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[Bug target/78102] [5/6/7 regression] GCC refuses to generate PCMPEQQ instruction for SSE4.1
- From: "ubizjak at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Tue, 25 Oct 2016 09:21:17 +0000
- Subject: [Bug target/78102] [5/6/7 regression] GCC refuses to generate PCMPEQQ instruction for SSE4.1
- Auto-submitted: auto-generated
- References: <bug-78102-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78102
--- Comment #12 from Uroš Bizjak <ubizjak at gmail dot com> ---
(In reply to Richard Biener from comment #11)
> A separate optab for equality compares would maybe work (if the difference
> between 4.1 and 4.2 is really equality vs. relational compares).
> vcond_eq (handling both signed/unsigned obviously).
Yes, as shown in [1] the difference is only in the availability of PCMPGTQ [SSE
4.2] besides PCMPEQQ [SSE4.1]. This is all we have for DImode...
[1] https://en.wikipedia.org/wiki/SSE4#SSE4.1