[SelectionDAG] Teach LegalizeVectorOps to not unroll CTLZ_ZERO_UNDEF and CTTZ_ZERO_UN...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@256476 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp b/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp
index 4bd0b6b518abcc239861894065484f2ea3a1516e..f61f631e2ff8d667f90c094b9f25363d50df406c 100644 (file)
--- a/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp
@@ -106,6 +106,7 @@ class VectorLegalizer {
   SDValue ExpandStore(SDValue Op);
   SDValue ExpandFNEG(SDValue Op);
   SDValue ExpandBITREVERSE(SDValue Op);
+  SDValue ExpandCTLZ_CTTZ_ZERO_UNDEF(SDValue Op);
 
   /// \brief Implements vector promotion.
   ///
@@ -719,6 +720,9 @@ SDValue VectorLegalizer::Expand(SDValue Op) {
     return UnrollVSETCC(Op);
   case ISD::BITREVERSE:
     return ExpandBITREVERSE(Op);
+  case ISD::CTLZ_ZERO_UNDEF:
+  case ISD::CTTZ_ZERO_UNDEF:
+    return ExpandCTLZ_CTTZ_ZERO_UNDEF(Op);
   default:
     return DAG.UnrollVectorOp(Op.getNode());
   }
@@ -1022,6 +1026,16 @@ SDValue VectorLegalizer::ExpandFNEG(SDValue Op) {
   return DAG.UnrollVectorOp(Op.getNode());
 }
 
+SDValue VectorLegalizer::ExpandCTLZ_CTTZ_ZERO_UNDEF(SDValue Op) {
+  // If the non-ZERO_UNDEF version is supported we can let LegalizeDAG handle.
+  unsigned Opc = Op.getOpcode() == ISD::CTLZ_ZERO_UNDEF ? ISD::CTLZ : ISD::CTTZ;
+  if (TLI.isOperationLegalOrCustom(Opc, Op.getValueType()))
+    return Op;
+
+  // Otherwise go ahead and unroll.
+  return DAG.UnrollVectorOp(Op.getNode());
+}
+
 SDValue VectorLegalizer::UnrollVSETCC(SDValue Op) {
   EVT VT = Op.getValueType();
   unsigned NumElems = VT.getVectorNumElements();