[Bug other/38768] -fschedule-insns documentation is wrong for x86 and some other targets

["rguenther at suse dot de" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #7 from rguenther at suse dot de  2010-01-15 09:46 -------
Subject: Re:  -fschedule-insns documentation is wrong for
 x86 and some other targets

On Thu, 14 Jan 2010, reza dot yazdani at amd dot com wrote:

> ------- Comment #5 from reza dot yazdani at amd dot com  2010-01-14 22:12 -------
> > Confirmed.  Also note -fschedule-insns is basically broken for x86 anyways.
> > 
> 
> Do you have a list of bug reports where -fschedule-insns is broken on x86?
> We tried to compile all the SPEC 2006 with this option and there are no
> errors in there.

24319, 38403, 42295, etc.  (that's from a -fschedule-insns search)
or walk through 
http://gcc.gnu.org/bugzilla/buglist.cgi?query_format=advanced&short_desc_type=allwordssubstr&short_desc=&known_to_fail_type=allwordssubstr&known_to_work_type=allwordssubstr&long_desc_type=substring&long_desc=unable+to+find+a+register+to+spill&bug_file_loc_type=allwordssubstr&bug_file_loc=&gcchost_type=allwordssubstr&gcchost=&gcctarget_type=allwordssubstr&gcctarget=&gccbuild_type=allwordssubstr&gccbuild=&keywords_type=allwords&keywords=&bug_status=UNCONFIRMED&bug_status=NEW&bug_status=ASSIGNED&bug_status=SUSPENDED&bug_status=WAITING&bug_status=REOPENED&emailassigned_to1=1&emailtype1=substring&email1=&emailassigned_to2=1&emailreporter2=1&emailcc2=1&emailtype2=substring&email2=&bugidtype=include&bug_id=&votes=&chfieldfrom=&chfieldto=Now&chfieldvalue=&cmdtype=doit&order=Reuse+same+sort+as+last+time&field0-0-0=noop&type0-0-0=noop&value0-0-0=

basically the issue is increasing register pressure and failure to
do register allocation after that.  In 4.5 -fsched-pressure might
fix some of them.

Richard.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38768