Re: i386 FP comparsion bug (and sollution)

[Marc Lehmann <pcg at goof dot com>]

On Mon, Nov 02, 1998 at 09:31:25AM -0700, Jeffrey A Law wrote:
> 
> 
>   In message <19981102012555.D7828@cerebro.laendle>you write:
>   > I can remember that I explicitly allowed inserting (some) instructions
>   > between the setter and the user (in pgcc), and it worked fine with fp-code.
>   > Unfortunately I can't remember the details ;) as usual.. The code is buggy,
>   > but in practise works perfect (I never reeceived a bug-report that was
>   > caused by it).
> But the kind of bugs that will occur by putting insns between the setter and
> user are going to be very obscure.  I wouldn't be suprised if you hadn't seen
> anything fail because of this.  That does not mean what pgcc does is correct.

Nor does this mean the code generated by gcc is correct ;) There are quite a
few illegal assumptions in pgcc that would not be acceptable in egcs, but
work very well in practise (not that egcs isn't catching up quickly).

I didn't plea for getting rid of the checks in final.c ;)

> problems.  One could consider rewriting the x86 port to not use cc0, or
> revamping passes from final.c backwards to lift this restriction, but it's
> a lot of work with unclear benefits.

Well, this should be remembered when the x86 port is rewritten the next time
;-> Volunteers, anybody?

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