[Bug middle-end/47298] -O3 destroys beautifully vectorized code obtained at -O2

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47298 Richard Biener rguenth at gcc dot gnu.org changed: What|Removed |Added Status|NEW

[Bug middle-end/47298] -O3 destroys beautifully vectorized code obtained at -O2

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47298 Eric Botcazou ebotcazou at gcc dot gnu.org changed: What|Removed |Added CC||ebotcazou at

[Bug middle-end/47298] -O3 destroys beautifully vectorized code obtained at -O2

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47298 --- Comment #7 from Richard Guenther rguenth at gcc dot gnu.org 2012-07-05 08:38:05 UTC --- It's a pass ordering issue, cunrolli also can tremendously help vectorization because it enables vectorization of the loop that is then the innermost loop

[Bug middle-end/47298] -O3 destroys beautifully vectorized code obtained at -O2

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47298 --- Comment #8 from Eric Botcazou ebotcazou at gcc dot gnu.org 2012-07-05 08:48:24 UTC --- It's a pass ordering issue, cunrolli also can tremendously help vectorization because it enables vectorization of the loop that is then the innermost

[Bug middle-end/47298] -O3 destroys beautifully vectorized code obtained at -O2

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47298 --- Comment #9 from Richard Guenther rguenth at gcc dot gnu.org 2012-07-05 10:10:28 UTC --- I have a few patches that try to estimate CSE opportunities exposed by complete unrolling. In this case the CSE opportunity is the reduction into C(i,j)

[Bug middle-end/47298] -O3 destroys beautifully vectorized code obtained at -O2

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47298 --- Comment #10 from Richard Guenther rguenth at gcc dot gnu.org 2012-07-05 10:11:55 UTC --- Oh, and you can disable cunrolli already via -fdisable-tree-cunrolli.

[Bug middle-end/47298] -O3 destroys beautifully vectorized code obtained at -O2

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47298 --- Comment #11 from Eric Botcazou ebotcazou at gcc dot gnu.org 2012-07-05 10:30:09 UTC --- Oh, and you can disable cunrolli already via -fdisable-tree-cunrolli. Indeed, I always forget that we have it in 4.7 and above.

[Bug middle-end/47298] -O3 destroys beautifully vectorized code obtained at -O2

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47298 Joost VandeVondele Joost.VandeVondele at mat dot ethz.ch changed: What|Removed |Added Last reconfirmed|

[Bug middle-end/47298] -O3 destroys beautifully vectorized code obtained at -O2

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47298 Richard Guenther rguenth at gcc dot gnu.org changed: What|Removed |Added Status|UNCONFIRMED |NEW

[Bug middle-end/47298] -O3 destroys beautifully vectorized code obtained at -O2

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47298 --- Comment #1 from Richard Guenther rguenth at gcc dot gnu.org 2011-01-14 20:43:15 UTC --- It's faster for me with -O3 (Athlon64, using -march=native).

[Bug middle-end/47298] -O3 destroys beautifully vectorized code obtained at -O2

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47298 --- Comment #2 from Joost VandeVondele Joost.VandeVondele at pci dot uzh.ch 2011-01-14 20:52:54 UTC --- (In reply to comment #1) It's faster for me with -O3 (Athlon64, using -march=native). well not on model name : Intel(R) Xeon(R) CPU

[Bug middle-end/47298] -O3 destroys beautifully vectorized code obtained at -O2

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47298 --- Comment #3 from Joost VandeVondele Joost.VandeVondele at pci dot uzh.ch 2011-01-14 21:02:04 UTC --- Actually, also on AMD I have at -O2 9.4s -O3 11.8s model : 9 model name : AMD Opteron(tm) Processor 6176 SE stepping: