Continuing the clean-up related to the catch-all math_private.h
header, this patch stops math_private.h from including fenv_private.h.
Instead, fenv_private.h is included directly from those users of
math_private.h that also used interfaces from fenv_private.h. No
attempt is made to remove unused includes of math_private.h, but that
is a natural followup.
(However, since math_private.h sometimes defines optimized versions of
math.h interfaces or __* variants thereof, as well as defining its own
interfaces, I think it might make sense to get all those optimized
versions included from include/math.h, not requiring a separate header
at all, before eliminating unused math_private.h includes - that
avoids a file quietly becoming less-optimized if someone adds a call
to one of those interfaces without restoring a math_private.h include
to that file.)
There is still a pitfall that if code uses plain fe* and __fe*
interfaces, but only includes fenv.h and not fenv_private.h or (before
this patch) math_private.h, it will compile on platforms with
exceptions and rounding modes but not get the optimized versions (and
possibly not compile) on platforms without exception and rounding mode
support, so making it easy to break the build for such platforms
accidentally.
I think it would be most natural to move the inlines / macros for fe*
and __fe* in the case of no exceptions and rounding modes into
include/fenv.h, so that all code including fenv.h with _ISOMAC not
defined automatically gets them. Then fenv_private.h would be purely
the header for the libc_fe*, SET_RESTORE_ROUND etc. internal
interfaces and the risk of breaking the build on other platforms than
the one you tested on because of a missing fenv_private.h include
would be much reduced (and there would be some unused fenv_private.h
includes to remove along with unused math_private.h includes).
Tested for x86_64 and x86, and tested with build-many-glibcs.py that
installed stripped shared libraries are unchanged by this patch.
* sysdeps/generic/math_private.h: Do not include <fenv_private.h>.
* math/fromfp.h: Include <fenv_private.h>.
* math/math-narrow.h: Likewise.
* math/s_cexp_template.c: Likewise.
* math/s_csin_template.c: Likewise.
* math/s_csinh_template.c: Likewise.
* math/s_ctan_template.c: Likewise.
* math/s_ctanh_template.c: Likewise.
* math/s_iseqsig_template.c: Likewise.
* math/w_acos_compat.c: Likewise.
* math/w_acosf_compat.c: Likewise.
* math/w_acosl_compat.c: Likewise.
* math/w_asin_compat.c: Likewise.
* math/w_asinf_compat.c: Likewise.
* math/w_asinl_compat.c: Likewise.
* math/w_ilogb_template.c: Likewise.
* math/w_j0_compat.c: Likewise.
* math/w_j0f_compat.c: Likewise.
* math/w_j0l_compat.c: Likewise.
* math/w_j1_compat.c: Likewise.
* math/w_j1f_compat.c: Likewise.
* math/w_j1l_compat.c: Likewise.
* math/w_jn_compat.c: Likewise.
* math/w_jnf_compat.c: Likewise.
* math/w_llogb_template.c: Likewise.
* math/w_log10_compat.c: Likewise.
* math/w_log10f_compat.c: Likewise.
* math/w_log10l_compat.c: Likewise.
* math/w_log2_compat.c: Likewise.
* math/w_log2f_compat.c: Likewise.
* math/w_log2l_compat.c: Likewise.
* math/w_log_compat.c: Likewise.
* math/w_logf_compat.c: Likewise.
* math/w_logl_compat.c: Likewise.
* sysdeps/aarch64/fpu/feholdexcpt.c: Likewise.
* sysdeps/aarch64/fpu/fesetround.c: Likewise.
* sysdeps/aarch64/fpu/fgetexcptflg.c: Likewise.
* sysdeps/aarch64/fpu/ftestexcept.c: Likewise.
* sysdeps/ieee754/dbl-64/e_atan2.c: Likewise.
* sysdeps/ieee754/dbl-64/e_exp.c: Likewise.
* sysdeps/ieee754/dbl-64/e_exp2.c: Likewise.
* sysdeps/ieee754/dbl-64/e_gamma_r.c: Likewise.
* sysdeps/ieee754/dbl-64/e_jn.c: Likewise.
* sysdeps/ieee754/dbl-64/e_pow.c: Likewise.
* sysdeps/ieee754/dbl-64/e_remainder.c: Likewise.
* sysdeps/ieee754/dbl-64/e_sqrt.c: Likewise.
* sysdeps/ieee754/dbl-64/gamma_product.c: Likewise.
* sysdeps/ieee754/dbl-64/lgamma_neg.c: Likewise.
* sysdeps/ieee754/dbl-64/s_atan.c: Likewise.
* sysdeps/ieee754/dbl-64/s_fma.c: Likewise.
* sysdeps/ieee754/dbl-64/s_fmaf.c: Likewise.
* sysdeps/ieee754/dbl-64/s_llrint.c: Likewise.
* sysdeps/ieee754/dbl-64/s_llround.c: Likewise.
* sysdeps/ieee754/dbl-64/s_lrint.c: Likewise.
* sysdeps/ieee754/dbl-64/s_lround.c: Likewise.
* sysdeps/ieee754/dbl-64/s_nearbyint.c: Likewise.
* sysdeps/ieee754/dbl-64/s_sin.c: Likewise.
* sysdeps/ieee754/dbl-64/s_sincos.c: Likewise.
* sysdeps/ieee754/dbl-64/s_tan.c: Likewise.
* sysdeps/ieee754/dbl-64/wordsize-64/s_lround.c: Likewise.
* sysdeps/ieee754/dbl-64/wordsize-64/s_nearbyint.c: Likewise.
* sysdeps/ieee754/dbl-64/x2y2m1.c: Likewise.
* sysdeps/ieee754/float128/float128_private.h: Likewise.
* sysdeps/ieee754/flt-32/e_gammaf_r.c: Likewise.
* sysdeps/ieee754/flt-32/e_j1f.c: Likewise.
* sysdeps/ieee754/flt-32/e_jnf.c: Likewise.
* sysdeps/ieee754/flt-32/lgamma_negf.c: Likewise.
* sysdeps/ieee754/flt-32/s_llrintf.c: Likewise.
* sysdeps/ieee754/flt-32/s_llroundf.c: Likewise.
* sysdeps/ieee754/flt-32/s_lrintf.c: Likewise.
* sysdeps/ieee754/flt-32/s_lroundf.c: Likewise.
* sysdeps/ieee754/flt-32/s_nearbyintf.c: Likewise.
* sysdeps/ieee754/k_standardl.c: Likewise.
* sysdeps/ieee754/ldbl-128/e_expl.c: Likewise.
* sysdeps/ieee754/ldbl-128/e_gammal_r.c: Likewise.
* sysdeps/ieee754/ldbl-128/e_j1l.c: Likewise.
* sysdeps/ieee754/ldbl-128/e_jnl.c: Likewise.
* sysdeps/ieee754/ldbl-128/gamma_productl.c: Likewise.
* sysdeps/ieee754/ldbl-128/lgamma_negl.c: Likewise.
* sysdeps/ieee754/ldbl-128/s_fmal.c: Likewise.
* sysdeps/ieee754/ldbl-128/s_llrintl.c: Likewise.
* sysdeps/ieee754/ldbl-128/s_llroundl.c: Likewise.
* sysdeps/ieee754/ldbl-128/s_lrintl.c: Likewise.
* sysdeps/ieee754/ldbl-128/s_lroundl.c: Likewise.
* sysdeps/ieee754/ldbl-128/s_nearbyintl.c: Likewise.
* sysdeps/ieee754/ldbl-128/x2y2m1l.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/e_expl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/e_gammal_r.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/e_j1l.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/e_jnl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/lgamma_negl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_fmal.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_llrintl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_llroundl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_lrintl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_lroundl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_rintl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/x2y2m1l.c: Likewise.
* sysdeps/ieee754/ldbl-96/e_gammal_r.c: Likewise.
* sysdeps/ieee754/ldbl-96/e_jnl.c: Likewise.
* sysdeps/ieee754/ldbl-96/gamma_productl.c: Likewise.
* sysdeps/ieee754/ldbl-96/lgamma_negl.c: Likewise.
* sysdeps/ieee754/ldbl-96/s_fma.c: Likewise.
* sysdeps/ieee754/ldbl-96/s_fmal.c: Likewise.
* sysdeps/ieee754/ldbl-96/s_llrintl.c: Likewise.
* sysdeps/ieee754/ldbl-96/s_llroundl.c: Likewise.
* sysdeps/ieee754/ldbl-96/s_lrintl.c: Likewise.
* sysdeps/ieee754/ldbl-96/s_lroundl.c: Likewise.
* sysdeps/ieee754/ldbl-96/x2y2m1l.c: Likewise.
* sysdeps/powerpc/fpu/e_sqrt.c: Likewise.
* sysdeps/powerpc/fpu/e_sqrtf.c: Likewise.
* sysdeps/riscv/rv64/rvd/s_ceil.c: Likewise.
* sysdeps/riscv/rv64/rvd/s_floor.c: Likewise.
* sysdeps/riscv/rv64/rvd/s_nearbyint.c: Likewise.
* sysdeps/riscv/rv64/rvd/s_round.c: Likewise.
* sysdeps/riscv/rv64/rvd/s_roundeven.c: Likewise.
* sysdeps/riscv/rv64/rvd/s_trunc.c: Likewise.
* sysdeps/riscv/rvd/s_finite.c: Likewise.
* sysdeps/riscv/rvd/s_fmax.c: Likewise.
* sysdeps/riscv/rvd/s_fmin.c: Likewise.
* sysdeps/riscv/rvd/s_fpclassify.c: Likewise.
* sysdeps/riscv/rvd/s_isinf.c: Likewise.
* sysdeps/riscv/rvd/s_isnan.c: Likewise.
* sysdeps/riscv/rvd/s_issignaling.c: Likewise.
* sysdeps/riscv/rvf/fegetround.c: Likewise.
* sysdeps/riscv/rvf/feholdexcpt.c: Likewise.
* sysdeps/riscv/rvf/fesetenv.c: Likewise.
* sysdeps/riscv/rvf/fesetround.c: Likewise.
* sysdeps/riscv/rvf/feupdateenv.c: Likewise.
* sysdeps/riscv/rvf/fgetexcptflg.c: Likewise.
* sysdeps/riscv/rvf/ftestexcept.c: Likewise.
* sysdeps/riscv/rvf/s_ceilf.c: Likewise.
* sysdeps/riscv/rvf/s_finitef.c: Likewise.
* sysdeps/riscv/rvf/s_floorf.c: Likewise.
* sysdeps/riscv/rvf/s_fmaxf.c: Likewise.
* sysdeps/riscv/rvf/s_fminf.c: Likewise.
* sysdeps/riscv/rvf/s_fpclassifyf.c: Likewise.
* sysdeps/riscv/rvf/s_isinff.c: Likewise.
* sysdeps/riscv/rvf/s_isnanf.c: Likewise.
* sysdeps/riscv/rvf/s_issignalingf.c: Likewise.
* sysdeps/riscv/rvf/s_nearbyintf.c: Likewise.
* sysdeps/riscv/rvf/s_roundevenf.c: Likewise.
* sysdeps/riscv/rvf/s_roundf.c: Likewise.
* sysdeps/riscv/rvf/s_truncf.c: Likewise.
This patch makes the dbl-64 atan and tan implementations use
libm_alias_double, removing the corresponding ldbl-opt wrappers.
Tested for x86_64, and with build-many-glibcs.py. Installed stripped
shared libraries are unchanged on non-ldbl-opt platforms. For
ldbl-opt configurations, the patch has the effect of causing
compat_symbol to define atanl and tanl in terms of __atan and __tan
instead of in terms of atan and tan, which is enough to change the
installed stripped libm.so.
* sysdeps/ieee754/dbl-64/s_atan.c: Include <libm-alias-double.h>.
(atan): Define using libm_alias_double.
* sysdeps/ieee754/dbl-64/s_tan.c: Include <libm-alias-double.h>.
(tan): Define using libm_alias_double.
* sysdeps/ieee754/ldbl-opt/s_atan.c: Remove file.
* sysdeps/ieee754/ldbl-opt/s_tan.c: Likewise.
This patch converts the dbl-64 implementations of atan and tan into
weak aliases of __atan and __tan, in preparation for making them use
libm_alias_double. Consequent changes are made to the x86_64
multiarch versions wrapping round them (with the dbl-64 functions,
like other such functions, being made not to define their aliases at
all if __atan or __tan are defined as macros by an including file).
Tested for x86_64, and with build-many-glibcs.py.
* sysdeps/ieee754/dbl-64/s_atan.c (atan): Rename to __atan and
define as weak alias of __atan. Do not define any aliases if
[__atan].
[NO_LONG_DOUBLE] (__atanl): Define as strong alias of __atan.
[NO_LONG_DOUBLE] (atanl): Define as weak alias of __atanl.
* sysdeps/ieee754/dbl-64/s_tan.c (tan): Rename to __tan and define
as weak alias of __tan. Do not define any aliases if [__tan].
[NO_LONG_DOUBLE] (__tanl): Define as strong alias of __tan.
[NO_LONG_DOUBLE] (tanl): Define as weak alias of __tanl.
* sysdeps/x86_64/fpu/multiarch/s_atan-avx.c (atan): Rename to
__atan.
* sysdeps/x86_64/fpu/multiarch/s_atan-fma.c (atan): Likewise.
* sysdeps/x86_64/fpu/multiarch/s_atan-fma4.c (atan): Likewise.
* sysdeps/x86_64/fpu/multiarch/s_atan.c (atan): Rename to __atan
and define as weak alias of __atan.
* sysdeps/x86_64/fpu/multiarch/s_tan-avx.c (tan): Rename to
__atan.
* sysdeps/x86_64/fpu/multiarch/s_tan-fma.c (tan): Likewise.
* sysdeps/x86_64/fpu/multiarch/s_tan-fma4.c (tan): Likewise.
* sysdeps/x86_64/fpu/multiarch/s_tan.c (tan): Rename to __tan and
define as weak alias of __tan.
Similar to various other bugs in this area, some tan implementations
do not raise the underflow exception for subnormal arguments, when the
result is tiny and inexact. This patch forces the exception in a
similar way to previous fixes.
Tested for x86_64, x86, mips64 and powerpc.
[BZ #16517]
* sysdeps/ieee754/dbl-64/s_tan.c: Include <float.h>.
(tan): Force underflow exception for arguments with small absolute
value.
* sysdeps/ieee754/flt-32/k_tanf.c: Include <float.h>.
(__kernel_tanf): Force underflow exception for arguments with
small absolute value.
* sysdeps/ieee754/ldbl-128/k_tanl.c: Include <float.h>.
(__kernel_tanl): Force underflow exception for arguments with
small absolute value.
* sysdeps/ieee754/ldbl-128ibm/k_tanl.c: Include <float.h>.
(__kernel_tanl): Force underflow exception for arguments with
small absolute value.
* sysdeps/ieee754/ldbl-96/k_tanl.c: Include <float.h>.
(__kernel_tanl): Force underflow exception for arguments with
small absolute value.
* math/auto-libm-test-in: Add more tests of tan.
* math/auto-libm-test-out: Regenerated.
Add systemtap probes to various slow paths in libm so that application
developers may use systemtap to find out if their applications are
hitting these slow paths. We have added probes for pow, exp, log,
tan, atan and atan2.
2001-03-12 Ulrich Drepper <drepper@redhat.com>
* sysdeps/ieee754/dbl-64/e_remainder.c: Fix handling of boundary
conditions.
* sysdeps/ieee754/dbl-64/e_pow.c: Fix handling of boundary
conditions.
* sysdeps/ieee754/dbl-64/s_sin.c (__sin): Handle Inf and NaN
correctly.
(__cos): Likewise.
* sysdeps/ieee754/dbl-64/e_asin.c (__ieee754_asin): Handle NaN
correctly.
(__ieee754_acos): Likewise.
redefinition.
* sysdeps/ieee754/dbl-64/endian.h: Define also one of BIG_ENDI and
LITTLE_ENDI.
* sysdeps/ieee754/dbl-64/MathLib.h (Init_Lib): Use void as
parameter list.
2001-03-11 Ulrich Drepper <drepper@redhat.com>
Last-bit accurate math library implementation by IBM Haifa.
Contributed by Abraham Ziv <ziv@il.ibm.com>, Moshe Olshansky
<olshansk@il.ibm.com>, Ealan Henis <ealan@il.ibm.com>, and
Anna Reitman <reitman@il.ibm.com>.
* math/Makefile (dbl-only-routines): New variable.
(libm-routines): Add $(dbl-only-routines).
* sysdeps/ieee754/dbl-64/e_acos.c: Empty, definition is in e_asin.c.
* sysdeps/ieee754/dbl-64/e_asin.c: Replaced with accurate asin
implementation.
* sysdeps/ieee754/dbl-64/e_atan2.c: Replaced with accurate atan2
implementation.
* sysdeps/ieee754/dbl-64/e_exp.c: Replaced with accurate exp
implementation.
* sysdeps/ieee754/dbl-64/e_lgamma_r.c: Don't use __kernel_sin and
__kernel_cos.
* sysdeps/ieee754/dbl-64/e_log.c: Replaced with accurate log
implementation.
* sysdeps/ieee754/dbl-64/e_remainder.c: Replaced with accurate
remainder implementation.
* sysdeps/ieee754/dbl-64/e_pow.c: Replaced with accurate pow
implementation.
* sysdeps/ieee754/dbl-64/e_sqrt.c: Replaced with accurate sqrt
implementation.
* sysdeps/ieee754/dbl-64/k_cos.c: Empty, definition is in s_sin.c.
* sysdeps/ieee754/dbl-64/k_sin.c: Empty, definition is in s_sin.c.
* sysdeps/ieee754/dbl-64/s_atan.c: Replaced with accurate atan
implementation.
* sysdeps/ieee754/dbl-64/s_cos.c: Empty, definition is in s_sin.c.
* sysdeps/ieee754/dbl-64/s_sin.c: Replaced with accurate sin/cos
implementation.
* sysdeps/ieee754/dbl-64/s_sincos.c: Rewritten to not use __kernel_sin
and __kernel_cos.
* sysdeps/ieee754/dbl-64/s_tan.c: Replaced with accurate tan
implementation.
* sysdeps/ieee754/dbl-64/Dist: Add new non-code files.
* sysdeps/ieee754/dbl-64/MathLib.h: New file.
* sysdeps/ieee754/dbl-64/asincos.tbl: New file.
* sysdeps/ieee754/dbl-64/atnat.h: New file.
* sysdeps/ieee754/dbl-64/atnat2.h: New file.
* sysdeps/ieee754/dbl-64/branred.c: New file.
* sysdeps/ieee754/dbl-64/branred.h: New file.
* sysdeps/ieee754/dbl-64/dla.h: New file.
* sysdeps/ieee754/dbl-64/doasin.c: New file.
* sysdeps/ieee754/dbl-64/doasin.h: New file.
* sysdeps/ieee754/dbl-64/dosincos.c: New file.
* sysdeps/ieee754/dbl-64/dosincos.h: New file.
* sysdeps/ieee754/dbl-64/endian.h: New file.
* sysdeps/ieee754/dbl-64/halfulp.c: New file.
* sysdeps/ieee754/dbl-64/mpa.c: New file.
* sysdeps/ieee754/dbl-64/mpa.h: New file.
* sysdeps/ieee754/dbl-64/mpa2.h: New file.
* sysdeps/ieee754/dbl-64/mpatan.c: New file.
* sysdeps/ieee754/dbl-64/mpatan.h: New file.
* sysdeps/ieee754/dbl-64/mpatan2.c: New file.
* sysdeps/ieee754/dbl-64/mpexp.c: New file.
* sysdeps/ieee754/dbl-64/mpexp.h: New file.
* sysdeps/ieee754/dbl-64/mplog.c: New file.
* sysdeps/ieee754/dbl-64/mplog.h: New file.
* sysdeps/ieee754/dbl-64/mpsqrt.c: New file.
* sysdeps/ieee754/dbl-64/mpsqrt.h: New file.
* sysdeps/ieee754/dbl-64/mptan.c: New file.
* sysdeps/ieee754/dbl-64/mydefs.h: New file.
* sysdeps/ieee754/dbl-64/powtwo.tbl: New file.
* sysdeps/ieee754/dbl-64/root.tbl: New file.
* sysdeps/ieee754/dbl-64/sincos.tbl: New file.
* sysdeps/ieee754/dbl-64/sincos32.c: New file.
* sysdeps/ieee754/dbl-64/sincos32.h: New file.
* sysdeps/ieee754/dbl-64/slowexp.c: New file.
* sysdeps/ieee754/dbl-64/slowpow.c: New file.
* sysdeps/ieee754/dbl-64/uasncs.h: New file.
* sysdeps/ieee754/dbl-64/uatan.tbl: New file.
* sysdeps/ieee754/dbl-64/uexp.h: New file.
* sysdeps/ieee754/dbl-64/uexp.tbl: New file.
* sysdeps/ieee754/dbl-64/ulog.h: New file.
* sysdeps/ieee754/dbl-64/ulog.tbl: New file.
* sysdeps/ieee754/dbl-64/upow.h: New file.
* sysdeps/ieee754/dbl-64/upow.tbl: New file.
* sysdeps/ieee754/dbl-64/urem.h: New file.
* sysdeps/ieee754/dbl-64/uroot.h: New file.
* sysdeps/ieee754/dbl-64/usncs.h: New file.
* sysdeps/ieee754/dbl-64/utan.h: New file.
* sysdeps/ieee754/dbl-64/utan.tbl: New file.
* sysdeps/i386/fpu/branred.c: New file.
* sysdeps/i386/fpu/doasin.c: New file.
* sysdeps/i386/fpu/dosincos.c: New file.
* sysdeps/i386/fpu/halfulp.c: New file.
* sysdeps/i386/fpu/mpa.c: New file.
* sysdeps/i386/fpu/mpatan.c: New file.
* sysdeps/i386/fpu/mpatan2.c: New file.
* sysdeps/i386/fpu/mpexp.c: New file.
* sysdeps/i386/fpu/mplog.c: New file.
* sysdeps/i386/fpu/mpsqrt.c: New file.
* sysdeps/i386/fpu/mptan.c: New file.
* sysdeps/i386/fpu/sincos32.c: New file.
* sysdeps/i386/fpu/slowexp.c: New file.
* sysdeps/i386/fpu/slowpow.c: New file.
* sysdeps/ia64/fpu/branred.c: New file.
* sysdeps/ia64/fpu/doasin.c: New file.
* sysdeps/ia64/fpu/dosincos.c: New file.
* sysdeps/ia64/fpu/halfulp.c: New file.
* sysdeps/ia64/fpu/mpa.c: New file.
* sysdeps/ia64/fpu/mpatan.c: New file.
* sysdeps/ia64/fpu/mpatan2.c: New file.
* sysdeps/ia64/fpu/mpexp.c: New file.
* sysdeps/ia64/fpu/mplog.c: New file.
* sysdeps/ia64/fpu/mpsqrt.c: New file.
* sysdeps/ia64/fpu/mptan.c: New file.
* sysdeps/ia64/fpu/sincos32.c: New file.
* sysdeps/ia64/fpu/slowexp.c: New file.
* sysdeps/ia64/fpu/slowpow.c: New file.
* sysdeps/m68k/fpu/branred.c: New file.
* sysdeps/m68k/fpu/doasin.c: New file.
* sysdeps/m68k/fpu/dosincos.c: New file.
* sysdeps/m68k/fpu/halfulp.c: New file.
* sysdeps/m68k/fpu/mpa.c: New file.
* sysdeps/m68k/fpu/mpatan.c: New file.
* sysdeps/m68k/fpu/mpatan2.c: New file.
* sysdeps/m68k/fpu/mpexp.c: New file.
* sysdeps/m68k/fpu/mplog.c: New file.
* sysdeps/m68k/fpu/mpsqrt.c: New file.
* sysdeps/m68k/fpu/mptan.c: New file.
* sysdeps/m68k/fpu/sincos32.c: New file.
* sysdeps/m68k/fpu/slowexp.c: New file.
* sysdeps/m68k/fpu/slowpow.c: New file.
* iconvdata/gconv-modules: Add a number of alias, mostly for IBM
codepages.
