Re: Failed float self test on OS X 10.5 with PowerPC

[Bruno Haible]

Hi Jeffrey,

> I think Bruno and I were talking about this for a while back in 2018
> or 2019. Gnulib was failing one self test due to floats on OS X 10.5
> on PowerPC....

Do you have a pointer to the mail archives? What was my reply back then?
Probably it was a reference to
  https://www.gnu.org/software/gnulib/manual/html_node/Target-Platforms.html
and "I know, I'm seeing this too, but Mac OS X/PowerPC is a platform of the
past, not of the future".

> $ gcc -O1 test.c -o test.exe
> $ ./test.exe
> sizeof(long double): 16
> LDBL_MANT_DIG: 106
> LDBL_MIN_EXP: -968
> LDBL_MAX_EXP: 1024
> LDBL_DIG: 31
> LDBL_MIN_10_EXP: -291
> LDBL_MAX_10_EXP: 308

That's what I'm seeing as well on
  - Mac OS X 10.4/PowerPC
  - Mac OS X 10.5 with CC="gcc -arch ppc"

> $ gcc -O1 -mlong-double-64 test.c -o test.exe
> $ ./test.exe
> sizeof(long double): 8
> LDBL_MANT_DIG: 53
> LDBL_MIN_EXP: -1021
> LDBL_MAX_EXP: 1024
> LDBL_DIG: 15
> LDBL_MIN_10_EXP: -307
> LDBL_MAX_10_EXP: 308

We really don't have time to worry about ABIs that are binary incompatible
to the default ABI of a platform.

There are *tons* of GCC options that cause binary incompatible code to be
generated by GCC:
https://gcc.gnu.org/onlinedocs/gcc-9.3.0/gcc/Submodel-Options.html
There's no point in spending time on supporting any of these in gnulib.

Bruno