sysdeps/ieee754/soft-fp/s_fsqrt.c

   1 /* Square root of double value, narrowing the result to float, using soft-fp.
   2    Copyright (C) 2021 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #define f32sqrtf64 __hide_f32sqrtf64
  20 #define f32sqrtf32x __hide_f32sqrtf32x
  21 #define fsqrtl __hide_fsqrtl
  22 #include <math.h>
  23 #undef f32sqrtf64
  24 #undef f32sqrtf32x
  25 #undef fsqrtl
  26
  27 #include <math-narrow.h>
  28 #include <soft-fp.h>
  29 #include <single.h>
  30 #include <double.h>
  31
  32 float
  33 __fsqrt (double x)
  34 {
  35   FP_DECL_EX;
  36   FP_DECL_D (X);
  37   FP_DECL_D (R);
  38   FP_DECL_S (RN);
  39   float ret;
  40
  41   FP_INIT_ROUNDMODE;
  42   FP_UNPACK_D (X, x);
  43   FP_SQRT_D (R, X);
  44 #if _FP_W_TYPE_SIZE < _FP_FRACBITS_D
  45   FP_TRUNC_COOKED (S, D, 1, 2, RN, R);
  46 #else
  47   FP_TRUNC_COOKED (S, D, 1, 1, RN, R);
  48 #endif
  49   FP_PACK_S (ret, RN);
  50   FP_HANDLE_EXCEPTIONS;
  51   CHECK_NARROW_SQRT (ret, x);
  52   return ret;
  53 }
  54 libm_alias_float_double (sqrt)