https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57952
mmokrejs at gmail dot com changed:
What|Removed |Added
CC||mmokrejs at gmail dot com
---
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57952
--- Comment #3 from mmokrejs at gmail dot com ---
Weird, why g++ can do the task although probably less efficiently than icc?
$ g++ -O3 -march=core-avx-i -mtune=core-avx-i -mavx2 stream.c ; objdump -d
a.out | grep ymm
stream.c:106:48: warning: d
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57952
Jakub Jelinek changed:
What|Removed |Added
CC||jakub at gcc dot gnu.org
--- Comment #4
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57952
--- Comment #5 from mmokrejs at gmail dot com ---
(In reply to Jakub Jelinek from comment #4)
> As for #c2/#c3, GCC 4.9 is not supported anymore and the dumps are too large
> to find out what exactly you mean by efficient and not efficient, both
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57952
--- Comment #6 from Jakub Jelinek ---
(In reply to mmokrejs from comment #5)
> (In reply to Jakub Jelinek from comment #4)
>
> > As for #c2/#c3, GCC 4.9 is not supported anymore and the dumps are too large
> > to find out what exactly you mean b
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57952
--- Comment #7 from mmokrejs at gmail dot com ---
(In reply to Jakub Jelinek from comment #6)
> > $ gcc -O3 -march=native stream.c ; objdump -d a.out | grep ymm | wc -l
> > 63
> > $
>
> Of course, vectorization is only enabled by default for -O3
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57952
--- Comment #8 from Jakub Jelinek ---
Why should there be any references to that? -march= is an ISA selection
option, it says the compiler may use the instructions from the ISA.
-ftree-vectorize is an optimization option (default at -O3 and -Ofa
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57952
--- Comment #9 from mmokrejs at gmail dot com ---
Thank you, I updated https://wiki.gentoo.org/wiki/GCC_optimization and added
the notes on -ftree-vectorize option.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57952
Richard Biener changed:
What|Removed |Added
Known to work||10.1.0
Resolution|---
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57952
--- Comment #1 from vincenzo Innocente ---
I modified a bit the benchmark adding timing
and the new version now vectorize YMM with avx2, still not with old avx
if I remove the call to rdtsc(); it does not use YMM anymore
-fno-tree-pre does not hel
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