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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/65832] Inefficient vector construction
Date: Fri, 22 May 2015 12:15:00 -0000	[thread overview]
Message-ID: <bug-65832-4-1TD9QD0yYp@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-65832-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65832

--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
On a related note, store_constructor handles VECTOR_TYPE constructors through
the vec_init optab but that doesn't work for vector elements:

            /* Don't use vec_init<mode> if some elements have VECTOR_TYPE.  */
            if (icode != CODE_FOR_nothing)
              {
                tree value;

                FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, value)
                  if (TREE_CODE (TREE_TYPE (value)) == VECTOR_TYPE)
                    {
                      icode = CODE_FOR_nothing;

instead it could, for say a V16QI constructor of four V4QI elements pun
the elements to SI mode, create a V4SI mode vector via vec_init and then
pun it to V16QI.  All punning via subregs.

The vectorizer currently creates such vector constructors from grouped strided
load/store support.


  parent reply	other threads:[~2015-05-22 12:15 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-04-21 13:56 [Bug target/65832] New: " rguenth at gcc dot gnu.org
2015-04-21 14:03 ` [Bug target/65832] " rguenth at gcc dot gnu.org
2015-04-21 14:11 ` rguenth at gcc dot gnu.org
2015-04-28  8:51 ` rguenth at gcc dot gnu.org
2015-04-28  8:55 ` rguenth at gcc dot gnu.org
2015-05-22 12:15 ` rguenth at gcc dot gnu.org [this message]
2015-06-01 10:30 ` rguenth at gcc dot gnu.org
2020-06-24 20:45 ` [Bug middle-end/65832] " gabravier at gmail dot com

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