[Bug target/31850] gcc.c-torture/compile/limits-fnargs.c is slow at compiling for spu-elf

tehila at il dot ibm dot com gcc-bugzilla@gcc.gnu.org
Tue Nov 18 07:37:00 GMT 2008



------- 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



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