assert(MVT::isVector(VT) && !MVT::isVector(Operand.getValueType()) &&
MVT::getVectorElementType(VT) == Operand.getValueType() &&
"Illegal SCALAR_TO_VECTOR node!");
+ if (OpOpcode == ISD::UNDEF)
+ return getNode(ISD::UNDEF, VT);
+ // scalar_to_vector(extract_vector_elt V, 0) -> V, top bits are undefined.
+ if (OpOpcode == ISD::EXTRACT_VECTOR_ELT &&
+ isa<ConstantSDNode>(Operand.getOperand(1)) &&
+ Operand.getConstantOperandVal(1) == 0 &&
+ Operand.getOperand(0).getValueType() == VT)
+ return Operand.getOperand(0);
break;
case ISD::FNEG:
if (OpOpcode == ISD::FSUB) // -(X-Y) -> (Y-X)
case ISD::EXTRACT_VECTOR_ELT:
assert(N2C && "Bad EXTRACT_VECTOR_ELT!");
+ // EXTRACT_VECTOR_ELT of an UNDEF is an UNDEF.
+ if (N1.getOpcode() == ISD::UNDEF)
+ return getNode(ISD::UNDEF, VT);
+
// EXTRACT_VECTOR_ELT of CONCAT_VECTORS is often formed while lowering is
// expanding copies of large vectors from registers.
if (N1.getOpcode() == ISD::CONCAT_VECTORS &&
// expanding large vector constants.
if (N1.getOpcode() == ISD::BUILD_VECTOR)
return N1.getOperand(N2C->getValue());
-
+
// EXTRACT_VECTOR_ELT of INSERT_VECTOR_ELT is often formed when vector
// operations are lowered to scalars.
if (N1.getOpcode() == ISD::INSERT_VECTOR_ELT)