Reintroduce r135730, this is indeed the right approach, there is no
native 256-bit vector instruction to do scalar_to_vector.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136001 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index d2c8778..0b5ac6a 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -983,6 +983,7 @@
setOperationAction(ISD::VECTOR_SHUFFLE, SVT, Custom);
setOperationAction(ISD::INSERT_VECTOR_ELT, SVT, Custom);
setOperationAction(ISD::EXTRACT_VECTOR_ELT, SVT, Custom);
+ setOperationAction(ISD::SCALAR_TO_VECTOR, SVT, Custom);
setOperationAction(ISD::INSERT_SUBVECTOR, SVT, Custom);
}
@@ -6324,9 +6325,26 @@
SDValue
X86TargetLowering::LowerSCALAR_TO_VECTOR(SDValue Op, SelectionDAG &DAG) const {
+ LLVMContext *Context = DAG.getContext();
DebugLoc dl = Op.getDebugLoc();
EVT OpVT = Op.getValueType();
+ // If this is a 256-bit vector result, first insert into a 128-bit
+ // vector and then insert into the 256-bit vector.
+ if (OpVT.getSizeInBits() > 128) {
+ // Insert into a 128-bit vector.
+ EVT VT128 = EVT::getVectorVT(*Context,
+ OpVT.getVectorElementType(),
+ OpVT.getVectorNumElements() / 2);
+
+ Op = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT128, Op.getOperand(0));
+
+ // Insert the 128-bit vector.
+ return Insert128BitVector(DAG.getNode(ISD::UNDEF, dl, OpVT), Op,
+ DAG.getConstant(0, MVT::i32),
+ DAG, dl);
+ }
+
if (Op.getValueType() == MVT::v1i64 &&
Op.getOperand(0).getValueType() == MVT::i64)
return DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, MVT::v1i64, Op.getOperand(0));