[Bug rtl-optimization/24319] [4.3/4.4/4.5 regression] amd64 register spill error with -fschedule-insns

[vmakarov at redhat dot com]

------- Comment #21 from vmakarov at redhat dot com  2009-09-02 17:11 -------
I see.  I though you compared '-fschedule-insns' and '-fschedule-insns
-fsched-pressure'.

Your numbers shows the same as I reported for SPEC2000.  The -fsched-pressure
adds upto 3% compiler time (for power6) on x86 and x86_64 it is practically the
same time (although -fsched-pressure does more job, it is compensated by
smaller # of insns after RA).

I did not analyzed your code but I think your code is quite specific and
probably has a lot of parallelism which creates long ready and queue list.  You
could play with param max-pending-list-length to see will it help.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24319