libchill/powerset.h

   1 /* Common macros for POWERSET runtime actions for CHILL.
   2    Copyright (C) 1992,1993 Free Software Foundation, Inc.
   3    Author: Wilfried Moser, et al
   4
   5 This file is part of GNU CC.
   6
   7 GNU CC is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2, or (at your option)
  10 any later version.
  11
  12 GNU CC is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GNU CC; see the file COPYING.  If not, write to
  19 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
  20
  21 #ifndef _POWERSET_H
  22 #define _POWERSET_H
  23
  24 #define USE_CHARS
  25
  26 #ifdef USE_CHARS
  27
  28 #define SET_WORD unsigned char
  29 #define SET_CHAR  unsigned char
  30 #define SET_SHORT unsigned char
  31
  32 #else
  33
  34 #ifndef SET_WORD
  35 #define SET_WORD unsigned int
  36 #endif
  37 #define SET_CHAR  unsigned char
  38 #define SET_SHORT unsigned short
  39 #endif
  40
  41 #define SET_WORD_SIZE (sizeof (char) * sizeof (SET_WORD))
  42 #define SET_SHORT_SIZE (sizeof (char) * sizeof (SET_SHORT))
  43 #define SET_CHAR_SIZE sizeof (char)
  44
  45 /* Powersets and bit strings are stored as arrays of SET_WORD.
  46    if they are a word or longer.  Powersets and bit strings whic
  47    fit in a byte or short are stored that way by the compiler.
  48
  49    The order of the bits follows native bit order:
  50    If BITS_BIG_ENDIAN, bit 0 is the most significant bit (i.e. 0x80..00);
  51    otherwise, bit 0 is the least significant bit (i.e. 0x1).
  52
  53    MASK_UNUSED_BITS masks out unused bits in powersets and bitstrings.
  54    GET_BIT_IN_WORD(W,B) yields 1 (or 0) if the B'th bit if W is set (cleared).
  55 */
  56
  57 #if BITS_BIG_ENDIAN
  58 #define GET_BIT_IN_WORD(w,b) (((w) >> (SET_WORD_SIZE - 1 - (b))) & 1)
  59 #define GET_BIT_IN_SHORT(w,b) (((w) >> (SET_SHORT_SIZE - 1 - (b))) & 1)
  60 #define GET_BIT_IN_CHAR(w,b) (((w) >> (SET_CHAR_SIZE - 1 - (b))) & 1)
  61
  62 #define SET_BIT_IN_WORD(w,b) ((w) |= 1 << ((SET_WORD_SIZE) - 1 - (b)))
  63 #define SET_BIT_IN_SHORT(w,b) ((w) |= 1 << ((SET_SHORT_SIZE) - 1 - (b)))
  64 #define SET_BIT_IN_CHAR(w,b) ((w) |= 1 << ((SET_CHAR_SIZE) - 1 - (b)))
  65
  66 #define CLEAR_BIT_IN_WORD(w,b) ((w) &= ~(1 << ((SET_WORD_SIZE) - 1 - (b))))
  67 #define CLEAR_BIT_IN_SHORT(w,b) ((w) &= ~(1 << ((SET_SHORT_SIZE) - 1 - (b))))
  68 #define CLEAR_BIT_IN_CHAR(w,b) ((w) &= ~(1 << ((SET_CHAR_SIZE) - 1 - (b))))
  69 #define MASK_UNUSED_WORD_BITS(p,b)                 \
  70 { if (b) *(p) &= (~0) << (SET_WORD_SIZE - (b)); }
  71 #define MASK_UNUSED_SHORT_BITS(p,b)                \
  72 { if (b) *(p) &= (~0) << (SET_SHORT_SIZE - (b)); }
  73 #define MASK_UNUSED_CHAR_BITS(p,b)                 \
  74 { if (b) *(p) &= (~0) << (SET_CHAR_SIZE - (b)); }
  75
  76 #else /* !BITS_BIG_ENDIAN */
  77
  78 #define GET_BIT_IN_WORD(w,b) (((w) >> (b)) & 1)
  79 #define GET_BIT_IN_SHORT(w,b) GET_BIT_IN_WORD(w,b)
  80 #define GET_BIT_IN_CHAR(w,b) GET_BIT_IN_WORD(w,b)
  81
  82 #define SET_BIT_IN_WORD(w,b) ((w) |= 1 << (b))
  83 #define SET_BIT_IN_SHORT(w,b) SET_BIT_IN_WORD(w,b)
  84 #define SET_BIT_IN_CHAR(w,b) SET_BIT_IN_WORD(w,b)
  85
  86 #define CLEAR_BIT_IN_WORD(w,b) ((w) &= ~(1 << (b)))
  87 #define CLEAR_BIT_IN_SHORT(w,b) CLEAR_BIT_IN_WORD(w,b)
  88 #define CLEAR_BIT_IN_CHAR(w,b) CLEAR_BIT_IN_WORD(w,b)
  89
  90 #define MASK_UNUSED_WORD_BITS(p,b)  \
  91 { if (b) *(p) &= ~((~0) << (b)); }
  92 #define MASK_UNUSED_SHORT_BITS(p,b) MASK_UNUSED_WORD_BITS(p,b)
  93 #define MASK_UNUSED_CHAR_BITS(p,b) MASK_UNUSED_WORD_BITS(p,b)
  94
  95 #endif
  96
  97
  98 /* Number of words needed for a bitstring/powerset of size BITLENGTH.
  99    This definition handles the (BITLENGTH==0) by yielding 0. */
 100
 101 #define BITS_TO_WORDS(BITLENGTH) \
 102   (((BITLENGTH) + (SET_WORD_SIZE-1)) / SET_WORD_SIZE)
 103 #define BITS_TO_CHARS(BITLENGTH) \
 104   (((BITLENGTH) + (SET_CHAR_SIZE-1)) / SET_CHAR_SIZE)
 105
 106 #endif