1  /* Square root of long double (ldbl-128) value, narrowing the result to
       2     double, using soft-fp.
       3     Copyright (C) 2021-2023 Free Software Foundation, Inc.
       4     This file is part of the GNU C Library.
       5  
       6     The GNU C Library is free software; you can redistribute it and/or
       7     modify it under the terms of the GNU Lesser General Public
       8     License as published by the Free Software Foundation; either
       9     version 2.1 of the License, or (at your option) any later version.
      10  
      11     The GNU C Library is distributed in the hope that it will be useful,
      12     but WITHOUT ANY WARRANTY; without even the implied warranty of
      13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      14     Lesser General Public License for more details.
      15  
      16     You should have received a copy of the GNU Lesser General Public
      17     License along with the GNU C Library; if not, see
      18     <https://www.gnu.org/licenses/>.  */
      19  
      20  #define f32xsqrtf64x __hide_f32xsqrtf64x
      21  #define f32xsqrtf128 __hide_f32xsqrtf128
      22  #define f64sqrtf64x __hide_f64sqrtf64x
      23  #define f64sqrtf128 __hide_f64sqrtf128
      24  #include <math.h>
      25  #undef f32xsqrtf64x
      26  #undef f32xsqrtf128
      27  #undef f64sqrtf64x
      28  #undef f64sqrtf128
      29  
      30  #include <math-narrow.h>
      31  #include <libc-diag.h>
      32  
      33  /* Some components of the result's significand and exponent are not
      34     set in cases where they are not used in packing, but the compiler
      35     does not see that they are set in all cases where they are used,
      36     resulting in warnings that they may be used uninitialized.  */
      37  DIAG_PUSH_NEEDS_COMMENT;
      38  DIAG_IGNORE_NEEDS_COMMENT (7, "-Wmaybe-uninitialized");
      39  #include <soft-fp.h>
      40  #include <double.h>
      41  #include <quad.h>
      42  
      43  double
      44  __dsqrtl (_Float128 x)
      45  {
      46    FP_DECL_EX;
      47    FP_DECL_Q (X);
      48    FP_DECL_Q (R);
      49    FP_DECL_D (RN);
      50    double ret;
      51  
      52    FP_INIT_ROUNDMODE;
      53    FP_UNPACK_Q (X, x);
      54    FP_SQRT_Q (R, X);
      55  #if _FP_W_TYPE_SIZE < 64
      56    FP_TRUNC_COOKED (D, Q, 2, 4, RN, R);
      57  #else
      58    FP_TRUNC_COOKED (D, Q, 1, 2, RN, R);
      59  #endif
      60    FP_PACK_D (ret, RN);
      61    FP_HANDLE_EXCEPTIONS;
      62    CHECK_NARROW_SQRT (ret, x);
      63    return ret;
      64  }
      65  DIAG_POP_NEEDS_COMMENT;
      66  
      67  libm_alias_double_ldouble (sqrt)