From: Camm Maguire <[EMAIL PROTECTED]> Greetings, and thanks for pointing this out. Actually, I maintain a few numerical packages requiring this flag on m68k to pass the regression tests in the package (gcl/maxima, atlas, blas, lapack,...). I suppose the sacrifice of performance is the correct approach. Anyone actually using the 68k with a different opinion will likely sway my mind in the other direction :). This would of course require sidestepping integrity tests in this case, as I won't have the time to maintain dual sets of expected results.
I actually think you have done the wise thing, but if any 68K fanatics insist otherwise, I've just checked my venerable 68881/68882 manual. There is a two-bit field in the FPCR Mode Control Byte that specifies the rounding precision for any fp calculation, and setting it forces IEEE-standard calculation. The manual warns, however, that these are intended for emulation of machines that only support these precisions, and that there is a significant speed cost when the single- or double-float rounding is turned on. Also, OS's and libraries make it nototiously difficult to manupulate FP control registers, and are even more notoriously sloppy about preserving the values in control registers.
