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  1. /*-------------------------------------------------------------------------
  2.    _ulong2fs.c - Floating point library in optimized assembly for 8051
  3.  
  4.    Copyright (c) 2004, Paul Stoffregen, paul@pjrc.com
  5.  
  6.    This library is free software; you can redistribute it and/or modify it
  7.    under the terms of the GNU General Public License as published by the
  8.    Free Software Foundation; either version 2, or (at your option) any
  9.    later version.
  10.  
  11.    This library is distributed in the hope that it will be useful,
  12.    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13.    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14.    GNU General Public License for more details.
  15.  
  16.    You should have received a copy of the GNU General Public License
  17.    along with this library; see the file COPYING. If not, write to the
  18.    Free Software Foundation, 51 Franklin Street, Fifth Floor, Boston,
  19.    MA 02110-1301, USA.
  20.  
  21.    As a special exception, if you link this library with other files,
  22.    some of which are compiled with SDCC, to produce an executable,
  23.    this library does not by itself cause the resulting executable to
  24.    be covered by the GNU General Public License. This exception does
  25.    not however invalidate any other reasons why the executable file
  26.    might be covered by the GNU General Public License.
  27. -------------------------------------------------------------------------*/
  28.  
  29.  
  30. #define __SDCC_FLOAT_LIB
  31. #include <float.h>
  32.  
  33.  
  34. #ifdef FLOAT_ASM_MCS51
  35.  
  36. // float long __ulong2fs (float x)
  37. static void dummy(void) __naked
  38. {
  39.         __asm
  40.         .globl  ___ulong2fs
  41. ___ulong2fs:
  42.         mov     r4, a
  43.         mov     r3, b
  44.         mov     r2, dph
  45.         mov     r1, dpl
  46.         mov     a, #158
  47.         .globl  ulong2fs_doit
  48. ulong2fs_doit:
  49.         clr     sign_a
  50. long2fs_doit:
  51.         mov     exp_a, a
  52.         lcall   fs_normalize_a
  53.         ljmp    fs_round_and_return
  54.         __endasm;
  55. }
  56.  
  57. #else
  58.  
  59. /*
  60. ** libgcc support for software floating point.
  61. ** Copyright (C) 1991 by Pipeline Associates, Inc.  All rights reserved.
  62. ** Permission is granted to do *anything* you want with this file,
  63. ** commercial or otherwise, provided this message remains intact.  So there!
  64. ** I would appreciate receiving any updates/patches/changes that anyone
  65. ** makes, and am willing to be the repository for said changes (am I
  66. ** making a big mistake?).
  67. **
  68. ** Pat Wood
  69. ** Pipeline Associates, Inc.
  70. ** pipeline!phw@motown.com or
  71. ** sun!pipeline!phw or
  72. ** uunet!motown!pipeline!phw
  73. */
  74.  
  75. /* (c)2000/2001: hacked a little by johan.knol@iduna.nl for sdcc */
  76.  
  77. union float_long
  78.   {
  79.     float f;
  80.     long l;
  81.   };
  82.  
  83. float __ulong2fs (unsigned long a )
  84. {
  85.   unsigned char exp = 24 + EXCESS;
  86.   volatile union float_long fl;
  87.  
  88.   if (!a)
  89.     {
  90.       return 0.0;
  91.     }
  92.  
  93.   while (a < HIDDEN)
  94.     {
  95.       a <<= 1;
  96.       exp--;
  97.     }
  98.  
  99.   while (a & NORM)
  100.     {
  101.       // we lose accuracy here
  102.       if (a & 1)
  103.         a += 2;
  104.       a >>= 1;
  105.       exp++;
  106.     }
  107.  
  108.   a &= ~HIDDEN ;
  109.   /* pack up and go home */
  110.   fl.l = PACK(0,(unsigned long)exp, a);
  111.  
  112.   return (fl.f);
  113. }
  114.  
  115. #endif
  116.