https://gcc.gnu.org/bugzilla/show_bug.cgi?id=31593
--- Comment #46 from Thomas Koenig <tkoenig at gcc dot gnu.org> ---
(In reply to Dominique d'Humieres from comment #45)
> Anything left to fix in this PR?
Unfortunately yes...
We still do not take advantage of the fact that the call
to a subroutine cannot change the value of the do loop:
ig25@linux-fd1f:~/Krempel/Do> cat call_unspec.f90
module foo
contains
subroutine output(i1,i2,i3,i4,i5)
integer :: i1,i2,i3,i4,i5
print '(5(I0,:" "))',i1,i2,i3,i4,i5
end subroutine output
end module foo
program main
use foo
implicit none
integer :: value
integer :: p1, p2, p3, p4
integer :: i
do value = 750,800
do i=1, 10
do p1 = 1, value-2
do p2 = p1 + 1, value - p1
do p3 = p2 + 1, (value - (p1 + p2))/2
p4 = value - p1 - p2 - p3
if (p1 * p2 * p3 * p4 == value * 1000000) &
& call output (value, p1, p2, p3, p4)
end do
end do
end do
end do
end do
end program main
ig25@linux-fd1f:~/Krempel/Do> gfortran -O2 call_unspec.f90 && time ./a.out >
/dev/null
real 0m4.586s
user 0m4.578s
sys 0m0.000s
ig25@linux-fd1f:~/Krempel/Do> cat call_intent.f90
module foo
contains
subroutine output(i1,i2,i3,i4,i5)
integer, intent(in) :: i1,i2,i3,i4,i5
print '(5(I0,:" "))',i1,i2,i3,i4,i5
end subroutine output
end module foo
program main
use foo
implicit none
integer :: value
integer :: p1, p2, p3, p4
integer :: i
do value = 750,800
do i=1, 10
do p1 = 1, value-2
do p2 = p1 + 1, value - p1
do p3 = p2 + 1, (value - (p1 + p2))/2
p4 = value - p1 - p2 - p3
if (p1 * p2 * p3 * p4 == value * 1000000) &
& call output(value , p1 , p2 , p3 , p4)
end do
end do
end do
end do
end do
end program main
ig25@linux-fd1f:~/Krempel/Do> gfortran -O2 call_intent.f90 && time ./a.out >
/dev/null
real 0m3.090s
user 0m3.089s
sys 0m0.000s
ig25@linux-fd1f:~/Krempel/Do> cat call_parens.f90
module foo
contains
subroutine output(i1,i2,i3,i4,i5)
print '(5(I0,:" "))',i1,i2,i3,i4,i5
end subroutine output
end module foo
program main
use foo
implicit none
integer :: value
integer :: p1, p2, p3, p4
integer :: i
do value = 750,800
do i=1, 10
do p1 = 1, value-2
do p2 = p1 + 1, value - p1
do p3 = p2 + 1, (value - (p1 + p2))/2
p4 = value - p1 - p2 - p3
if (p1 * p2 * p3 * p4 == value * 1000000) &
& call output((value),(p1),(p2),(p3),(p4))
end do
end do
end do
end do
end do
end program main
ig25@linux-fd1f:~/Krempel/Do> gfortran -O2 call_parens.f90 && time ./a.out >
/dev/null
real 0m3.134s
user 0m3.131s
sys 0m0.000s
