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From: kenner@vlsi1.ultra.nyu.edu (Richard Kenner)
To: aoliva@redhat.com
Cc: gcc-patches@gcc.gnu.org, gcc@gcc.gnu.org
Subject: Re: DATA_ALIGNMENT vs. DECL_USER_ALIGNMENT
Date: Wed, 23 Apr 2003 02:20:00 -0000	[thread overview]
Message-ID: <10304230111.AA11080@vlsi1.ultra.nyu.edu> (raw)

    The point is that you're saying it could increase the alignment of an
    object in spite of a user-specified alignment for its type.  You can't
    tell whether the alignment was defined for interface, space or
    performance, so a user-specified alignment for a type should be
    obeyed.

As has been discussed, "obeyed" means very different things for types
and objects.  For types, you must not treat the type as being more
aligned.  For objects, a more-aligned object is *also* less aligned, so
aligning an object more than that of its type is "obeying" the alignment
of the type.  And we know there are cases (such as minimum alignment on
S390) where you *must* increase the alignment of an object from that of
its type.

So the question is when to supress the an optional increase for
objects and I claim the only time should be if there is an alignment
specified *for a particular object*.

             reply	other threads:[~2003-04-23  1:07 UTC|newest]

Thread overview: 101+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-04-23  2:20 Richard Kenner [this message]
2003-04-23  5:31 ` Alexandre Oliva
2003-04-24  6:23   ` Jason Merrill
2003-04-24  8:43     ` Geert Bosch
2003-04-24 17:48       ` Jason Merrill
2003-04-24 18:04         ` Zack Weinberg
2003-04-24 19:31           ` Jason Merrill
2003-04-24 21:32         ` Geert Bosch
2003-04-24 23:24           ` Jason Merrill
2003-04-25  2:56     ` Richard Henderson
  -- strict thread matches above, loose matches on Subject: below --
2003-04-23  3:29 Robert Dewar
2003-04-22 15:08 Richard Kenner
2003-04-23  1:07 ` Alexandre Oliva
2003-04-22  0:15 Robert Dewar
2003-04-22  1:58 ` Jamie Lokier
2003-04-22  0:11 Robert Dewar
2003-04-22  1:35 ` Jamie Lokier
2003-04-21 21:25 Richard Kenner
2003-04-21 20:59 Richard Kenner
2003-04-21 21:14 ` Jamie Lokier
2003-04-21 20:45 Richard Kenner
2003-04-21 20:58 ` Jamie Lokier
2003-04-21 18:14 Richard Kenner
2003-04-21 20:33 ` Jamie Lokier
2003-04-21 17:25 Richard Kenner
2003-04-21 18:14 ` Jamie Lokier
2003-04-22  9:00 ` Alexandre Oliva
2003-04-20 21:28 Robert Dewar
2003-04-21 17:05 ` Alexandre Oliva
2003-04-20 21:19 Robert Dewar
2003-04-18 11:41 Richard Kenner
2003-04-18  8:06 Richard Kenner
2003-04-18  8:59 ` Richard Henderson
2003-04-17 21:41 Richard Kenner
2003-04-17 23:20 ` Alexandre Oliva
2003-04-18  1:16 ` Richard Henderson
2003-04-17 21:40 Richard Kenner
2003-04-17 11:56 Richard Kenner
2003-04-17 20:35 ` Alexandre Oliva
2003-04-17 22:41   ` Geert Bosch
2003-04-17 23:19     ` Alexandre Oliva
2003-04-17 10:44 Robert Dewar
2003-04-17 20:30 ` Alexandre Oliva
2003-04-17  8:12 Richard Kenner
2003-04-17  8:38 ` Alexandre Oliva
2003-04-11 22:26 Robert Dewar
2003-04-11 16:59 Robert Dewar
2003-04-11 18:49 ` Laurent Guerby
2003-04-11 16:51 Robert Dewar
2003-04-11 14:52 Robert Dewar
2003-04-11  4:45 Richard Kenner
2003-04-17  5:39 ` Alexandre Oliva
2003-04-11  0:45 Ulrich Weigand
2003-04-10 22:43 Richard Kenner
2003-04-11  0:31 ` Richard Henderson
2003-04-11  2:19   ` David Edelsohn
2003-04-10 22:23 Richard Kenner
2003-04-10 22:16 Richard Kenner
2003-04-10 22:07 Richard Kenner
2003-04-10 22:23 ` David Edelsohn
2003-04-10 22:05 Robert Dewar
2003-04-10 22:02 Richard Kenner
2003-04-10 22:24 ` Richard Henderson
2003-04-11 11:20   ` Laurent Guerby
2003-04-11 11:57     ` Arnaud Charlet
2003-04-11 14:16       ` Laurent Guerby
2003-04-10 21:56 Richard Kenner
2003-04-10 22:02 ` David Edelsohn
2003-04-10 21:45 Richard Kenner
2003-04-10 21:52 ` David Edelsohn
2003-04-10 21:57 ` Richard Henderson
2003-04-10 21:44 Richard Kenner
2003-04-10 21:32 Robert Dewar
2003-04-10 21:32 ` David Edelsohn
2003-04-10 21:31 Richard Kenner
2003-04-10 21:29 Robert Dewar
2003-04-10 21:10 Richard Kenner
2003-04-10 21:10 Robert Dewar
2003-04-10 21:17 ` David Edelsohn
2003-04-10 21:04 Richard Kenner
2003-04-10 21:41 ` Geoff Keating
2003-04-10 20:57 Robert Dewar
2003-04-10 21:07 ` Ulrich Weigand
2003-04-10 20:52 Robert Dewar
2003-04-10 20:39 Richard Kenner
2003-04-10 21:00 ` Geoff Keating
2003-04-10 21:01 ` Ulrich Weigand
2003-04-10 21:44 ` Richard Henderson
2003-04-10 20:13 Richard Kenner
2003-04-10 20:28 ` Ulrich Weigand
2003-04-10 19:20 Richard Kenner
2003-04-10  5:33 Richard Kenner
2003-04-10  7:20 ` Ulrich Weigand
2003-04-09 23:31 Ulrich Weigand
2003-04-10  2:27 ` Richard Henderson
2003-04-10  3:10   ` Ulrich Weigand
2003-04-10 16:20     ` Ulrich Weigand
2003-04-10 16:39       ` Geoff Keating
2003-04-10 16:44         ` Ulrich Weigand
2003-04-10 18:06       ` Richard Henderson
2003-04-08 17:47 Ulrich Weigand

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