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From: "rearnsha at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug testsuite/54622] gcc.dg/vect test failures for arm big-endian
Date: Wed, 19 Sep 2012 22:27:00 -0000	[thread overview]
Message-ID: <bug-54622-4-yu7LbGtrEJ@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-54622-4@http.gcc.gnu.org/bugzilla/>


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54622

--- Comment #4 from Richard Earnshaw <rearnsha at gcc dot gnu.org> 2012-09-19 22:26:49 UTC ---
The reasons for the vector problems in big-endian largely fall into two areas:

1) Neon vector elements are numbered from the LSB of the vector register in
both big and little-endian modes.  GCC assumes that vector elements in
big-endian are numbered from the MSB.  This means compensation code is needed
when elements are addressed directly (for example shuffle operations).

2) Quad-words in 256-bit vectors are not pure big-endian, the DWords are
swapped in order on loads.  GCC can't currently cope with this in any sensible
manner.


  parent reply	other threads:[~2012-09-19 22:27 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-09-19  0:54 [Bug testsuite/54622] New: " janis at gcc dot gnu.org
2012-09-19  1:09 ` [Bug testsuite/54622] " pinskia at gcc dot gnu.org
2012-09-19  1:18 ` janis at gcc dot gnu.org
2012-09-19  1:29 ` pinskia at gcc dot gnu.org
2012-09-19 22:27 ` rearnsha at gcc dot gnu.org [this message]
2012-09-26 16:25 ` jules at gcc dot gnu.org
2012-09-26 16:46 ` janis at gcc dot gnu.org
2012-09-26 21:52 ` janis at gcc dot gnu.org
2013-01-16 18:50 ` janis at gcc dot gnu.org
2013-03-20  0:45 ` pinskia at gcc dot gnu.org

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