------- Comment #9 from tehila at il dot ibm dot com 2008-11-18 07:35 -------
This testcase is indeed very slow on SPU, with -O2 and above.
I don't see any slowness for -O1.
If I turn off the insns scheduler (with -fno-schedule-insns) it is much faster:
X4 faster for 1,000 args (ARG3), much more for 10,000 args (ARG4).
It seems that the scheduler generates excessive register pressure, by hoisting
loads and sinking stores.
Maybe the "decision-maker" of the scheduler (which insn to move) should be
improved.
--
tehila at il dot ibm dot com changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |uweigand at de dot ibm dot
| |com, bergner at vnet dot ibm
| |dot com, abel at ispras dot
| |ru, tehila at il dot ibm dot
| |com, zaks at il dot ibm dot
| |com, meissner at gcc dot gnu
| |dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31850
