bug caused by this instruction:
fmove.l fp0,d0
problem was caused by a conflict between the fpu emulator (softfloat) and the compiler.
the emulator implemented this as a purely arithmetic move & conversion,
but the compiler assumed that the result could be interpreted as a logical (ie unsigned) conversion.
rightly or wrongly.
for example, if fp0 contained the value 2576980377.0 which is unsigned integer -1717987328
the emulator would treat this as an integer overflow and move 0x7fffffff (INT_MAX) into d0.
The complier on the other hand would assume that d0 contained 2576980377 (the unsigned value).
I don't know which is correct, but this is my fix for the time being.
6fe335b9e9