where necessary.
The log1p() function is provided to compute an accurate value of
log(1 + x), even for tiny values of x. The i387 FPU provides the
fyl2xp1 instruction for this purpose.
However, since the range of the fyl2xp1 function is limited to
-(1 - (sqrt(2) / 2)) <= x <= sqrt(2) - 1
(-0.292893 <= x <= 0.414214)
we need to check if the argument is in the valid range.
In order to reduce the cost for testing the range, we only use
fyl2xp1 if the argument is in the range
-0.25 <= x <= 0.25
which can be checked with just one conditional branch.
Fixes PR lib/22599 by Ray Brownrigg.
of 3rd party software expects this.
XXX TODO: consider libm-fast for alpha that is not -mieee. Possibly
determine -mieee or not at run-time based on a bit in the executable
headers.
- SHLIBDIR Location to install shared libraries if ${USE_SHLIBDIR}
is "yes". Defaults to "/usr/lib".
- USE_SHLIBDIR If "yes", install shared libraries in ${SHLIBDIR}
instead of ${LIBDIR}. Defaults to "no".
Sets ${_LIBSODIR} to the appropriate value.
This may be set by individual Makefiles as well.
- SHLINKDIR Location of shared linker. Defaults to "/usr/libexec".
If != "/usr/libexec", change the dynamic-linker
encoded in shared programs
* Set USE_SHLIBDIR for libraries used by /bin and /sbin:
libc libcrypt libcrypto libedit libipsec libkvm libm libmi387
libtermcap libutil libz
* If ${_LIBSODIR} != ${LIBDIR}, add symlinks from ${LIBDIR}/${LIB}.so*
to ${_LIBSODIR}/${LIB}.so* for compatibility.
* Always install /sbin/init statically (for now)
The net effect of these changes depends on how the variables are set:
1.) If nothing is set or changed, there is no change from the
current behaviour:
- Static /bin, /sbin, and bits of /usr/*
- Dynamic rest
- Shared linker is /usr/libexec/ld*so
2.) If the following make variables are set:
LDSTATIC=
SHLINKDIR=/lib
SHLIBDIR=/lib
Then the behaviour becomes:
- Dynamic tools
- .so libraries used by /bin and /sbin are installed to /lib,
with symlinks from /usr/lib/lib*so to -> /lib/lib*so
where appropriate
- Shared linker is /lib/ld*so
3.) As per 2.), but add the following variable:
USE_SHLIBDIR=yes
This forces all .so's to be instaleld in /lib (with compat
symlinks), not just those tagged by their Makefiles to be.
Again, compat symlinks are installed
