> On Oct 17, 2016, at 8:42 PM, Nelson H. F. Beebe <be...@math.utah.edu> wrote:
> Some current compilers, such as releases of gcc for the last several
> years, use the GMP and MPFR multiple-precision arithmetic packages to
> supply correct compile-time conversions. Presumably, the revision
> history of GNU glibc would reveal when similar actions were taken for
> the strtod(), printf(), and scanf() families of the C and C++
> programming languages. I have not personally investigated that point,
> but perhaps other list members have, and can report their findings.
I don't think MPFR etc. apply to glibc. The reason GCC uses those libraries is
for cross-compilation: you can't use IEEE float when the target uses some other
float format. The floating point support (in file real.c primarily) is table
driven and has entries to handle all the formats that supported GCC targets
use. For example, I did some work there on the DEC float support. Among other
things, GCC can handle oddball cases such as the IBM 360 architecture with its
power-of-16 rather than power-of-2 encoding.
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