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From: "Thomas dot Koenig at online dot de" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug libfortran/16339] Unformatted i/o on large arrays inefficient Date: Fri, 04 Mar 2005 10:48:00 -0000 [thread overview] Message-ID: <20050304104746.15405.qmail@sourceware.org> (raw) In-Reply-To: <20040703014226.16339.rth@gcc.gnu.org> ------- Additional Comments From Thomas dot Koenig at online dot de 2005-03-04 10:47 ------- This is really _very_ inefficient, by a factor of 20. Some test numbers: $ g77 write-record.f $ time ./a.out real 0m1.819s user 0m1.774s sys 0m0.044s $ gfortran write-record.f $ time ./a.out real 0m43.723s user 0m9.003s sys 0m34.571s $ cat write-record.f program main integer n parameter (n=10000000) real a(n) write (10) (a(i),i=1,n) end $ gfortran -v Using built-in specs. Target: ia64-unknown-linux-gnu Configured with: ../gcc-4.1-20050227/configure --prefix=/home/zfkts --enable-languages=c,f95 Thread model: posix gcc version 4.1.0 20050227 (experimental) By comparison: $ ifort write-record.f $ time ./a.out real 0m0.117s user 0m0.001s sys 0m0.116s -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16339
next prev parent reply other threads:[~2005-03-04 10:48 UTC|newest] Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top 2004-07-03 1:42 [Bug libfortran/16339] New: " rth at gcc dot gnu dot org 2004-07-03 1:43 ` [Bug libfortran/16339] " rth at gcc dot gnu dot org 2004-07-03 1:52 ` pinskia at gcc dot gnu dot org 2005-03-04 10:48 ` Thomas dot Koenig at online dot de [this message] 2005-06-04 17:50 ` jblomqvi at cc dot hut dot fi 2005-06-05 21:19 ` jblomqvi at cc dot hut dot fi [not found] <bug-16339-119@http.gcc.gnu.org/bugzilla/> 2005-10-07 20:02 ` cvs-commit at gcc dot gnu dot org 2005-11-04 19:50 ` fxcoudert at gcc dot gnu dot org 2005-12-09 9:24 ` fxcoudert at gcc dot gnu dot org
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