[DAGCombine] Fold insert_subvector(bitcast(x),bitcast(y),c1) -> bitcast(insert_subvector(x,y),c2)

Move this combine from x86 into generic DAGCombine, which currently only manages cases where the bitcast is between types of the same scalarsize.

Differential Revision: https://reviews.llvm.org/D59188

llvm-svn: 362324

1 files changed, 0 insertions, 36 deletions

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 253f4487976..5bdcb89b8f5 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -43066,42 +43066,6 @@ static SDValue combineInsertSubvector(SDNode *N, SelectionDAG &DAG,
     }
   }
 
-  // Push subvector bitcasts to the output, adjusting the index as we go.
-  // insert_subvector(bitcast(v), bitcast(s), c1) ->
-  // bitcast(insert_subvector(v,s,c2))
-  // TODO: Move this to generic - which only supports same scalar sizes.
-  if ((Vec.isUndef() || Vec.getOpcode() == ISD::BITCAST) &&
-      SubVec.getOpcode() == ISD::BITCAST) {
-    SDValue VecSrc = peekThroughBitcasts(Vec);
-    SDValue SubVecSrc = peekThroughBitcasts(SubVec);
-    MVT VecSrcSVT = VecSrc.getSimpleValueType().getScalarType();
-    MVT SubVecSrcSVT = SubVecSrc.getSimpleValueType().getScalarType();
-    if (Vec.isUndef() || VecSrcSVT == SubVecSrcSVT) {
-      MVT NewOpVT;
-      SDValue NewIdx;
-      unsigned NumElts = OpVT.getVectorNumElements();
-      unsigned EltSizeInBits = OpVT.getScalarSizeInBits();
-      if ((EltSizeInBits % SubVecSrcSVT.getSizeInBits()) == 0) {
-        unsigned Scale = EltSizeInBits / SubVecSrcSVT.getSizeInBits();
-        NewOpVT = MVT::getVectorVT(SubVecSrcSVT, NumElts * Scale);
-        NewIdx = DAG.getIntPtrConstant(IdxVal * Scale, dl);
-      } else if ((SubVecSrcSVT.getSizeInBits() % EltSizeInBits) == 0) {
-        unsigned Scale = SubVecSrcSVT.getSizeInBits() / EltSizeInBits;
-        if ((IdxVal % Scale) == 0) {
-          NewOpVT = MVT::getVectorVT(SubVecSrcSVT, NumElts / Scale);
-          NewIdx = DAG.getIntPtrConstant(IdxVal / Scale, dl);
-        }
-      }
-      if (NewIdx && DAG.getTargetLoweringInfo().isOperationLegal(
-                        ISD::INSERT_SUBVECTOR, NewOpVT)) {
-        SDValue Res = DAG.getBitcast(NewOpVT, VecSrc);
-        Res = DAG.getNode(ISD::INSERT_SUBVECTOR, dl, NewOpVT, Res, SubVecSrc,
-                          NewIdx);
-        return DAG.getBitcast(OpVT, Res);
-      }
-    }
-  }
-
   // Match concat_vector style patterns.
   SmallVector<SDValue, 2> SubVectorOps;
   if (collectConcatOps(N, SubVectorOps))