Put external headers before internal ones. While there, replace a lot of
occurences of "openlibm.h" with <openlibm.h>. It should be thought of as
an external header, as it is installed along with the library.
We already provide lgammaf_r() and lgamma_r(). It's not hard to also add
lgammal_r(), for consistency.
I am currently working on porting openlibm to an environment where
global state, and thus signgam, is not available. By adding lgammal_r(),
I can trivially disable support for signgam by just patching up
src/e_lgamma{f,,l}.c. That way there is no need to patch up the actual
algorithms.
Letting tgammal() modify signgam has two disadvantages:
- It breaks valid code that assumes that the value of signgam is not
clobbered by calls to tgammal().
- It makes this function depend on the presence of signgam. signgam is
an X/Open System Interface. It is not part of the C standard.
A couple of small issues still remain with linking:
LINK all
/usr/bin/ranlib: file: libopenlibm.a(e_rem_pio2.o) has no symbols
/usr/bin/ranlib: file: libopenlibm.a(e_rem_pio2f.o) has no symbols
/usr/bin/ranlib: file: libopenlibm.a(k_cosf.o) has no symbols
/usr/bin/ranlib: file: libopenlibm.a(k_sinf.o) has no symbols
/usr/bin/ranlib: file: libopenlibm.a(k_tanf.o) has no symbols
LINK all
ld: duplicate symbol ___ieee754_rem_pio2 in src/s_sin.o and src/s_cos.o for architecture x86_64
collect2: ld returned 1 exit status
