------- Comment #1 from burnus at gcc dot gnu dot org 2010-08-01 16:52 -------
! --- FOUR ---- (also occurs for Octopus)
subroutine t2(b,c)
implicit none
REAL :: b(3,3),c(3)
c = matmul(b, c)
end subroutine
That's a pattern I see quite often: LHS variable on the RHS as second (or
first) argument to MATMUL. However, no temporary is needed - but one probably
needs to handle this carefully and it depends how one generates the MATMUL
internally. While most implementation ways should work, one probably can
program it such that avoiding a temporary will lead to wrong results ...
Additionally, one should confirm that it works with-fexternal-blas
As a variant: The same but with one or two items TRANSPOSEd - or CONJugated.
! --- FIVE --- (Found in octopus, www.tddft.org [GPL])
if(any(shape(a).ne.shape(b))) then
That generates two temporaries - one for each SHAPE.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45159
