Implement temporary-free path for "D.nolias() ?= C + A*B". (I thought it was already implemented)

This commit is contained in:
Gael Guennebaud
2015-10-09 15:28:09 +02:00
parent a4cc4c1e5e
commit 6536b4bad7
5 changed files with 47 additions and 19 deletions

View File

@@ -187,6 +187,37 @@ struct Assignment<DstXprType, CwiseUnaryOp<internal::scalar_multiple_op<ScalarBi
}
};
//----------------------------------------
// Catch "Dense ?= xpr + Product<>" expression to save one temporary
// FIXME we could probably enable these rules for any product, i.e., not only Dense and DefaultProduct
template<typename DstXprType, typename OtherXpr, typename ProductType, typename Scalar, typename Func1, typename Func2>
struct assignment_from_xpr_plus_product
{
typedef CwiseBinaryOp<internal::scalar_sum_op<Scalar>, const OtherXpr, const ProductType> SrcXprType;
static void run(DstXprType &dst, const SrcXprType &src, const Func1& func)
{
call_assignment_no_alias(dst, src.lhs(), func);
call_assignment_no_alias(dst, src.rhs(), Func2());
}
};
template< typename DstXprType, typename OtherXpr, typename Lhs, typename Rhs, typename Scalar>
struct Assignment<DstXprType, CwiseBinaryOp<internal::scalar_sum_op<Scalar>, const OtherXpr,
const Product<Lhs,Rhs,DefaultProduct> >, internal::assign_op<Scalar>, Dense2Dense>
: assignment_from_xpr_plus_product<DstXprType, OtherXpr, Product<Lhs,Rhs,DefaultProduct>, Scalar, internal::assign_op<Scalar>, internal::add_assign_op<Scalar> >
{};
template< typename DstXprType, typename OtherXpr, typename Lhs, typename Rhs, typename Scalar>
struct Assignment<DstXprType, CwiseBinaryOp<internal::scalar_sum_op<Scalar>, const OtherXpr,
const Product<Lhs,Rhs,DefaultProduct> >, internal::add_assign_op<Scalar>, Dense2Dense>
: assignment_from_xpr_plus_product<DstXprType, OtherXpr, Product<Lhs,Rhs,DefaultProduct>, Scalar, internal::add_assign_op<Scalar>, internal::add_assign_op<Scalar> >
{};
template< typename DstXprType, typename OtherXpr, typename Lhs, typename Rhs, typename Scalar>
struct Assignment<DstXprType, CwiseBinaryOp<internal::scalar_sum_op<Scalar>, const OtherXpr,
const Product<Lhs,Rhs,DefaultProduct> >, internal::sub_assign_op<Scalar>, Dense2Dense>
: assignment_from_xpr_plus_product<DstXprType, OtherXpr, Product<Lhs,Rhs,DefaultProduct>, Scalar, internal::sub_assign_op<Scalar>, internal::sub_assign_op<Scalar> >
{};
//----------------------------------------
template<typename Lhs, typename Rhs>
struct generic_product_impl<Lhs,Rhs,DenseShape,DenseShape,InnerProduct>