From: Scott Wood <scottwood@freescale.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] use of C99
Date: Wed, 08 Apr 2009 17:26:10 -0500 [thread overview]
Message-ID: <49DD2482.7040909@freescale.com> (raw)
In-Reply-To: <49DD10BF.80002@freescale.com>
Timur Tabi wrote:
> Scott Wood wrote:
>
>> It frees the variable up for later such blocks to use. As does
>> declaring iterators inside a for loop, but I guess that's forbidden as
>> well. :-)
>
> I'm not sure whether we want to allow the same variable to be defined
> more than once, even with the same type, inside a function.
What's wrong with this:?
for (i = 0; i < n; i++) {
int j;
...
}
for (i = 0; i < m; i++) {
int j;
...
}
>> Chances are it will allocate all stack space for all variables up front,
>> regardless of where they're declared.
>
> Yes, but it many cases it won't allocate any stack space at all because
> it will just keep the variable in a register. My point was that if a
> variable is defined later in a function, then it's more likely to have
> limited scope, so the compiler will be more likely to use a register
> instead of stack to store it.
I don't think it will make a difference. The compiler knows what the
lifetime of the variable is, regardless of where you declare it.
-Scott
next prev parent reply other threads:[~2009-04-08 22:26 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-04-08 18:51 [U-Boot] use of C99 Kumar Gala
2009-04-08 19:28 ` Wolfgang Denk
2009-04-08 19:46 ` Jerry Van Baren
2009-04-08 20:25 ` Timur Tabi
2009-04-08 20:46 ` Premi, Sanjeev
2009-04-08 20:57 ` Timur Tabi
2009-04-08 21:26 ` Premi, Sanjeev
2009-04-08 21:34 ` Timur Tabi
2009-04-08 21:03 ` Ben Warren
2009-04-08 21:23 ` Premi, Sanjeev
2009-04-08 20:52 ` Scott Wood
2009-04-08 21:01 ` Timur Tabi
2009-04-08 22:26 ` Scott Wood [this message]
2009-04-08 21:34 ` Wolfgang Denk
2009-04-08 21:38 ` Timur Tabi
2009-04-08 22:39 ` Graeme Russ
2009-04-08 22:45 ` Timur Tabi
2009-04-08 22:59 ` Wolfgang Denk
2009-04-08 23:09 ` Scott Wood
2009-04-08 22:28 ` Scott Wood
2009-04-08 21:27 ` Wolfgang Denk
2009-04-08 23:22 ` Larry Johnson
2009-04-08 23:40 ` Scott Wood
2009-04-09 4:27 ` Kumar Gala
2009-04-09 11:38 ` Jerry Van Baren
-- strict thread matches above, loose matches on Subject: below --
2009-04-09 1:53 Pink Boy
2009-04-09 2:12 ` Jerry Van Baren
2009-04-09 5:50 ` Wolfgang Denk
2009-04-09 13:27 ` Larry Johnson
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=49DD2482.7040909@freescale.com \
--to=scottwood@freescale.com \
--cc=u-boot@lists.denx.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.