[Victor]
> In pyport.h, you redefine PYLONG_BITS_IN_DIGIT if it's not set. Is 
> it for the Windows world (which doesn't use configure script)?

Yes, but it's also for Unix: PYLONG_BITS_IN_DIGIT is only set when the --
enable-big-digits option is supplied to configure.  So the code in 
pyport.h always gets used for a plain ./configure && make.

> I love fixed size type: you use them when PYLONG_BITS_IN_DIGIT == 
> 30 (eg. digit=PY_UINT32_T) but not when PYLONG_BITS_IN_DIGIT == 15 
> (eg. digit=unsigned short). Even if short is always 16 bits, I would 
> prefer fixed size types in any case.

I agree with you to some extent, but I'd still prefer to leave the 15-bit 
definitions as they are, partly out of a desire not to make unnecessary 
changes.  The 'unsigned short' type used for 15-bit digits is both 
theoretically sufficient and not wasteful in practice.

Barring further objections, I'm planning to get the 
30bit_longdigit20.patch in later this week.