This is the mail archive of the
gcc-bugs@gcc.gnu.org
mailing list for the GCC project.
[Bug tree-optimization/39839] [4.3/4.4/4.5 regression] loop invariant motion causes stack spill
- From: "vmakarov at redhat dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 22 Apr 2009 20:37:11 -0000
- Subject: [Bug tree-optimization/39839] [4.3/4.4/4.5 regression] loop invariant motion causes stack spill
- References: <bug-39839-17592@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #3 from vmakarov at redhat dot com 2009-04-22 20:37 -------
Actually YARA did not have a rematerialization as IRA. Reload has a primitive
rematerialization of constant values.
Although about 5 years I did implemented a register pressure relief through
rematerialization which is close to Simpson's thesis. It was reported on the
2nd GCC summit. I had a mixed feeling about this: wrong register pressure
calculation (because we have not cover classes at that time), small improvement
but a few additional percents to compilation time.
Probably it is time to return to this and make it optional or default which
will eat a chunk of your recent 5% compilation time improvement :) I'll try to
include this in my plans.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39839