[Help-smalltalk] [PATCH] fix FloatQ reading

[Paolo Bonzini]

Hi all and especially Nicolas,

here is my shotgun approach to fixing the reading of FloatQ.  The 
problem lies in Smalltalk's support for arbitrary bases, which does not 
allow me to use the optimized strtod function from the C library.

I decided to write my own tiny floating-point math library (I couldn't 
decide whether using mpf/mpfr was *more* or *less* shotgun) so that I 
can read the FP numbers in 160 bit precision.  This is somewhat dual to 
what the Smalltalk code does, which uses fractions and multi-precision 
integers, and it is also how GCC works by the way (though they have more 
stuff to do because of handling denormals, NaNs and infinities).

While I tried it a bit, there might be bugs, so I ask you all to figure 
out some stress tests.  These are needed because at some point all 
floats were returned multiplied by 2 :-) and "make" still built...  I 
tried on the ones from http://smalltalk.gnu.org/project/issue/313, as 
well as a few others like 1q3000/1q2999 or 3.6451995318824746025q-4951 
(FloatQ fmin), and they seem to work.  Ideas on how to incorporate these 
into floatmath.st as portably as possible are also welcome.

The code is already in git.

Paolo

gst-real-reading.patch
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