This is the mail archive of the
gcc-bugs@gcc.gnu.org
mailing list for the GCC project.
[Bug lto/45810] 40% slowdown when using LTO for a single-file program
- From: "rguenth at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Mon, 24 Jan 2011 14:07:26 +0000
- Subject: [Bug lto/45810] 40% slowdown when using LTO for a single-file program
- Auto-submitted: auto-generated
- References: <bug-45810-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45810
--- Comment #22 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-01-24 14:07:14 UTC ---
(In reply to comment #15)
> Enabling early FRE
> Index: passes.c
> ===================================================================
> --- passes.c (revision 169136)
> +++ passes.c (working copy)
> @@ -760,6 +760,7 @@
> NEXT_PASS (pass_remove_cgraph_callee_edges);
> NEXT_PASS (pass_rename_ssa_copies);
> NEXT_PASS (pass_ccp);
> + NEXT_PASS (pass_fre);
> NEXT_PASS (pass_forwprop);
> /* pass_build_ealias is a dummy pass that ensures that we
> execute TODO_rebuild_alias at this point. Re-building
> @@ -782,7 +783,7 @@
>
> reduces perida size estimate to 694 (so by about 30%) and hookes law to 141 (by
> 11%). Not enough to make inlining happen, still.
That FRE pass should be after pass_sra_early (certainly after
pass_build_ealias).