This is the mail archive of the
gcc-bugs@gcc.gnu.org
mailing list for the GCC project.
[Bug tree-optimization/38785] huge performance regression on EEMBC bitmnp01
- From: "steven at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 9 Jan 2009 20:55:18 -0000
- Subject: [Bug tree-optimization/38785] huge performance regression on EEMBC bitmnp01
- References: <bug-38785-5394@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #5 from steven at gcc dot gnu dot org 2009-01-09 20:55 -------
Joern, re. comment #4, Richi refers to my patch to enable PRE at -Os, see [1].
An extension to this patch that we tested on x86 machines, is to disable PRE
for scalar integer registers, via SMALL_REGISTER_CLASSES. I changed
SMALL_REGISTER_CLASSES into a target hook for this purpose, see [2]. You could
play with this, see if you can use this to cure your problem...
[1] http://gcc.gnu.org/ml/gcc-patches/2008-12/msg00199.html
[2] http://gcc.gnu.org/ml/gcc-patches/2008-12/msg00590.html
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38785