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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/95839] Failure to optimize addition of vector elements to vector addition
Date: Wed, 24 Jun 2020 16:05:04 +0000 [thread overview]
Message-ID: <bug-95839-4-4oh1f2h7LG@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-95839-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95839
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |marxin at gcc dot gnu.org
--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #1)
> GCC does not yet vectorize stmts without loads (and explicitely rejects
> vector types somewhere).
But this particular case might be easy since we already vectorize from CTORs,
we likely just disregard the BB because it doesn't contain any datarefs:
_1 = BIT_FIELD_REF <a_7(D), 32, 0>;
_2 = BIT_FIELD_REF <b_8(D), 32, 0>;
_3 = _1 + _2;
_4 = BIT_FIELD_REF <a_7(D), 32, 32>;
_5 = BIT_FIELD_REF <b_8(D), 32, 32>;
_6 = _4 + _5;
_9 = {_3, _6};
vectorization might turn this into
_10 = {_1, _4 };
_11 = {_2, _5 };
_9 = _10 + _11;
and then forwprop CTOR "folding" will get rid of the
_10 and _11 CTORs (until the vectorizer handles BIT_FIELD_REFs
of existing vectors).
So kind-of "easy hack" - Martin, your branch might already do this
(not give up on <= 1 datarefs).
next prev parent reply other threads:[~2020-06-24 16:05 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-23 12:26 [Bug tree-optimization/95839] New: " gabravier at gmail dot com
2020-06-23 14:26 ` [Bug tree-optimization/95839] " rguenth at gcc dot gnu.org
2020-06-24 15:00 ` ubizjak at gmail dot com
2020-06-24 16:05 ` rguenth at gcc dot gnu.org [this message]
2020-06-24 16:10 ` rguenth at gcc dot gnu.org
2020-06-25 10:52 ` rguenth at gcc dot gnu.org
2020-06-25 13:56 ` cvs-commit at gcc dot gnu.org
2020-06-25 14:54 ` rguenth at gcc dot gnu.org
2020-07-01 11:32 ` cvs-commit at gcc dot gnu.org
2020-07-01 11:34 ` rguenth at gcc dot gnu.org
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