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Date: Mon, 17 Feb 2003 17:04:52 -0800
To: cygwin AT cygwin DOT com
From: Randall R Schulz <rrschulz AT cris DOT com>
Subject: RE:size limit for static arrays in cygwin/gcc
In-Reply-To: <20030217205514.36613.qmail@web21402.mail.yahoo.com>
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Danny,

At 12:55 2003-02-17, Danny Smith wrote:
>Randall R Schulz <rrschulz at cris dot com>  wrote:
>
> > A couple of months ago, someone reported on how local (stack)
> > allocations larger than a certain threshold were allocated on the heap.
> > In fact, you, Danny, contributed materially to that thread: Subject
> > "Strange behaviour of gcc" starting with a posting by
> > fabrizio_ge-wolit AT tiscali DOT it on Dec. 24, 2002.
>
>No that's not quite right:
>
>Stack allocations larger than one page (4KB) cause gcc to probe the stack.
>The allocation is still static

I was clearly confused about what "alloca" does: It allocates space on 
the stack, _not_ on the heap, as I thought.

However, there must be a terminological issue here, because I would 
describe what alloca does as _dynamic_ stack-resident allocation. It is 
dynamic because it happens as a result of a run-time call. I understand 
static to mean an action (allocation, binding, computation, etc.) that 
is handled entirely at compile and / or link time.


>I think, also, the stack probe is automatically called in main, to force
>alignment of stack to a page boundary.
>
>...
>
>Danny


Randall Schulz 


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