From: Jamie Lokier <egcs@tantalophile.demon.co.uk>
To: Kevin Lawton <kevinlawton2001@yahoo.com>
Cc: Michael Matz <matz@suse.de>, gcc@gcc.gnu.org
Subject: Re: Request of new __attribute__ for switch statements (elimination of the bounds check)
Date: Tue, 15 Oct 2002 15:32:00 -0000 [thread overview]
Message-ID: <20021015213954.GC31811@bjl1.asuk.net> (raw)
In-Reply-To: <20021015201332.21851.qmail@web80311.mail.yahoo.com>
Kevin Lawton wrote:
> The __attibute_ angle is simple, I can exactly tell the
> compiler when I care to have it applied (maybe only one
> case in all the code), and it disappears quickly with
> an #ifdef'd macro. Which makes it play nice with "other"
> compilers.
If your proposal is actually implemented, could it please be changed
so that the attribute goes _inside_ the switch parentheses?
Then it can be used to optimise "variant type" macros without having
to uglify thousands of switch statements in a program (just the macro
definitions). To use a few example from GCC itself, these kind of
can all be optimised in this way:
switch (TREE_CODE (t)) { /* ... */ }
switch (GET_CODE (rtx)) { /* ... */ }
switch (GET_MODE (rtx)) { /* ... */ }
(I'm not sure you'd want to optimise these in GCC because of the risk
of bugs, but there are programs which use similar macros where it is
more desirable to optimise).
-- Jamie
next prev parent reply other threads:[~2002-10-15 21:37 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-10-11 13:20 Kevin Lawton
2002-10-12 4:18 ` Ralph Loader
2002-10-14 8:31 ` Richard Zidlicky
2002-10-14 10:09 ` Dale Johannesen
2002-10-14 21:11 ` Jamie Lokier
2002-10-14 22:01 ` Zack Weinberg
2002-10-15 8:12 ` Michael Matz
2002-10-15 19:15 ` Zack Weinberg
2002-10-15 19:18 ` Dale Johannesen
2002-10-16 14:07 ` Richard Henderson
2002-10-15 21:16 ` Kevin Lawton
2002-10-15 23:40 ` Tim Hollebeek
2002-10-16 3:40 ` Michael Matz
2002-10-16 13:38 ` Tim Hollebeek
2002-10-16 14:23 ` Michael Matz
2002-10-16 13:27 ` Hartmut Schirmer
2002-10-16 3:25 ` Joseph S. Myers
2002-10-16 7:57 ` Fergus Henderson
2002-10-16 11:19 ` Daniel Jacobowitz
2002-10-15 7:54 ` Michael Matz
2002-10-15 13:29 ` Jamie Lokier
2002-10-15 14:06 ` Kevin Lawton
2002-10-15 15:32 ` Jamie Lokier [this message]
2002-10-15 14:28 ` Michael Matz
2002-10-15 15:19 ` Jamie Lokier
2002-10-11 13:22 Robert Dewar
2002-10-11 15:12 ` Kevin Lawton
2002-10-12 10:43 ` Alexandre Oliva
2002-10-15 6:43 Mattias Engdegård
2002-10-15 22:40 Robert Dewar
2002-10-15 23:57 ` Zack Weinberg
2002-10-16 9:19 Robert Dewar
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