[hatari-devel] Native FPU emulation

[Thorsten Otto <admin@xxxxxxxxxxx>]

Hi,

 

while trying to debug an application, i just noticed that Hatari does not seem to use long doubles when using native emulation (USE_LONG_DOUBLE is not defined). Wouldn't it make sense to use at least the long double format when available, to be closer to the m68k format, even if that will not be as accurate as the softfloat emulation?

 

Also, in uae_cpu/newcpu.h, USE_LONG_DOUBLE is defined, but to a zero value. However in other places ifdef is used, which will still be true.

 

And if i understand the code correctly, the softfloat emulation solely uses the fpdata.fpx member, while the native emulation only uses fpdata.fp. When switching the emulation type at runtime, i can't see any attempt to convert from one field to the other (unless i missed something). Instead, it seems to reset the FPU registers to all NANs. Is that intended?

 

And the file cpu/md-fpp.h does not seem to be used at all.