glibc/sysdeps/ieee754/soft-fp/s_fsqrt.c

66 lines
2.0 KiB
C

/* Square root of double value, narrowing the result to float, using soft-fp.
Copyright (C) 2021-2024 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/>. */
#define f32sqrtf64 __hide_f32sqrtf64
#define f32sqrtf32x __hide_f32sqrtf32x
#define fsqrtl __hide_fsqrtl
#include <math.h>
#undef f32sqrtf64
#undef f32sqrtf32x
#undef fsqrtl
#include <math-narrow.h>
#include <libc-diag.h>
/* R_f[01] are not set in cases where they are not used in packing,
but the compiler does not see that they are set in all cases where
they are used, resulting in warnings that they may be used
uninitialized. The location of the warning differs in different
versions of GCC, it may be where R is defined using a macro or it
may be where the macro is defined. This happens only with -O1. */
DIAG_PUSH_NEEDS_COMMENT;
DIAG_IGNORE_NEEDS_COMMENT (8, "-Wmaybe-uninitialized");
#include <soft-fp.h>
#include <single.h>
#include <double.h>
float
__fsqrt (double x)
{
FP_DECL_EX;
FP_DECL_D (X);
FP_DECL_D (R);
FP_DECL_S (RN);
float ret;
FP_INIT_ROUNDMODE;
FP_UNPACK_D (X, x);
FP_SQRT_D (R, X);
#if _FP_W_TYPE_SIZE < _FP_FRACBITS_D
FP_TRUNC_COOKED (S, D, 1, 2, RN, R);
#else
FP_TRUNC_COOKED (S, D, 1, 1, RN, R);
#endif
FP_PACK_S (ret, RN);
FP_HANDLE_EXCEPTIONS;
CHECK_NARROW_SQRT (ret, x);
return ret;
}
DIAG_POP_NEEDS_COMMENT;
libm_alias_float_double (sqrt)