glibc/sysdeps/generic/math-narrow-alias.h
Joseph Myers abd383584b Add narrowing square root functions
This patch adds the narrowing square root functions from TS 18661-1 /
TS 18661-3 / C2X to glibc's libm: fsqrt, fsqrtl, dsqrtl, f32sqrtf64,
f32sqrtf32x, f32xsqrtf64 for all configurations; f32sqrtf64x,
f32sqrtf128, f64sqrtf64x, f64sqrtf128, f32xsqrtf64x, f32xsqrtf128,
f64xsqrtf128 for configurations with _Float64x and _Float128;
__f32sqrtieee128 and __f64sqrtieee128 aliases in the powerpc64le case
(for calls to fsqrtl and dsqrtl when long double is IEEE binary128).
Corresponding tgmath.h macro support is also added.

The changes are mostly similar to those for the other narrowing
functions previously added, so the description of those generally
applies to this patch as well.  However, the not-actually-narrowing
cases (where the two types involved in the function have the same
floating-point format) are aliased to sqrt, sqrtl or sqrtf128 rather
than needing a separately built not-actually-narrowing function such
as was needed for add / sub / mul / div.  Thus, there is no
__nldbl_dsqrtl name for ldbl-opt because no such name was needed
(whereas the other functions needed such a name since the only other
name for that entry point was e.g. f32xaddf64, not reserved by TS
18661-1); the headers are made to arrange for sqrt to be called in
that case instead.

The DIAG_* calls in sysdeps/ieee754/soft-fp/s_dsqrtl.c are because
they were observed to be needed in GCC 7 testing of
riscv32-linux-gnu-rv32imac-ilp32.  The other sysdeps/ieee754/soft-fp/
files added didn't need such DIAG_* in any configuration I tested with
build-many-glibcs.py, but if they do turn out to be needed in more
files with some other configuration / GCC version, they can always be
added there.

I reused the same test inputs in auto-libm-test-in as for
non-narrowing sqrt rather than adding extra or separate inputs for
narrowing sqrt.  The tests in libm-test-narrow-sqrt.inc also follow
those for non-narrowing sqrt.

Tested as followed: natively with the full glibc testsuite for x86_64
(GCC 11, 7, 6) and x86 (GCC 11); with build-many-glibcs.py with GCC
11, 7 and 6; cross testing of math/ tests for powerpc64le, powerpc32
hard float, mips64 (all three ABIs, both hard and soft float).  The
different GCC versions are to cover the different cases in tgmath.h
and tgmath.h tests properly (GCC 6 has _Float* only as typedefs in
glibc headers, GCC 7 has proper _Float* support, GCC 8 adds
__builtin_tgmath).
2021-09-10 20:56:22 +00:00

136 lines
4.7 KiB
C

/* Alias macros for functions returning a narrower type.
Copyright (C) 2018-2021 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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
<https://www.gnu.org/licenses/>. */
#ifndef _MATH_NARROW_ALIAS_H
#define _MATH_NARROW_ALIAS_H 1
#include <bits/floatn.h>
#include <bits/long-double.h>
/* The following macros declare aliases for a narrowing function. The
sole argument is the base name of a family of functions, such as
"add". If any platform changes long double format after the
introduction of narrowing functions, in a way requiring symbol
versioning compatibility, additional variants of these macros will
be needed. */
#define libm_alias_float_double_main(func) \
weak_alias (__f ## func, f ## func) \
weak_alias (__f ## func, f32 ## func ## f64) \
weak_alias (__f ## func, f32 ## func ## f32x)
#ifdef NO_LONG_DOUBLE
# define libm_alias_float_double(func) \
libm_alias_float_double_main (func) \
weak_alias (__f ## func, f ## func ## l)
#else
# define libm_alias_float_double(func) \
libm_alias_float_double_main (func)
#endif
#define libm_alias_float32x_float64_main(func) \
weak_alias (__f32x ## func ## f64, f32x ## func ## f64)
#ifdef NO_LONG_DOUBLE
# define libm_alias_float32x_float64(func) \
libm_alias_float32x_float64_main (func) \
weak_alias (__f32x ## func ## f64, d ## func ## l)
#elif defined __LONG_DOUBLE_MATH_OPTIONAL
# define libm_alias_float32x_float64(func) \
libm_alias_float32x_float64_main (func) \
weak_alias (__f32x ## func ## f64, __nldbl_d ## func ## l)
#else
# define libm_alias_float32x_float64(func) \
libm_alias_float32x_float64_main (func)
#endif
#if __HAVE_FLOAT128 && !__HAVE_DISTINCT_FLOAT128
# define libm_alias_float_ldouble_f128(func) \
weak_alias (__f ## func ## l, f32 ## func ## f128)
# define libm_alias_double_ldouble_f128(func) \
weak_alias (__d ## func ## l, f32x ## func ## f128) \
weak_alias (__d ## func ## l, f64 ## func ## f128)
#else
# define libm_alias_float_ldouble_f128(func)
# define libm_alias_double_ldouble_f128(func)
#endif
#if __HAVE_FLOAT64X_LONG_DOUBLE
# define libm_alias_float_ldouble_f64x(func) \
weak_alias (__f ## func ## l, f32 ## func ## f64x)
# define libm_alias_double_ldouble_f64x(func) \
weak_alias (__d ## func ## l, f32x ## func ## f64x) \
weak_alias (__d ## func ## l, f64 ## func ## f64x)
#else
# define libm_alias_float_ldouble_f64x(func)
# define libm_alias_double_ldouble_f64x(func)
#endif
#define libm_alias_float_ldouble(func) \
weak_alias (__f ## func ## l, f ## func ## l) \
libm_alias_float_ldouble_f128 (func) \
libm_alias_float_ldouble_f64x (func)
#define libm_alias_double_ldouble(func) \
weak_alias (__d ## func ## l, d ## func ## l) \
libm_alias_double_ldouble_f128 (func) \
libm_alias_double_ldouble_f64x (func)
#define libm_alias_float64x_float128(func) \
weak_alias (__f64x ## func ## f128, f64x ## func ## f128)
#define libm_alias_float32_float128_main(func) \
weak_alias (__f32 ## func ## f128, f32 ## func ## f128)
#define libm_alias_float64_float128_main(func) \
weak_alias (__f64 ## func ## f128, f64 ## func ## f128) \
weak_alias (__f64 ## func ## f128, f32x ## func ## f128)
#include <math-narrow-alias-float128.h>
/* The following macros declare narrowing-named aliases for a
non-narrowing function. */
#define libm_alias_double_narrow_main(from, to) \
weak_alias (from, f32x ## to ## f64)
#ifdef NO_LONG_DOUBLE
# define libm_alias_double_narrow(from, to) \
libm_alias_double_narrow_main (from, to) \
weak_alias (from, d ## to ## l)
#else
# define libm_alias_double_narrow(from, to) \
libm_alias_double_narrow_main (from, to)
#endif
#if __HAVE_FLOAT64X_LONG_DOUBLE && __HAVE_FLOAT128 && !__HAVE_DISTINCT_FLOAT128
# define libm_alias_ldouble_narrow(from, to) \
weak_alias (from ## l, f64x ## to ## f128)
#else
# define libm_alias_ldouble_narrow(from, to)
#endif
#if __HAVE_DISTINCT_FLOAT128 && __HAVE_FLOAT64X && !__HAVE_FLOAT64X_LONG_DOUBLE
# define libm_alias_float128_narrow(from, to) \
weak_alias (from ## f128, f64x ## to ## f128)
#else
# define libm_alias_float128_narrow(from, to)
#endif
#endif /* math-narrow-alias.h. */