compiler/stdc/math/s_roundl.c

   1 /*-
   2  * Copyright (c) 2003, Steven G. Kargl
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice unmodified, this list of conditions, and the following
  10  *    disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  */
  26
  27 __FBSDID("$FreeBSD: src/lib/msun/src/s_roundl.c,v 1.2 2005/12/02 13:45:06 bde Exp $");
  28
  29 #include <float.h>
  30 #if defined(__x86_64__)
  31 #include "x86_64/ieeefp.h"
  32 #elif defined(__i386__)
  33 #include "i386/ieeefp.h"
  34 #endif
  35
  36 #include "fpmath.h"
  37 #include "math.h"
  38 #include "math_private.h"
  39
  40 long double
  41 roundl(long double x)
  42 {
  43         long double t;
  44         uint16_t hx;
  45
  46         GET_LDBL_EXPSIGN(hx, x);
  47         if ((hx & 0x7fff) == 0x7fff)
  48                 return (x + x);
  49
  50         ENTERI();
  51
  52         if (!(hx & 0x8000)) {
  53                 t = floorl(x);
  54                 if (t - x <= -0.5L)
  55                         t += 1;
  56                 RETURNI(t);
  57         } else {
  58                 t = floorl(-x);
  59                 if (t + x <= -0.5L)
  60                         t += 1;
  61                 RETURNI(-t);
  62         }
  63 }