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Date: Sun, 21 Dec 2003 19:41:12 +0200
From: "Eli Zaretskii" <eliz AT elta DOT co DOT il>
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To: Richard Dawe <rich AT phekda DOT gotadsl DOT co DOT uk>
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In-reply-to: <3FE5DB66.8000108@phekda.gotadsl.co.uk> (message from Richard
	Dawe on Sun, 21 Dec 2003 17:41:58 +0000)
Subject: Re: isnanf et al
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> Date: Sun, 21 Dec 2003 17:41:58 +0000
> From: Richard Dawe <rich AT phekda DOT gotadsl DOT co DOT uk>
> >>
> >>That would break the build with gcc 3.3.x (and 3.2.x?). Those changes 
> >>were made, so that DJGPP 2.04 could be built with gcc 3.3.x (and 3.2.x?).
> > 
> > 
> > Can you remind what kind of problems were those?  I think we should
> > look for a solution that fixes them without triggering this new
> > problem.
> 
> They were errors about type-punning breaking strict aliasing (search the 
> gcc info docs for -fstrict-aliasing and you should find a section about 
> it). Using a union is the only valid way of doing type-punning, but it 
> seems that using it was the wrong solution. By using the union I guess 
> you're telling the compiler "I know what I'm doing", like with typecasts.

Sorry, I'm confused: where is that solution using unions?  I'm
looking at ieeefp.h, the header that caused trouble reported by K.B.,
and I still see monstrocities like this:

    #define isnanf(x) (((*(long *)&(x) & 0x7f800000L)==0x7f800000L) && \
		       ((*(long *)&(x) & 0x007fffffL)!=0000000000L))

What am I missing?