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Atari coding BBS
Re: 68882 testing program
Posted by: dml May,26.2015-14:17 

Having thought about it a bit, the fault probably falls in one of these areas:

- something going wrong with float->int conversion, both in compiler-generated code, and in attempts to use ASM FPU fragments to do the same thing. Maybe FPCR related (but somehow machine-sensitive in a way I can't yet fathom remotely).
- dirty/dry pin on the FPU or socket

It is weird that it behaves differently on two seemingly identical boxes, and in more than one area of the program, with neither machine loading anything significant in the way of AUTO software. The HD drivers do differ but that's the only major deviation.

As always, it's more likely to be a code bug but not ruling anything out at this stage. Would be nice to test the FPU properly just in case. Ideally something that uses float->int conversions and probably pow() as well, since the palette gamma step seems to be fouling up and it really only uses pow() and some int rounding...

While the problem does seem to get worse as I introduce ASM fragments for FPU work, it is still present with just plain C compilation. It only goes away 100% when forcing -msoft-float or targeting 68000 code with the compiler...

In any case I'll make some more specific tests but general tests are just as valuable.

[All messages in this thread]

Topic Posted by  Date 
68882 testing program Laurent / Thadoss May,26.2015-11:20
  Re: 68882 testing program dml May,26.2015-14:17
    Re: 68882 testing program Laurent / Thadoss Jun,02.2015-00:34
    Re: 68882 testing program Laurent / Thadoss Jun,02.2015-00:40
      Re: 68882 testing program dml Jun,02.2015-00:53
        Re: 68882 testing program ggn Jun,04.2015-08:48
          Re: 68882 testing program evil Jun,04.2015-16:46
            Re: 68882 testing program dml Jun,04.2015-19:23
          Re: 68882 testing program dml Jun,04.2015-19:22
            Re: 68882 testing program gwEm/PHF Jun,05.2015-11:42
              Re: 68882 testing program dml Jun,05.2015-13:43
                Re: 68882 testing program evil Jun,05.2015-18:36
                  Re: 68882 testing program Laurent / Thadoss Jun,05.2015-21:46

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