1  /* Square root of double value, narrowing the result to float, using soft-fp.
       2     Copyright (C) 2021-2023 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 <libc-diag.h>
      29  /* R_f[01] are not set in cases where they are not used in packing,
      30     but the compiler does not see that they are set in all cases where
      31     they are used, resulting in warnings that they may be used
      32     uninitialized.  The location of the warning differs in different
      33     versions of GCC, it may be where R is defined using a macro or it
      34     may be where the macro is defined.  This happens only with -O1.  */
      35  DIAG_PUSH_NEEDS_COMMENT;
      36  DIAG_IGNORE_NEEDS_COMMENT (8, "-Wmaybe-uninitialized");
      37  #include <soft-fp.h>
      38  #include <single.h>
      39  #include <double.h>
      40  
      41  float
      42  __fsqrt (double x)
      43  {
      44    FP_DECL_EX;
      45    FP_DECL_D (X);
      46    FP_DECL_D (R);
      47    FP_DECL_S (RN);
      48    float ret;
      49  
      50    FP_INIT_ROUNDMODE;
      51    FP_UNPACK_D (X, x);
      52    FP_SQRT_D (R, X);
      53  #if _FP_W_TYPE_SIZE < _FP_FRACBITS_D
      54    FP_TRUNC_COOKED (S, D, 1, 2, RN, R);
      55  #else
      56    FP_TRUNC_COOKED (S, D, 1, 1, RN, R);
      57  #endif
      58    FP_PACK_S (ret, RN);
      59    FP_HANDLE_EXCEPTIONS;
      60    CHECK_NARROW_SQRT (ret, x);
      61    return ret;
      62  }
      63  DIAG_POP_NEEDS_COMMENT;
      64  
      65  libm_alias_float_double (sqrt)