fs2ulong.c

来自「sdcc是为51等小型嵌入式cpu设计的c语言编译器支持数种不同类型的cpu」· C语言 代码 · 共 50 行

/*
** libgcc support for software floating point.
** Copyright (C) 1991 by Pipeline Associates, Inc.  All rights reserved.
** Permission is granted to do *anything* you want with this file,
** commercial or otherwise, provided this message remains intact.  So there!
** I would appreciate receiving any updates/patches/changes that anyone
** makes, and am willing to be the repository for said changes (am I
** making a big mistake?).
**
** Pat Wood
** Pipeline Associates, Inc.
** pipeline![e-mail] or
** sun!pipeline!phw or
** uunet!motown!pipeline!phw
*/

/*
** $Id: fs2ulong.c 3711 2005-03-31 16:25:17Z vrokas $
*/

/* (c)2000/2001: hacked a little by [e-mail] for sdcc */

#include <float.h>

union float_long
{
  float f;
  long l;
};

/* convert float to unsigned long */
unsigned long __fs2ulong (float a1) _FS_REENTRANT
{
  FS_STATIC volatile union float_long fl1;
  int exp;
  long l;
  
  fl1.f = a1;
  
  if (!fl1.l || SIGN(fl1.l))
    return (0);

  exp = EXP (fl1.l) - EXCESS - 24;
  l = MANT (fl1.l);
  
  l >>= -exp;

  return l;
}