glibc/math/w_pow_compat.c
Szabolcs Nagy a502c5294b Remove the error handling wrapper from pow
Introduce new pow symbol version that doesn't do SVID compatible error
handling.  The standard errno and fp exception based error handling is
inline in the new code and does not have significant overhead.

The wrapper is disabled for sysdeps/ieee754/dbl-64 by using empty
w_pow.c and enabled for targets with their own pow implementation or
ifunc dispatch on __ieee754_pow by including math/w_pow.c.

The compatibility symbol version still uses the wrapper with SVID error
handling around the new code.  There is no new symbol version nor
compatibility code on !LIBM_SVID_COMPAT targets (e.g. riscv).

On targets where previously powl was an alias of pow, now it points to
the compatibility symbol with the wrapper, because it still need the
SVID compatible error handling.  This affects NO_LONG_DOUBLE (e.g. arm)
and LONG_DOUBLE_COMPAT (e.g. alpha) targets as well.

The __pow_finite symbol is now an alias of pow.  Both __pow_finite and
pow set errno and thus not const functions.

The ia64 asm is changed so the compat and new symbol versions map to the
same address.

On x86_64 #include <math.h> was added before macro definitions that
may affect that header.

Tested with build-many-glibcs.py.

	* math/Versions (GLIBC_2.29): Add pow.
	* math/w_pow_compat.c (__pow_compat): Change to versioned compat
	symbol.
	* math/w_pow.c: New file.
	* sysdeps/i386/fpu/w_pow.c: New file.
	* sysdeps/ia64/fpu/e_pow.S: Add versioned symbols.
	* sysdeps/ieee754/dbl-64/e_pow.c (__ieee754_pow): Rename to __pow
	and add necessary aliases.
	* sysdeps/ieee754/dbl-64/w_pow.c: New file.
	* sysdeps/m68k/m680x0/fpu/w_pow.c: New file.
	* sysdeps/mach/hurd/i386/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/aarch64/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/alpha/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/arm/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/hppa/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/i386/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/ia64/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/m68k/coldfire/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/m68k/m680x0/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/microblaze/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/mips/mips32/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/nios2/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist: Update.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/s390/s390-32/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/sh/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Update.
	* sysdeps/x86_64/fpu/multiarch/e_pow-fma.c (__ieee754_pow): Rename to
	__pow.
	* sysdeps/x86_64/fpu/multiarch/e_pow-fma4.c (__ieee754_pow): Likewise.
	* sysdeps/x86_64/fpu/multiarch/e_pow.c (__ieee754_pow): Likewise.
	* sysdeps/x86_64/fpu/multiarch/w_pow.c: New file.
2018-11-21 09:58:36 +00:00

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2.3 KiB
C

/* Copyright (C) 2011-2018 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@gmail.com>, 2011.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <math.h>
#include <math_private.h>
#include <math-svid-compat.h>
#include <libm-alias-double.h>
#if LIBM_SVID_COMPAT && (SHLIB_COMPAT (libm, GLIBC_2_0, GLIBC_2_29) \
|| defined NO_LONG_DOUBLE \
|| defined LONG_DOUBLE_COMPAT)
/* wrapper pow */
double
__pow_compat (double x, double y)
{
double z = __ieee754_pow (x, y);
if (__glibc_unlikely (!isfinite (z)))
{
if (_LIB_VERSION != _IEEE_)
{
if (isfinite (x) && isfinite (y))
{
if (isnan (z))
/* pow neg**non-int */
return __kernel_standard (x, y, 24);
else if (x == 0.0 && y < 0.0)
{
if (signbit (x) && signbit (z))
/* pow(-0.0,negative) */
return __kernel_standard (x, y, 23);
else
/* pow(+0.0,negative) */
return __kernel_standard (x, y, 43);
}
else
/* pow overflow */
return __kernel_standard (x, y, 21);
}
}
}
else if (__builtin_expect (z == 0.0, 0)
&& isfinite (x) && x != 0 && isfinite (y)
&& _LIB_VERSION != _IEEE_)
/* pow underflow */
return __kernel_standard (x, y, 22);
return z;
}
# if SHLIB_COMPAT (libm, GLIBC_2_0, GLIBC_2_29)
compat_symbol (libm, __pow_compat, pow, GLIBC_2_0);
# endif
# ifdef NO_LONG_DOUBLE
weak_alias (__pow_compat, powl)
# endif
# ifdef LONG_DOUBLE_COMPAT
/* Work around gas bug "multiple versions for symbol". */
weak_alias (__pow_compat, __pow_compat_alias)
LONG_DOUBLE_COMPAT_CHOOSE_libm_powl (
compat_symbol (libm, __pow_compat_alias, powl, FIRST_VERSION_libm_powl), );
# endif
#endif