1  /* rintf().  RISC-V version.
       2     Copyright (C) 2017-2023 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 NO_MATH_REDIRECT
      20  #include <math.h>
      21  #include <stdbool.h>
      22  #include <libm-alias-float.h>
      23  #include <stdint.h>
      24  
      25  float
      26  __rintf (float x)
      27  {
      28    bool nan;
      29    float mag;
      30  
      31    nan = isnan (x);
      32    mag = fabsf (x);
      33  
      34    if (nan)
      35      return x + x;
      36  
      37    if (mag < (1 << __FLT_MANT_DIG__))
      38      {
      39        int32_t i;
      40        float new_x;
      41  
      42        asm ("fcvt.w.s %0, %1" : "=r" (i) : "f" (x));
      43        asm ("fcvt.s.w %0, %1" : "=f" (new_x) : "r" (i));
      44  
      45        /* rint(-0) == -0, and in general we'll always have the same
      46  	 sign as our input.  */
      47        x = copysignf (new_x, x);
      48      }
      49  
      50    return x;
      51  }
      52  
      53  libm_alias_float (__rint, rint)