Unifying the x86 FPU register sets

Eli Zaretskii eliz@gnu.org
Thu Oct 21 08:20:00 GMT 1999


> Note that in `tm-go32.h' there is a
> 
>    #undef TARGET_LONG_DOUBLE_BIT
>    #define TARGET_LONG_DOUBLE_BIT 96
> 
> So DJGPP is already treating the 80-bit extended types as a 96-bit
> type.

Why, of course! ;-)  That's because somebody noticed, a long time ago,
that this is required in order to get 80-bit registers supported.

> Then it will be very easy to support the i387 data registers as `long
> doubles' on hosts that have an equivalent type, without the LD_387
> kludge that's now used by DJGPP and Linux/i386.

I'm not sure.  There's a related issue of whether the library supports
long double in scanf and printf families of functions.  (There's also
the issue of the compiler support for long double, but it's a
non-issue for DJGPP and Linux ;-)

Would your suggestion handle all of these considerations?


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