Re: [hatari-devel] Re: FPU update

[Douglas Little <doug694@xxxxxxxxxxxxxx>]

Hi,

 

I hope Andreas have some ideas for FSGLxxx-errors but FABS/FNEG error is
confusing, does it mean some extra test is missing? I tried to check for
NaN and skip the operation if it was Nan but it didn't fix it.

Each test is usually repeated with 3 sources of float data:

BRAND = binary random data, including values which could be considered invalid

DRAND = double precision random source values from -1.0 -> +1.0 

ERAND = same as DRAND, but raised to a random exponent between -1024 -> +1023

So errors just in the BRAND tests for example, could indicate different handling of invalid or certain denormalised values.

Errors in DRAND tests might indicate general incorrect handling or general precision differences in the mantissa.

Errors in ERAND tests might indicate problems with denormalised values or exponent limits.

The 'negabs' test just performs neg and abs tests (separate, but results hashed together). A failure here might indicate funny handling of "negative zero"?

Doug.