http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48025
Summary: Unnecessary function evaluations in arguments to size
and ubound
Product: gcc
Version: 4.6.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: enhancement
Priority: P3
Component: fortran
AssignedTo: [email protected]
ReportedBy: [email protected]
ig25@linux-fd1f:~/Krempel/Size> cat size.f90
subroutine foo(a,b,n,m,k, i)
implicit none
integer, intent(in) :: n
real, dimension(n,n) :: a,b
integer, intent(out) :: m,k,i
m = size(matmul(a,b))
k = size(sum(a,1))
i = size(maxloc(a,1))
m = ubound(matmul(a,b),1)
k = ubound(sum(a,1),1)
i = ubound(maxloc(a,1),1)
end
ig25@linux-fd1f:~/Krempel/Size> gfortran -S -O -fdump-tree-optimized size.f90
ig25@linux-fd1f:~/Krempel/Size> grep _gfortran size.s
call _gfortran_matmul_r4
call _gfortran_size0
call _gfortran_sum_r4
call _gfortran_maxloc1_4_r4
call _gfortran_matmul_r4
call _gfortran_sum_r4
call _gfortran_maxloc1_4_r4
None of the function calls is needed to calculate the size; this
could be done during simplification or optimization.
