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[Bug libfortran/33985] access="stream",form="unformatted" doesn't buffer
- From: "jvdelisle at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 2 Dec 2007 18:55:41 -0000
- Subject: [Bug libfortran/33985] access="stream",form="unformatted" doesn't buffer
- References: <bug-33985-10391@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #26 from jvdelisle at gcc dot gnu dot org 2007-12-02 18:55 -------
With this test case:
program main
implicit none
integer :: i, j
open(95,form="unformatted",access="stream")
do j=1, 125000
do i=0,255
write(95) int(i,kind=1)
end do
end do
end program main
gfortran 4.3 with patch
$ gfc pr33985.f90
$ time ./a.out
real 0m5.823s
user 0m5.781s
sys 0m0.029s
gfortran 4.2 no patch
$ gfc42 -static pr33985.f90
$ time ./a.out
real 1m8.781s
user 0m10.334s
sys 0m58.446s
Thats an 11.8 X improvement.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33985