This is the mail archive of the
gcc-bugs@gcc.gnu.org
mailing list for the GCC project.
[Bug target/56309] conditional moves instead of compare and branch result in almost 2x slower code
- From: "jakub at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Fri, 18 Oct 2013 09:12:13 +0000
- Subject: [Bug target/56309] conditional moves instead of compare and branch result in almost 2x slower code
- Auto-submitted: auto-generated
- References: <bug-56309-4 at http dot gcc dot gnu dot org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56309
--- Comment #29 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
FYI, I've posted patchset to only do tree if-conversion for vectorization and
not for scalar basic blocks (and also for conditional load/store support in
vectorized loops using AVX vmaskmov* and AVX2 masked gathers) in
http://gcc.gnu.org/ml/gcc-patches/2013-10/msg01373.html
I'd appreciate any benchmark results for that.
On the by-ref-O3.ii testcase there is no change, but by-val-O3.ii seems to be
consistently faster, around 20% on AMD 8354 and 35% on Intel 2600.