[Python-Dev] RE: [Spambayes] Question (or possibly a bug report)

Tim Peters tim.one@comcast.net
Wed, 23 Jul 2003 23:51:49 -0400

[Mark Hammond]
> ...
> Googling for this, I found a mail Tim should find either interesting
> or terrifying - it mentions not only locale issues, but floating point
> exception masks:
> http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&oe=utf-8&threadm=
> %23MuH%23LU8BHA.2344%40tkmsftngp04

Heh.  I'm only surprised the guy got pointed to printer drivers so fast!  In
Dragon's core speech recognition engine, we had mounds of paranoid code
assuming that any call to anything we didn't write would screw up the FPU
control registers.  Driver writers seem to believe they need to fiddle every
bit the hardware exposes, but they're incompetent to do so <wink>.

Python has ignored this issue so far -- just as it's ignored almost all 754
issues.  I'm surprised that nobody in PythonLand has ever reported a bug of
this nature.  Maybe those who experience it just write it off to general
Windows flakiness ... but it shouldn't matter to spambayes.  The fp
arithmetic in spambayes should never overflow, underflow, or divide by 0, no
matter how extreme the inputs -- and I know what each of the bits in the FPU
control registers actually do <wink>.