__strong_alias is an ELF feature that is not available on Darwin/MachO.
We have openlibm_strong_reference to paper over these differences,
but we weren't using it consistently. In particular, we were still
using it to define long double -> double aliases on platforms where
these are the same type (e.g. aarch64). This didn't used to matter,
because the only such platform we supported was always Linux and
thus ELF. This patch fixes these instances thus fixing the build
on Apple Silicon.
On x86_64, openlibm_fenv.h is silently coupled to openlibm_complex.h due to the inclusion of math_private.h inside of openlibm_fenv_amd64.h. The math_private.h header was included to gain access to the OLM_DLLEXPORT macro. However, this macro is redefined, since it is originally defined in openlibm_math.h. This inclusion also exposes math_private.h to public clients, which is undesirable.
Instead, a standalone header is created to contain the OLM_DLLEXPORT definition. This header is used included in the appropriate files. openlibm_fenv_amd64.h is no longer coupled to math_private.h.
Changes needed for mips suport have been added.
Code for openlibm_fenv_mips.h, mips_fpmath.h and fenv.c
was taken from https://github.com/freebsd/freebsd
As a component of atan2(y, x), the case of x == 1.0 is farmed out to
atan(y). The current implementation of this comparison is vulnerable
to signed integer underflow (that is, undefined behavior), and it's
performed in a somewhat more complicated way than it need be. Change
it to not be quite so cute, rather directly comparing the high/low
bits of x to the specific IEEE-754 bit pattern that encodes 1.0.
Note that while there are three different e_atan* files in the
relevant directory, only this one needs fixing. e_atan2f.c already
compares against the full bit pattern encoding 1.0f, while
e_atan2l.cuses bitwise-ands/ors/nots and so doesn't require a change.
Incorporated from FreeBSD source tree. See:
b21ccf63f2
