From: Xavier Leroy <Xavier.Leroy@inria.fr>
To: gava@univ-paris12.fr
Cc: Jacques Garrigue <garrigue@math.nagoya-u.ac.jp>,
caml-list@yquem.inria.fr
Subject: Re: [Caml-list] Multiplication of matrix in C and OCaml
Date: Thu, 08 Feb 2007 11:45:46 +0100 [thread overview]
Message-ID: <45CAFF5A.2020607@inria.fr> (raw)
In-Reply-To: <45CAF3E2.7020807@univ-paris12.fr>
> In the file, I give how I compile, How I run and the result. Here C is 5
> time faster than OCaml
> Many thanks to tell me why my OCaml code is so slow.
Because, as Jacques told you already, your C code is wrong. "add" and
"mult" invoke undefined behaviors of C and therefore gcc feels free to
optimize these functions as no-ops at optimization levels 1 and above.
That's a major speedup, for sure. Why don't you check your code for
correctness first before drawing conclusions on performance?
- Xavier Leroy
next prev parent reply other threads:[~2007-02-08 10:46 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-02-07 23:42 Frédéric Gava
2007-02-08 2:14 ` [Caml-list] " Jacques Garrigue
2007-02-08 9:27 ` Frédéric Gava
2007-02-08 9:38 ` Frédéric Gava
2007-02-08 12:08 ` Jacques Garrigue
2007-02-08 9:56 ` Frédéric Gava
2007-02-08 10:45 ` Xavier Leroy [this message]
2007-02-08 15:16 ` Frédéric Gava
2007-02-09 2:58 ` Jacques Garrigue
2007-02-09 9:06 ` ls-ocaml-developer-2006
2007-02-09 10:32 ` ls-ocaml-developer-2006
2007-02-09 14:22 ` skaller
2007-02-09 21:47 ` ls-ocaml-developer-2006
2007-02-09 21:55 ` Andrej Bauer
2007-02-09 22:36 ` ls-ocaml-developer-2006
2007-02-09 23:53 ` Jon Harrop
2007-02-10 1:41 ` ls-ocaml-developer-2006
2007-02-10 2:24 ` Jon Harrop
2007-02-10 14:41 ` ls-ocaml-developer-2006
2007-02-10 14:52 ` Jon Harrop
2007-02-10 15:51 ` ls-ocaml-developer-2006
2007-02-10 16:10 ` Xavier Leroy
2007-02-10 16:11 ` Jon Harrop
2007-02-10 14:55 ` Mattias Engdegård
2007-02-11 13:13 ` Christophe Raffalli
2007-02-10 1:10 ` Brian Hurt
2007-02-10 1:16 ` Robert Roessler
2007-02-09 23:56 ` Jon Harrop
2007-02-09 12:05 ` Jon Harrop
2007-02-09 12:35 ` ls-ocaml-developer-2006
2007-02-09 13:50 ` Brian Hurt
2007-02-09 14:23 ` Gerd Stolpmann
2007-02-09 14:24 Frederic GAVA
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