From: Mark Mitchell <mark@codesourcery.com>
To: Richard Kenner <kenner@vlsi1.ultra.nyu.edu>
Cc: gcc-patches@gcc.gnu.org
Subject: Re: Patch to allow Ada to work with tree-ssa
Date: Tue, 22 Jun 2004 18:45:00 -0000 [thread overview]
Message-ID: <40D86AA1.6010000@codesourcery.com> (raw)
In-Reply-To: <10406221706.AA07120@vlsi1.ultra.nyu.edu>
Richard Kenner wrote:
> In particular, you've just added an extra entry to ARRAY_REF and
> COMPONENT_REF, making these two common tree nodes bigger.
> (COMPONENT_REF, in particular, is used extensively in C++; every
> access to a class member variable is a COMPONENT_REF.) These extra
> entries are unnecessary in C and C++, meaning that for GCC's two
> most-used languages you've just increased memory usage with no
> benefit. If you need some additional stuff for Ada, please find a way
> that doesn't penalize C and C++.
>
>Here's the specific test case for C. I note that it isn't valid C++,
>but I don't know C++ well enough to make a similar case there. Note
>that the proposal involving using an INDIRECT_REF won't work with this
>case because it's a bitfield.
>
>int
>sub1 (int n)
>{
> struct foo {int arr[n]; int filler : 3; int fld : 4;} x;
>
> return x.fld;
>}
>
>
I believe that there are tests cases in GNU C that require the
functionality you've added.
However, you've penalized the vastly more common case (100% of the cases
in ANSI/ISO C89) at the expense of an uncommon case.
That's why you should find another way -- a different tree code, a flag
in the node indicating how many arguments are in use, or stuff the
additional arguments into the existing slots by using a TREE_LIST in
those slots as necessary.
--
Mark Mitchell
CodeSourcery, LLC
(916) 791-8304
mark@codesourcery.com
next prev parent reply other threads:[~2004-06-22 17:21 UTC|newest]
Thread overview: 77+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-06-22 18:19 Richard Kenner
2004-06-22 18:36 ` Nathan Sidwell
2004-06-22 18:37 ` Nathan Sidwell
2004-06-22 18:45 ` Mark Mitchell [this message]
-- strict thread matches above, loose matches on Subject: below --
2004-07-29 19:02 Richard Kenner
2004-07-29 18:43 Richard Kenner
2004-07-29 17:12 Richard Kenner
2004-07-29 17:13 ` Diego Novillo
2004-07-29 17:57 ` Richard Henderson
2004-06-25 15:28 Richard Kenner
2004-06-28 15:09 ` Paolo Bonzini
2004-06-24 15:58 Richard Kenner
2004-06-24 16:04 ` Nathan Sidwell
2004-06-25 14:43 ` Joseph S. Myers
2004-06-23 5:54 Richard Kenner
2004-06-23 2:32 Richard Kenner
2004-06-23 4:54 ` Bryce McKinlay
2004-06-23 0:16 Richard Kenner
2004-06-22 23:05 Richard Kenner
2004-06-23 11:42 ` Nathan Sidwell
2004-06-22 22:18 Richard Kenner
2004-06-23 1:07 ` Richard Henderson
2004-06-22 21:30 Richard Kenner
2004-06-22 22:04 ` Paul Brook
2004-06-22 21:27 Richard Kenner
2004-06-22 21:29 ` Mark Mitchell
2004-06-22 21:10 Richard Kenner
2004-06-22 21:12 ` Mark Mitchell
2004-06-22 22:16 ` Daniel Berlin
2004-06-22 21:07 Richard Kenner
2004-06-22 21:12 ` Bryce McKinlay
2004-06-22 21:05 Richard Kenner
2004-06-22 21:01 Richard Kenner
2004-06-22 20:54 Richard Kenner
2004-06-22 21:06 ` Paul Brook
2004-06-22 21:37 ` Richard Henderson
2004-06-22 20:44 Richard Kenner
2004-06-22 21:03 ` Mark Mitchell
2004-06-23 20:58 ` Geoffrey Keating
2004-06-22 20:40 Richard Kenner
2004-06-22 22:02 ` Nathan Sidwell
2004-06-22 22:27 ` Joseph S. Myers
2004-06-22 20:23 Richard Kenner
2004-06-22 20:37 ` Joseph S. Myers
2004-06-23 20:47 ` Geoffrey Keating
2004-06-24 14:59 ` Joseph S. Myers
2004-06-24 16:26 ` Richard Earnshaw
2004-06-24 19:57 ` Laurent GUERBY
2004-06-24 20:06 ` Diego Novillo
2004-06-24 20:24 ` Andrew Pinski
2004-06-24 22:35 ` Laurent GUERBY
2004-06-24 21:33 ` Laurent GUERBY
2004-06-24 21:01 ` Joseph S. Myers
2004-06-25 14:51 ` Richard Earnshaw
2004-06-22 20:22 Richard Kenner
2004-06-22 20:30 ` Mark Mitchell
2004-06-22 19:05 Richard Kenner
2004-06-22 20:10 ` Joseph S. Myers
2004-06-22 20:27 ` Andrew Haley
[not found] <10406221359.AA05860@vlsi1.ultra.nyu.edu>
2004-06-22 18:47 ` Richard Henderson
2004-06-22 18:33 Richard Kenner
2004-06-22 17:05 Richard Kenner
2004-06-22 17:21 ` Andrew Haley
2004-06-22 19:01 ` Richard Henderson
2004-06-22 16:34 Richard Kenner
2004-06-22 16:33 Richard Kenner
2004-06-22 17:46 ` Mark Mitchell
2004-06-22 18:17 ` Joseph S. Myers
2004-06-22 18:52 ` Richard Henderson
2004-06-22 19:37 ` Zack Weinberg
2004-06-22 7:05 Richard Kenner
2004-06-22 7:29 ` Mark Mitchell
2004-06-22 9:14 ` Andrew Pinski
2004-06-22 14:16 ` Andrew Haley
2004-06-22 11:00 ` Richard Henderson
2004-06-22 13:52 ` Ranjit Mathew
2004-07-29 17:02 ` Diego Novillo
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