This is the mail archive of the
gcc-bugs@gcc.gnu.org
mailing list for the GCC project.
[Bug target/50829] avx extra copy for _mm256_insertf128_pd
- From: "hjl.tools at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Sat, 01 Dec 2012 20:26:32 +0000
- Subject: [Bug target/50829] avx extra copy for _mm256_insertf128_pd
- Auto-submitted: auto-generated
- References: <bug-50829-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50829
H.J. Lu <hjl.tools at gmail dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |areg.melikadamyan at gmail
| |dot com, hjl.tools at gmail
| |dot com
--- Comment #11 from H.J. Lu <hjl.tools at gmail dot com> 2012-12-01 20:26:32 UTC ---
(In reply to comment #10)
> Created attachment 28846 [details]
> Use subreg
>
> Hmm, I don't understand why we use UNSPEC_CAST. I tried the attached patch to
> use a subreg instead. It passed bootstrap+testsuite and generates optimal code
> for the testcase of this PR.
>
> So, any idea what advantage the unspec has over a subreg? And if none, what is
> the best way to use a subreg?
subreg didn't work before.