This is the mail archive of the
gcc-bugs@gcc.gnu.org
mailing list for the GCC project.
[Bug tree-optimization/17863] [4.0/4.1/4.2/4.3 Regression] performance loss (not inlining as much??)
- From: "hubicka at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 30 Jan 2008 18:14:53 -0000
- Subject: [Bug tree-optimization/17863] [4.0/4.1/4.2/4.3 Regression] performance loss (not inlining as much??)
- References: <bug-17863-2109@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #36 from hubicka at gcc dot gnu dot org 2008-01-30 18:14 -------
Looking at the .optimized dump, one obvious problem is that we keep a lot of
pointer arithmetic that should be forward propagated:
<L147>:;
D.184420 = *pz;
p1 = pz + 8;
D.184422 = *p1;
p1 = p1 + 8;
D.184424 = *p1;
p1 = p1 + 8;
D.184426 = *p1;
p1 = p1 + 8;
D.184428 = *p1;
p1 = p1 + 8;
D.184430 = *p1;
p1 = p1 + 8;
D.184432 = *p1;
D.184434 = *(p1 + 8);
Those seems to be all just array manipulations.
Honza
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17863