glibc/sysdeps/ieee754/ldbl-96/s_dsubl.c
Joseph Myers 8d3f9e85cf Add narrowing subtract functions.
This patch adds the narrowing subtract functions from TS 18661-1 to
glibc's libm: fsub, fsubl, dsubl, f32subf64, f32subf32x, f32xsubf64
for all configurations; f32subf64x, f32subf128, f64subf64x,
f64subf128, f32xsubf64x, f32xsubf128, f64xsubf128 for configurations
with _Float64x and _Float128; __nldbl_dsubl for ldbl-opt.

The changes are essentially the same as for the narrowing add
functions, so the description of those generally applies to this patch
as well.

Tested for x86_64, x86, mips64 (all three ABIs, both hard and soft
float) and powerpc, and with build-many-glibcs.py.

	* math/Makefile (libm-narrow-fns): Add sub.
	(libm-test-funcs-narrow): Likewise.
	* math/Versions (GLIBC_2.28): Add narrowing subtract functions.
	* math/bits/mathcalls-narrow.h (sub): Use __MATHCALL_NARROW.
	* math/gen-auto-libm-tests.c (test_functions): Add sub.
	* math/math-narrow.h (CHECK_NARROW_SUB): New macro.
	(NARROW_SUB_ROUND_TO_ODD): Likewise.
	(NARROW_SUB_TRIVIAL): Likewise.
	* sysdeps/ieee754/float128/float128_private.h (__fsubl): New
	macro.
	(__dsubl): Likewise.
	* sysdeps/ieee754/ldbl-opt/Makefile (libnldbl-calls): Add fsub and
	dsub.
	(CFLAGS-nldbl-dsub.c): New variable.
	(CFLAGS-nldbl-fsub.c): Likewise.
	* sysdeps/ieee754/ldbl-opt/Versions (GLIBC_2.28): Add
	__nldbl_dsubl.
	* sysdeps/ieee754/ldbl-opt/nldbl-compat.h (__nldbl_dsubl): New
	prototype.
	* manual/arith.texi (Misc FP Arithmetic): Document fsub, fsubl,
	dsubl, fMsubfN, fMsubfNx, fMxsubfN and fMxsubfNx.
	* math/auto-libm-test-in: Add tests of sub.
	* math/auto-libm-test-out-narrow-sub: New generated file.
	* math/libm-test-narrow-sub.inc: New file.
	* sysdeps/i386/fpu/s_f32xsubf64.c: Likewise.
	* sysdeps/ieee754/dbl-64/s_f32xsubf64.c: Likewise.
	* sysdeps/ieee754/dbl-64/s_fsub.c: Likewise.
	* sysdeps/ieee754/float128/s_f32subf128.c: Likewise.
	* sysdeps/ieee754/float128/s_f64subf128.c: Likewise.
	* sysdeps/ieee754/float128/s_f64xsubf128.c: Likewise.
	* sysdeps/ieee754/ldbl-128/s_dsubl.c: Likewise.
	* sysdeps/ieee754/ldbl-128/s_f64xsubf128.c: Likewise.
	* sysdeps/ieee754/ldbl-128/s_fsubl.c: Likewise.
	* sysdeps/ieee754/ldbl-128ibm/s_dsubl.c: Likewise.
	* sysdeps/ieee754/ldbl-128ibm/s_fsubl.c: Likewise.
	* sysdeps/ieee754/ldbl-96/s_dsubl.c: Likewise.
	* sysdeps/ieee754/ldbl-96/s_fsubl.c: Likewise.
	* sysdeps/ieee754/ldbl-opt/nldbl-dsub.c: Likewise.
	* sysdeps/ieee754/ldbl-opt/nldbl-fsub.c: Likewise.
	* sysdeps/ieee754/soft-fp/s_dsubl.c: Likewise.
	* sysdeps/ieee754/soft-fp/s_fsub.c: Likewise.
	* sysdeps/ieee754/soft-fp/s_fsubl.c: Likewise.
	* sysdeps/powerpc/fpu/libm-test-ulps: Update.
	* sysdeps/mach/hurd/i386/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/aarch64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/alpha/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/arm/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/hppa/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/i386/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/ia64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/m68k/coldfire/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/m68k/m680x0/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/microblaze/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips32/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/nios2/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/riscv/rv64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-32/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/sh/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/tile/tilegx32/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/tile/tilegx64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.
2018-03-20 00:34:52 +00:00

34 lines
1.2 KiB
C

/* Subtract long double (ldbl-96) values, narrowing the result to double.
Copyright (C) 2018 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
<http://www.gnu.org/licenses/>. */
#define f32xsubf64x __hide_f32xsubf64x
#define f64subf64x __hide_f64subf64x
#include <math.h>
#undef f32xsubf64x
#undef f64subf64x
#include <math-narrow.h>
double
__dsubl (long double x, long double y)
{
NARROW_SUB_ROUND_TO_ODD (x, y, double, union ieee854_long_double, l,
mantissa1);
}
libm_alias_double_ldouble (sub)