Continuing the process of setting up common macros for libm function
aliases, with a view to using them to define _FloatN / _FloatNx
aliases in future, this patch adds a libm_alias_double macro and uses
it in the type-generic templates.
This macro handles defining aliases for double, and for long double in
the NO_LONG_DOUBLE case. It also handles defining compat symbols for
long double = double for architectures that changed their long double
format. By so doing, it eliminates the need for the
M_LIBM_NEED_COMPAT and declare_mgen_libm_compat macros; the single
declare_mgen_alias call in each template now suffices to define all
required compat symbols. When used for more double functions (not
based on type-generic templates), I expect it will eliminate the need
for most ldbl-opt wrappers for such functions.
A few special cases are needed. __clog10l is a public symbol (for
historical reasons) so needs to be given appropriate compat versions
for architectures that changed their long double format, but is not
defined as an alias using the normal macros since __clog10* are *not*
public symbols for _FloatN / _FloatNx types. For scalbn, scalbln and
log1p, the changes adding errno setting support for those functions
left compat symbols pointing directly to the non-errno-setting
implementations. There is no requirement for the compat symbols not
to set errno; that just made for the simplest patches at that time.
Now, with these common macros, it's natural to redirect the compat
symbols to the errno-setting wrappers, which I intend to do in a
separate patch.
Tested for x86_64, and with build-many-glibcs.py. For ldbl-opt
platforms the stripped libm.so binaries are changed (disassembly
unchanged) because the details of how the clog10l compat symbol is
created mean it ceases to be weak as it was before; for other
platforms, stripped libm.so binaries are unchanged.
2017-09-13 Joseph Myers <joseph@codesourcery.com>
* sysdeps/generic/libm-alias-double.h: New file.
* sysdeps/ieee754/ldbl-opt/libm-alias-double.h: Likewise.
* sysdeps/generic/math-type-macros-double.h: Include
<libm-alias-double.h>.
[declare_mgen_alias] (declare_mgen_alias): Define to use
libm_alias_double.
* sysdeps/generic/math-type-macros.h [!M_LIBM_NEED_COMPAT]
(M_LIBM_NEED_COMPAT): Remove macro.
[!M_LIBM_NEED_COMPAT] (declare_mgen_libm_compat): Likewise.
* sysdeps/ieee754/ldbl-opt/math-type-macros-double.h: Remove.
* math/cabs_template.c [M_LIBM_NEED_COMPAT]: Remove conditional
code.
* math/carg_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/cimag_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/conj_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/creal_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_cacos_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_cacosh_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_casin_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_casinh_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_catan_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_catanh_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_ccos_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_ccosh_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_cexp_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_clog10_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_clog_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_cpow_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_cproj_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_csin_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_csinh_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_csqrt_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_ctan_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_ctanh_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_fdim_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_fmax_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_fmin_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_nan_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/w_ilogb_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* sysdeps/ieee754/ldbl-opt/s_clog10.c: New file.
* sysdeps/ieee754/ldbl-opt/s_ldexp.c (M_LIBM_NEED_COMPAT): Remove
macro.
(declare_mgen_alias): New macro.
* sysdeps/ieee754/ldbl-opt/w_log1p.c: New file.
* sysdeps/ieee754/ldbl-opt/w_scalbln.c: Likewise.
* sysdeps/sparc/sparc32/sparcv9/fpu/multiarch/s_fdim-vis3.c
(M_LIBM_NEED_COMPAT): Remove macro.
* sysdeps/sparc/sparc32/sparcv9/fpu/multiarch/s_fdim.c
[HAVE_AS_VIS3_SUPPORT]: Include <math_ldbl_opt.h> and
<first-versions.h>.
[HAVE_AS_VIS3_SUPPORT && LONG_DOUBLE_COMPAT (libm,
FIRST_VERSION_libm_fdiml)]: Define fdiml as compat symbol.
Some of the complex arithmetic functions have the following pattern:
in some piece of code, one part of the input (real or imaginary,
depending on the function) is either infinite or NaN. Part of the
result is to be set to NaN in either case, and FE_INVALID raised only
if the relevant part of the input was infinite.
In such a case, there is no actual need for the conditional on the
type of the input, since subtracting the relevant part of the input
from itself will produce a NaN, with FE_INVALID only if the relevant
part of the input was infinite. This simplifies the code, and as a
quality-of-implementation matter also improves things by propagating
NaN payloads. (Right now these functions always raise FE_INVALID for
signaling NaN arguments because of the call to fpclassify - at least
unless glibc is built with -Os - but if fpclassify moves to using
integer arithmetic in future, doing arithmetic on the NaN argument
also ensures an exception for sNaNs.)
Tested for x86_64 and x86.
* math/s_ccosh_template.c (M_DECL_FUNC (__ccosh)): Instead of
raising FE_INVALID with feraisexcept in case where part of
argument is infinite, subtract that part of argument from itself.
* math/s_cexp_template.c (M_DECL_FUNC (__cexp)): Likewise.
* math/s_csin_template.c (M_DECL_FUNC (__csin)): Likewise.
* math/s_csinh_template.c (M_DECL_FUNC (__csinh)): Likewise.
Some libm complex functions have code that computes M_NAN + M_NAN.
This is nonsensical; it's just equivalent to M_NAN, since it's a quiet
NaN (and the comments suggesting this raises an exception are
similarly wrong). This patch changes the code just to use M_NAN (and
removes the bogus comments). (Preferably, code should either
propagate an input NaN or do a computation that raises "invalid" and
generates a default NaN at the same time. There are various cases,
however, that currently raise "invalid" even for NaN inputs; I think
those are cases where "invalid" is optional in ISO C so a change to
whether it's raised would be OK, but they would still need more
careful consideration than the cases where such issues do not arise.)
Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by the patch).
* math/s_ccosh_template.c (M_DECL_FUNC (__ccosh)): Use M_NAN
instead of M_NAN + M_NAN.
* math/s_csinh_template.c (M_DECL_FUNC (__csinh)): Likewise.
This patch has no function changes, except to
ensure the git history correctly tracks the
changes to convert the double version of these
functions into a templated version.
