https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83610
Martin Liška <marxin at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |WAITING
Last reconfirmed| |2017-12-29
CC| |marxin at gcc dot gnu.org
Ever confirmed|0 |1
--- Comment #2 from Martin Liška <marxin at gcc dot gnu.org> ---
Thanks for report. I can confirm that it changed in GCC 4.9.0 and newer
versions.
Note that version without branching (using cmove) is actually also conditional
code and is transformed by 'If-conversion pass'.
What you can do is to change default probability of expect (which is by default
90%):
--param builtin-expect-probability=99
Doing that I see original version w/o cmove. Is it helpful for you?
Do you have a microbenchmark you can attach that compares speed of both
versions?
