This is the mail archive of the
gcc-bugs@gcc.gnu.org
mailing list for the GCC project.
[Bug target/36241] Executable compiled with -m64 almost three times faster than the one compiled with -m32 on Core2Duo
- From: "ubizjak at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 15 May 2008 09:21:53 -0000
- Subject: [Bug target/36241] Executable compiled with -m64 almost three times faster than the one compiled with -m32 on Core2Duo
- References: <bug-36241-12313@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #2 from ubizjak at gmail dot com 2008-05-15 09:21 -------
This regression is due to store forwarding penalty:
...
movl %esi, -408(%ebp)
movl %edi, -404(%ebp)
fldl -408(%ebp)
...
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36241