public inbox for gcc-bugs@sourceware.org help / color / mirror / Atom feed
From: "pinskia at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug fortran/31139] sum(w_re(1:nn,1)*fi(i(1:nn, ii))) up to 3.5x slower than C version Date: Mon, 12 Mar 2007 05:33:00 -0000 [thread overview] Message-ID: <20070312053328.22004.qmail@sourceware.org> (raw) In-Reply-To: <bug-31139-13404@http.gcc.gnu.org/bugzilla/> ------- Comment #3 from pinskia at gcc dot gnu dot org 2007-03-12 05:33 ------- The problem here is obvious, in the Fortran case, there is a temp array being created while in the C case, there is not. Also in the optimized C case, the multiplication of the complex numbers is incorrect unless you add -ffast-math. Actually I think in both C cases it is incorrect. Can someone try with -ffast-math for both the C and Fortran cases? complex * complex is not a simple cross product in FP world. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31139
next prev parent reply other threads:[~2007-03-12 5:33 UTC|newest] Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top 2007-03-11 22:38 [Bug fortran/31139] New: " burnus at gcc dot gnu dot org 2007-03-11 22:45 ` [Bug fortran/31139] " burnus at gcc dot gnu dot org 2007-03-11 22:50 ` burnus at gcc dot gnu dot org 2007-03-12 5:33 ` pinskia at gcc dot gnu dot org [this message] 2007-03-12 5:38 ` pinskia at gcc dot gnu dot org 2007-03-12 7:58 ` burnus at gcc dot gnu dot org 2007-03-12 8:16 ` burnus at gcc dot gnu dot org 2007-04-18 5:56 ` fxcoudert at gcc dot gnu dot org 2010-09-12 15:45 ` jvdelisle at gcc dot gnu dot org [not found] <bug-31139-4@http.gcc.gnu.org/bugzilla/> 2013-06-22 16:55 ` dominiq at lps dot ens.fr 2015-10-10 9:21 ` dominiq at lps dot ens.fr
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20070312053328.22004.qmail@sourceware.org \ --to=gcc-bugzilla@gcc.gnu.org \ --cc=gcc-bugs@gcc.gnu.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).