RFC: fp printing speedup patch

[Paolo Carlini]

Paolo Carlini wrote:

> Hi Jerry, thanks for your detailed message

One more comment, not really about performance, but about a general
design point: if you look at PR 12988, which I filed yesterday, you
may notice that we are doing bad on 2.2.2.2.2, p14: basically, after
"printing" the number as if printf was called and before grouping we
must call widen(char c) once for each char of the internal buffer in
order to *properly* convert the internal buffer to charT.

Therefore, after all, I don't think the various __*_to_char should be
templates parameterized on _CharT, but simple functions working on
chars, perhaps including the widen(c) loop at the end.

Paolo.