kc3-lang/SDL/src/libm/s_floor.c

• Show log

  Commit

• Hash : f848adff
  Author :
  Date : 2013-11-29T10:06:08
  

  Improve Android pause/resume behavior.

Download

• src/libm/s_floor.c

• /* @(#)s_floor.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.
   * ====================================================
   */
  
  #if defined(LIBM_SCCS) && !defined(lint)
  static const char rcsid[] =
      "$NetBSD: s_floor.c,v 1.8 1995/05/10 20:47:20 jtc Exp $";
  #endif
  
  /*
   * floor(x)
   * Return x rounded toward -inf to integral value
   * Method:
   *	Bit twiddling.
   * Exception:
   *	Inexact flag raised if x not equal to floor(x).
   */
  
  #include "math_libm.h"
  #include "math_private.h"
  
  #ifdef __STDC__
  static const double huge_val = 1.0e300;
  #else
  static double huge_val = 1.0e300;
  #endif
  
  libm_hidden_proto(floor)
  #ifdef __STDC__
       double floor(double x)
  #else
       double floor(x)
       double x;
  #endif
  {
      int32_t i0, i1, j0;
      u_int32_t i, j;
      EXTRACT_WORDS(i0, i1, x);
      j0 = ((i0 >> 20) & 0x7ff) - 0x3ff;
      if (j0 < 20) {
          if (j0 < 0) {           /* raise inexact if x != 0 */
              if (huge_val + x > 0.0) {       /* return 0*sign(x) if |x|<1 */
                  if (i0 >= 0) {
                      i0 = i1 = 0;
                  } else if (((i0 & 0x7fffffff) | i1) != 0) {
                      i0 = 0xbff00000;
                      i1 = 0;
                  }
              }
          } else {
              i = (0x000fffff) >> j0;
              if (((i0 & i) | i1) == 0)
                  return x;       /* x is integral */
              if (huge_val + x > 0.0) {       /* raise inexact flag */
                  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 = ((u_int32_t) (0xffffffff)) >> (j0 - 20);
          if ((i1 & i) == 0)
              return x;           /* x is integral */
          if (huge_val + x > 0.0) {   /* raise inexact flag */
              if (i0 < 0) {
                  if (j0 == 20)
                      i0 += 1;
                  else {
                      j = i1 + (1 << (52 - j0));
                      if (j < (u_int32_t) i1)
                          i0 += 1;        /* got a carry */
                      i1 = j;
                  }
              }
              i1 &= (~i);
          }
      }
      INSERT_WORDS(x, i0, i1);
      return x;
  }
  
  libm_hidden_def(floor)
  

Download