text: /* @(#)s_ceil.c 5.1 93/09/24 */
  /*
   * ====================================================
   * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
   *
   * Developed at SunPro, a Sun Microsystems, Inc. business.
   * Permission to use, copy, modify, and distribute this
   * software is freely granted, provided that this notice
   * is preserved.
   * ====================================================
   */
  
  /*
   * ceil(x)
   * Return x rounded toward -inf to integral value
   * Method:
   *	Bit twiddling.
   */
  
  #define NO_MATH_REDIRECT
  #include <libm-alias-double.h>
  #include <math.h>
  #include <math_private.h>
  
  double __ceil(double x)
  {
      int32_t i0, i1, j0;
      uint32_t i, j;
      EXTRACT_WORDS(i0, i1, x);
      j0 = ((i0 >> 20) & 0x7ff) - 0x3ff;
      if (j0 < 20)
      {
          if (j0 < 0)
          {
              /* return 0*sign(x) if |x|<1 */
              if (i0 < 0)
              {
                  i0 = 0x80000000;
                  i1 = 0;
              }
              else if ((i0 | i1) != 0)
              {
                  i0 = 0x3ff00000;
                  i1 = 0;
              }
          }
          else
          {
              i = (0x000fffff) >> j0;
              if (((i0 & i) | i1) == 0)
                  return x; /* x is integral */
              if (i0 > 0)
                  i0 += (0x00100000) >> j0;
              i0 &= (~i);
              i1 = 0;
          }
      }
      else if (j0 > 51)
      {
          if (j0 == 0x400)
              return x + x; /* inf or NaN */
          else
              return x; /* x is integral */
      }
      else
      {
          i = ((uint32_t)(0xffffffff)) >> (j0 - 20);
          if ((i1 & i) == 0)
              return x; /* x is integral */
          if (i0 > 0)
          {
              if (j0 == 20)
                  i0 += 1;
              else
              {
                  j = i1 + (1 << (52 - j0));
                  if (j < i1)
                      i0 += 1; /* got a carry */
                  i1 = j;
              }
          }
          i1 &= (~i);
      }
      INSERT_WORDS(x, i0, i1);
      return x;
  }
  #ifndef __ceil
  libm_alias_double(__ceil, ceil)
  #endif
  