This is the mail archive of the
gcc-bugs@gcc.gnu.org
mailing list for the GCC project.
[Bug tree-optimization/54525] Recognize (vec_)cond_expr in mask operation
- From: "glisse at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Sat, 15 Sep 2012 08:28:08 +0000
- Subject: [Bug tree-optimization/54525] Recognize (vec_)cond_expr in mask operation
- Auto-submitted: auto-generated
- References: <bug-54525-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54525
--- Comment #1 from Marc Glisse <glisse at gcc dot gnu.org> 2012-09-15 08:28:08 UTC ---
(In reply to comment #0)
> vpcmpgtq %xmm2, %xmm3, %xmm2
> vpcmpeqd %xmm3, %xmm3, %xmm3
[...]
> (also notice that for some reason all comparisons (I tried < <= > >= and even
> with a ~ in front) generate a combination of gt and eq, never just gt)
Hmm, that remark was nonsense, the eq has nothing to do with the gt, it is just
the way the compiler generates a constant -1 vector so it can then xor with it
to compute a ~.