case ISD::FSHL:
   case ISD::FSHR:
     return ExpandFunnelShift(Op);
+  case ISD::ROTL:
+  case ISD::ROTR:
+    return ExpandROT(Op);
   case ISD::FMINNUM:
   case ISD::FMAXNUM:
     return ExpandFMINNUM_FMAXNUM(Op);
@@ -1167,6 +1171,14 @@ SDValue VectorLegalizer::ExpandFunnelShift(SDValue Op) {
   return DAG.UnrollVectorOp(Op.getNode());
 }
 
+SDValue VectorLegalizer::ExpandROT(SDValue Op) {
+  SDValue Result;
+  if (TLI.expandROT(Op.getNode(), Result, DAG))
+    return Result;
+
+  return DAG.UnrollVectorOp(Op.getNode());
+}
+
 SDValue VectorLegalizer::ExpandFMINNUM_FMAXNUM(SDValue Op) {
   if (SDValue Expanded = TLI.expandFMINNUM_FMAXNUM(Op.getNode(), DAG))
     return Expanded;