Re: Infinite loop with GCC 4.3

[David Kastrup]

"Han-Wen Nienhuys" <address@hidden> writes:

> 2008/5/26 Karl Hammar <address@hidden>:
>>> comment #60 sounds promising too. We'd have to have a small bit of
>>> system dependent code, but it is localized, so I can live with it.
>>
>> David Monniaux discusses this problem on page 15-17 of [1].
>>
>> His recommondation is to skip using the x87 fpu and use the sse fpu
>> instead. For this you don't need to add any code to the progran, but you
>> have the problem of not supporting x86 cpus without sse fpu, and you
>> have to specify target architecture.
>
> People that know what machine they are running on could do this or are
> running Gentoo could do this,  but I think that for the x87 hack is
> less of a support headache.

Would it help to use the following option when compiling?

`-ffloat-store'
     Do not store floating point variables in registers, and inhibit
     other options that might change whether a floating point value is
     taken from a register or memory.

     This option prevents undesirable excess precision on machines such
     as the 68000 where the floating registers (of the 68881) keep more
     precision than a `double' is supposed to have.  Similarly for the
     x86 architecture.  For most programs, the excess precision does
     only good, but a few programs rely on the precise definition of
     IEEE floating point.  Use `-ffloat-store' for such programs, after
     modifying them to store all pertinent intermediate computations
     into variables.

I mean, the last sentence sounds like a real pain, too.  But maybe it is
not necessary?


-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum