http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49485
--- Comment #7 from Jakub Jelinek jakub at gcc dot gnu.org 2011-10-20
07:36:40 UTC ---
For me the trunk with vectorization is certainly faster than 4.3, it is true
that 4.6 is slower.
4.3 -O3 -ffast-math 0m0.144s
4.3 -O3 -ffast-math
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49485
--- Comment #8 from Jakub Jelinek jakub at gcc dot gnu.org 2011-10-20
07:57:10 UTC ---
BTW, 4.6 numbers can be improved to the trunk numbers by applying
http://gcc.gnu.org/viewcvs?root=gccview=revrev=179460
(aka a subset of Eric's r179165 change)
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49485
--- Comment #9 from Paolo Carlini paolo.carlini at oracle dot com 2011-10-20
08:19:28 UTC ---
Ah great. Then I wonder if at this point we couldn't even resolve this..
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49485
--- Comment #10 from Jakub Jelinek jakub at gcc dot gnu.org 2011-10-20
08:42:55 UTC ---
Certainly not right now, this isn't a kind of change that should be added in
between 4.6.2-RC and 4.6.2. Maybe later.
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49485
Andrew Pinski pinskia at gcc dot gnu.org changed:
What|Removed |Added
Keywords|
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49485
--- Comment #5 from Andrew Pinski pinskia at gcc dot gnu.org 2011-10-20
01:09:02 UTC ---
apinski@apinskidesktop:~$ g++ t.cc -O3 -ffast-math
apinski@apinskidesktop:~$ ./a.out
apinski@apinskidesktop:~$ time ./a.out
real0m0.329s
user
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49485
--- Comment #6 from Andrew Pinski pinskia at gcc dot gnu.org 2011-10-20
01:13:54 UTC ---
Looks like vectorizer is causing the slow down at least for me on the trunk
that is -mno-sse makes the slowdown go away.
