[Bug target/34501] The vector cost model does not seem suited for Intel Core2Duo

dominiq at lps dot ens.fr gcc-bugzilla@gcc.gnu.org
Tue Dec 6 11:46:00 GMT 2011


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34501

Dominique d'Humieres <dominiq at lps dot ens.fr> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED

--- Comment #6 from Dominique d'Humieres <dominiq at lps dot ens.fr> 2011-12-06 11:45:39 UTC ---
Although I don't know if the cost model is perfectly tuned for the Intel
Core2Duo, the particular instance of this PR has been fixed since a long time
(see pr34265 and pr50904), on trunk at r182043, I now get on a slightly faster
proc (2.5Ghz vs. 2.1Ghz):

[macbook] lin/test% time gfc -O3 -ffast-math -funroll-loops induct.f90
7.969u 0.101s 0:08.07 99.8%    0+0k 0+40io 0pf+0w
[macbook] lin/test% time a.out > /dev/null
13.062u 0.026s 0:13.09 99.9%    0+0k 0+0io 0pf+0w
[macbook] lin/test% time gfc -O3 -ffast-math -funroll-loops induct.f90 --param
min-vect-loop-bound=2
7.965u 0.110s 0:08.08 99.8%    0+0k 0+23io 0pf+0w
[macbook] lin/test% time a.out > /dev/null
13.063u 0.027s 0:13.09 99.9%    0+0k 0+0io 0pf+0w

So I am closing the PR as fixed. Thanks for all the work leading to a nice
speed-up.



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