Re: GCC 3.4 Heads-up

[Andy Isaacson <adi@hexapodia.org>]

On Thu, Dec 25, 2003 at 08:34:33PM -0800, Linus Torvalds wrote:
> The cast/conditional expression as lvalue are _particularly_ ugly 
> extensions, since there is absolutely zero point to them. They are very 
> much against what C is all about, and writing something like this:
> 
> 	a ? b : c = d;
> 
> is something that only a high-level language person could have come up 
> with. The _real_ way to do this in C is to just do
> 
> 	*(a ? &b : &c) = d;
> 
> which is portable C, does the same thing, and has no strange semantics.

But doesn't the first one potentially let the compiler avoid spilling to
memory, if b and c are both in registers?

Not that I'm fond of gccisms, but this one at least seems to have a
potential value.  And I'm sure I came up with an instance of it making
my head ache, a while back, but I can't come up with a bad example now.
Care to elaborate on your "strange semantics"?

-andy