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From: "ramana at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/65375] aarch64: poor codegen for vld2q_f32 and vst2q_f32
Date: Wed, 24 Jun 2015 09:06:00 -0000	[thread overview]
Message-ID: <bug-65375-4-N0KegA5sHg@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-65375-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65375

--- Comment #11 from Ramana Radhakrishnan <ramana at gcc dot gnu.org> ---
(In reply to Jim Wilson from comment #10)
> Improved, but not completely resolved.  We still get unnecessary orr
> instructions, same as in comment 2.  This is partly an issue with the
> register allocator not handling partially overlapping register reads/writes
> very well.  We already have a few other bugs for that.  This is also partly
> an issue with how the aarch64 builtins work, via
> __builtin_aarch64_[gs]et_qregoiv4sf which create the partially overlapping
> register reads/writes.  The ARM builtins don't work this way, they use a
> union for type punning, and hence don't have the same problem.

Both the ARM and the AArch64 ports have the issues with partially overlapping
register reads / writes especially with the vzip / vuzip style intrinsics in
AArch32 world or even the larger vld3/4 intrinsics in both ARM and AArch64
states. It would be nice to fix that finally.

If that is the only issue left in the ticket - maybe we should just park this
example in that ticket - IIRC PR43725 and close this one out ?

regards
Ramana


  parent reply	other threads:[~2015-06-24  9:06 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-03-10  8:15 [Bug target/65375] New: poor codegen for ld[234]/st[234] kugan at gcc dot gnu.org
2015-03-10  8:16 ` [Bug target/65375] " kugan at gcc dot gnu.org
2015-03-10  8:18 ` kugan at gcc dot gnu.org
2015-03-10  8:19 ` kugan at gcc dot gnu.org
2015-03-10  8:32 ` pinskia at gcc dot gnu.org
2015-04-13 16:36 ` [Bug target/65375] aarch64: poor codegen for vld2q_f32 and vst2q_f32 mkuvyrkov at gcc dot gnu.org
2015-04-14  8:05 ` jgreenhalgh at gcc dot gnu.org
2015-04-14  8:06 ` mkuvyrkov at gcc dot gnu.org
2015-04-14  9:11 ` kugan at gcc dot gnu.org
2015-06-23 15:40 ` wilson at gcc dot gnu.org
2015-06-24  9:06 ` ramana at gcc dot gnu.org [this message]
2015-06-24  9:13 ` kugan at gcc dot gnu.org
2015-06-25 20:49 ` ramana at gcc dot gnu.org

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