Date: Wed, 14 Jan 1998 13:15:56 +0200 (IST)
From: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
To: Marc Lehmann <pcg AT goof DOT com>
cc: djgpp-workers AT delorie DOT com, Andrew Crabtree <andrewc AT rosemail DOT rose DOT hp DOT com>
Subject: Re: stack alignment options
In-Reply-To: <19980112231700.01629@cerebro.laendle>
Message-ID: <Pine.SUN.3.91.980114131452.8730H-100000@is>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Precedence: bulk


On Mon, 12 Jan 1998, Marc Lehmann wrote:

> I was asked to sent an explanation of the options pgcc (and egcs sometime
> in the future) uses to ensure an 8 byte alignment of doubles, how it is
> achieved and what breaks.

Thanks for a detailed explanation.

> also, function like qsort() possibly destroys the alignment
> (although these libc functions are rare).

Can you explain why?  Is this because `qsort' accepts a pointer to a
function as one of its arguments?

What other libc functions can be expected to destroy the alignment?

> it's IMHO best only to align the actual call to main and not compile anything
> with this switch (even more since this switch isn't available in every
> gcc version).

Could you please elaborate on the disadvantages of this switch, other
than non-support in older gcc versions?