Re: [hatari-devel] Bug in FPU code

[Laurent Sallafranque <laurent.sallafranque@xxxxxxx>]

Hi,

Eero, Thomas, Nicolas, I've tested the patch with the esquimau demo, but 
I haven't seen any change. (Eskimau does a lot of FPU).

As I'm not a specialist of #if USE_LONG_DOUBLE defines and the code 
after, I prefer asking you your advice on this patch before uploading 
anything.

Is the fix OK for any case of #if USE_LONG_DOUBLE ? (on every computer, 
.... little / big endian, ...) ?

At least, the patch doesn't seem to break anything, but I've done only 
one test.

Regards

Laurent


Le 05/03/2012 19:51, Andreas Grabher a écrit :
> While working on Previous i found a bug in the FPU code and fixed it. This makes the FPU pass NeXT's power-on test using 68040 with its internal FPU. 68030/68882 still not working but getting to the next stage now.
>
> I appended the patch to this message.
> As i am still new to coding, please check the code before applying the patch.
>
> Regards,
>
> Andreas
>
>
> diff -crB /Users/andi/Desktop/branch_scsiold/src/cpu/md-fpp.h /Users/andi/Desktop/branch_scsi/src/cpu/md-fpp.h
> *** /Users/andi/Desktop/branch_scsiold/src/cpu/md-fpp.h	2011-12-14 19:29:29.000000000 +0100
> --- /Users/andi/Desktop/branch_scsi/src/cpu/md-fpp.h	2012-03-05 19:09:33.000000000 +0100
> ***************
> *** 33,41 ****
>    STATIC_INLINE void from_exten(long double src, uae_u32 * wrd1, uae_u32 * wrd2, uae_u32 * wrd3)
>    {
>        register uae_u32 *longarray = (uae_u32 *)&src;
> !     register uae_u16 *finalword = (uae_u16 *)(&src + 8);
>
> !     *wrd1 = ((uae_u32)*finalword)<<16;
>        *wrd2 = longarray[1];
>        *wrd3 = longarray[0]; // little endian
>    }
> --- 33,42 ----
>    STATIC_INLINE void from_exten(long double src, uae_u32 * wrd1, uae_u32 * wrd2, uae_u32 * wrd3)
>    {
>        register uae_u32 *longarray = (uae_u32 *)&src;
> ! //    register uae_u16 *finalword = (uae_u16 *)(&src + 8);
>
> ! //    *wrd1 = ((uae_u32)*finalword)<<16;
> !     *wrd1 = (longarray[2]&  0xffff)<<16;
>        *wrd2 = longarray[1];
>        *wrd3 = longarray[0]; // little endian
>    }