Assigning a SymmetricMatrix to a symmetric sumbatrix of another SymmetrixMatrix uses a temporary matrix for evaluation

[Mikhail Katliar]

Example:

using namespace blaze;

SymmetricMatrix<StaticMatrix<double, 5, 5, columnMajor>> A;
randomize(A);

SymmetricMatrix<StaticMatrix<double, 4, 4, columnMajor>> B;
randomize(B);

submatrix<1, 1, 4, 4>(A) += B; // <-- evaluates a temporary for A + B

Here, during the add-assignment in line 9 a temporary matrix is used (which degrades the performance):

if( ( ( IsSymmetric_v<MT> || IsHermitian_v<MT> ) && hasOverlap() ) ||
    (~rhs).canAlias( &matrix_ ) ) {
  const AddType tmp( *this + (~rhs) );
  smpAssign( left, tmp );
}
else {
  smpAddAssign( left, ~rhs );
}

The if condition is true because the matrix is symmetric and hasOverlap() returns true.

[Klaus Iglberger]

Hi Misha!

Thanks for reporting this defect. You are correct, in this special case the temporary is not required. We will fix this as quickly as possible.

Best regards,

Klaus!