[storin] / bits.h

/* -*-c-*-
 *
 * $Id: bits.h,v 1.1 2000/05/21 11:28:30 mdw Exp $
 *
 * Portable bit-level manipulation macros
 *
 * (c) 1998 Straylight/Edgeware
 * (c) 2000 Mark Wooding
 */

/*----- Licensing notice --------------------------------------------------* 
 *
 * Copyright (c) 2000 Mark Wooding
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 * 
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 
 * 2, Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 
 * 3. The name of the authors may not be used to endorse or promote
 *    products derived from this software without specific prior written
 *    permission.
 * 
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
 * NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 * 
 * Instead of accepting the above terms, you may redistribute and/or modify
 * this software under the terms of either the GNU General Public License,
 * or the GNU Library General Public License, published by the Free
 * Software Foundation; either version 2 of the License, or (at your
 * option) any later version.
 */

/*----- Revision history --------------------------------------------------* 
 *
 * $Log: bits.h,v $
 * Revision 1.1  2000/05/21 11:28:30  mdw
 * Initial check-in.
 *
 * --- Past lives (mLib) --- *
 *
 * Revision 1.4  1999/12/10 23:42:04  mdw
 * Change header file guard names.
 *
 * Revision 1.3  1999/06/20 23:31:52  mdw
 * More portability enhancements.
 *
 * Revision 1.2  1999/06/17 00:12:46  mdw
 * Improve portability for shift and rotate macros.
 *
 * Revision 1.1  1999/06/01 09:46:19  mdw
 * New addition: bit manipulation macros.
 */

#ifndef BITS_H
#define BITS_H

#ifdef __cplusplus
  extern "C" {
#endif

/*----- Header files ------------------------------------------------------*/

#include <limits.h>
#include <stddef.h>

/*----- Decide on some types ----------------------------------------------*/

/* --- Decide on a 32-bit type --- *
 *
 * I want a type which is capable of expressing 32-bit numbers.  Because some
 * implementations have 64-bit @long@s (infinitely preferable to the abortion
 * that is @long long@), using @unsigned long@ regardless is wasteful.  So,
 * if @int@ appears to be good enough, then I'll go with that.
 */

#if UINT_MAX >= 0xffffffffu
  typedef unsigned int uint32;
#else
  typedef unsigned long uint32;
#endif

/* --- Decide on a 24-bit type --- */

#if UINT_MAX >= 0x00ffffffu
  typedef unsigned int uint24;
#else
  typedef unsigned long uint24;
#endif

/* --- Decide on 16-bit and 8-bit types --- *
 *
 * This is more for brevity than anything else.
 */

typedef unsigned short uint16;
typedef unsigned char octet;

/* --- WARNING! --- *
 *
 * Never lose sight of the fact that the above types may be wider than the
 * names suggest.  Some architectures have 32-bit @short@s for example.
 */

/*----- Macros ------------------------------------------------------------*/

/* --- Useful masks --- */

#define MASK8 0xffu
#define MASK16 0xffffu
#define MASK24 0xffffffu
#define MASK32 0xffffffffu

/* --- Type coercions --- */

#define U8(x) ((octet)((x) & MASK8))
#define U16(x) ((uint16)((x) & MASK16))
#define U24(x) ((uint24)((x) & MASK24))
#define U32(x) ((uint32)((x) & MASK32))

/* --- Safe shifting macros --- */

#define LSL8(v, s) U8(U8(v) << ((s) & 7u))
#define LSR8(v, s) U8(U8(v) >> ((s) & 7u))
#define LSL16(v, s) U16(U16(v) << ((s) & 15u))
#define LSR16(v, s) U16(U16(v) >> ((s) & 15u))
#define LSL24(v, s) U24(U24(v) << ((s) % 24u))
#define LSR24(v, s) U24(U24(v) >> ((s) % 24u))
#define LSL32(v, s) U32(U32(v) << ((s) & 31u))
#define LSR32(v, s) U32(U32(v) >> ((s) & 31u))

/* --- Rotation macros --- */

#define ROL8(v, s) (LSL8((v), (s)) | (LSR8((v), 8u - (s))))
#define ROR8(v, s) (LSR8((v), (s)) | (LSL8((v), 8u - (s))))
#define ROL16(v, s) (LSL16((v), (s)) | (LSR16((v), 16u - (s))))
#define ROR16(v, s) (LSR16((v), (s)) | (LSL16((v), 16u - (s))))
#define ROL24(v, s) (LSL24((v), (s)) | (LSR24((v), 24u - (s))))
#define ROR24(v, s) (LSR24((v), (s)) | (LSL24((v), 24u - (s))))
#define ROL32(v, s) (LSL32((v), (s)) | (LSR32((v), 32u - (s))))
#define ROR32(v, s) (LSR32((v), (s)) | (LSL32((v), 32u - (s))))

/* --- Storage and retrieval --- */

#define GETBYTE(p, o) (((octet *)(p))[o] & MASK8)
#define PUTBYTE(p, o, v) (((octet *)(p))[o] = U8((v)))

#define LOAD8(p) (GETBYTE((p), 0))
#define STORE8(p, v) (PUTBYTE((p), 0, (v)))

#define LOAD16_B(p)							\
  (((uint16)GETBYTE((p), 0) << 8) |					\
   ((uint16)GETBYTE((p), 1) << 0))
#define LOAD16_L(p)							\
  (((uint16)GETBYTE((p), 0) << 0) |					\
   ((uint16)GETBYTE((p), 1) << 8))
#define LOAD16(p) LOAD16_B((p))

#define STORE16_B(p, v)							\
  (PUTBYTE((p), 0, (uint16)(v) >> 8),					\
   PUTBYTE((p), 1, (uint16)(v) >> 0))
#define STORE16_L(p, v)							\
  (PUTBYTE((p), 0, (uint16)(v) >> 0),					\
   PUTBYTE((p), 1, (uint16)(v) >> 8))
#define STORE16(p, v) STORE16_B((p), (v))

#define LOAD24_B(p)							\
  (((uint24)GETBYTE((p), 0) << 16) |					\
   ((uint24)GETBYTE((p), 1) <<  8) |					\
   ((uint24)GETBYTE((p), 2) <<  0))
#define LOAD24_L(p)							\
  (((uint24)GETBYTE((p), 0) <<  0) |					\
   ((uint24)GETBYTE((p), 1) <<  8) |					\
   ((uint24)GETBYTE((p), 2) << 16))
#define LOAD24(p) LOAD24_B((p))

#define STORE24_B(p, v)							\
  (PUTBYTE((p), 0, (uint24)(v) >> 16),					\
   PUTBYTE((p), 1, (uint24)(v) >>  8),					\
   PUTBYTE((p), 2, (uint24)(v) >>  0))
#define STORE24_L(p, v)							\
  (PUTBYTE((p), 0, (uint24)(v) >>  0),					\
   PUTBYTE((p), 1, (uint24)(v) >>  8),					\
   PUTBYTE((p), 2, (uint24)(v) >> 16))
#define STORE24(p, v) STORE24_B((p), (v))

#define LOAD32_B(p)							\
  (((uint32)GETBYTE((p), 0) << 24) |					\
   ((uint32)GETBYTE((p), 1) << 16) |					\
   ((uint32)GETBYTE((p), 2) <<  8) |					\
   ((uint32)GETBYTE((p), 3) <<  0))
#define LOAD32_L(p)							\
  (((uint32)GETBYTE((p), 0) <<  0) |					\
   ((uint32)GETBYTE((p), 1) <<  8) |					\
   ((uint32)GETBYTE((p), 2) << 16) |					\
   ((uint32)GETBYTE((p), 3) << 24))
#define LOAD32(p) LOAD32_B((p))

#define STORE32_B(p, v)							\
  (PUTBYTE((p), 0, (uint32)(v) >> 24),					\
   PUTBYTE((p), 1, (uint32)(v) >> 16),					\
   PUTBYTE((p), 2, (uint32)(v) >>  8),					\
   PUTBYTE((p), 3, (uint32)(v) >>  0))
#define STORE32_L(p, v)							\
  (PUTBYTE((p), 0, (uint32)(v) >>  0),					\
   PUTBYTE((p), 1, (uint32)(v) >>  8),					\
   PUTBYTE((p), 2, (uint32)(v) >> 16),					\
   PUTBYTE((p), 3, (uint32)(v) >> 24))
#define STORE32(p, v) STORE32_B((p), (v))

/*----- That's all, folks -------------------------------------------------*/

#ifdef __cplusplus
  }
#endif

#endif
Commit	Line	Data
e6e0e332 MW	1	/* --c--
	2	*
	3	* $Id: bits.h,v 1.1 2000/05/21 11:28:30 mdw Exp $
	4	*
	5	* Portable bit-level manipulation macros
	6	*
	7	* (c) 1998 Straylight/Edgeware
	8	* (c) 2000 Mark Wooding
	9	*/
	10
	11	/----- Licensing notice --------------------------------------------------
	12	*
	13	* Copyright (c) 2000 Mark Wooding
	14	* All rights reserved.
	15	*
	16	* Redistribution and use in source and binary forms, with or without
	17	* modification, are permitted provided that the following conditions are
	18	* met:
	19	*
	20	* 1. Redistributions of source code must retain the above copyright
	21	* notice, this list of conditions and the following disclaimer.
	22	*
	23	* 2, Redistributions in binary form must reproduce the above copyright
	24	* notice, this list of conditions and the following disclaimer in the
	25	* documentation and/or other materials provided with the distribution.
	26	*
	27	* 3. The name of the authors may not be used to endorse or promote
	28	* products derived from this software without specific prior written
	29	* permission.
	30	*
	31	* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
	32	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
	33	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
	34	* NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
	35	* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
	36	* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
	37	* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	38	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
	39	* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
	40	* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
	41	* POSSIBILITY OF SUCH DAMAGE.
	42	*
	43	* Instead of accepting the above terms, you may redistribute and/or modify
	44	* this software under the terms of either the GNU General Public License,
	45	* or the GNU Library General Public License, published by the Free
	46	* Software Foundation; either version 2 of the License, or (at your
	47	* option) any later version.
	48	*/
	49
	50	/----- Revision history --------------------------------------------------
	51	*
	52	* $Log: bits.h,v $
	53	* Revision 1.1 2000/05/21 11:28:30 mdw
	54	* Initial check-in.
	55	*
	56	* --- Past lives (mLib) --- *
	57	*
	58	* Revision 1.4 1999/12/10 23:42:04 mdw
	59	* Change header file guard names.
	60	*
	61	* Revision 1.3 1999/06/20 23:31:52 mdw
	62	* More portability enhancements.
	63	*
	64	* Revision 1.2 1999/06/17 00:12:46 mdw
65	* Improve portability for shift and rotate macros.
66	*
67	* Revision 1.1 1999/06/01 09:46:19 mdw
68	* New addition: bit manipulation macros.
69	*/
70
71	#ifndef BITS_H
72	#define BITS_H
73
74	#ifdef __cplusplus
75	extern "C" {
76	#endif
77
78	/----- Header files ------------------------------------------------------/
79
80	#include <limits.h>
81	#include <stddef.h>
82
83	/----- Decide on some types ----------------------------------------------/
84
85	/* --- Decide on a 32-bit type --- *
86	*
87	* I want a type which is capable of expressing 32-bit numbers. Because some
88	* implementations have 64-bit @long@s (infinitely preferable to the abortion
89	* that is @long long@), using @unsigned long@ regardless is wasteful. So,
90	* if @int@ appears to be good enough, then I'll go with that.
91	*/
92
93	#if UINT_MAX >= 0xffffffffu
94	typedef unsigned int uint32;
95	#else
96	typedef unsigned long uint32;
97	#endif
98
99	/* --- Decide on a 24-bit type --- */
100
101	#if UINT_MAX >= 0x00ffffffu
102	typedef unsigned int uint24;
103	#else
104	typedef unsigned long uint24;
105	#endif
106
107	/* --- Decide on 16-bit and 8-bit types --- *
108	*
109	* This is more for brevity than anything else.
110	*/
111
112	typedef unsigned short uint16;
113	typedef unsigned char octet;
114
115	/* --- WARNING! --- *
116	*
117	* Never lose sight of the fact that the above types may be wider than the
118	* names suggest. Some architectures have 32-bit @short@s for example.
119	*/
120
121	/----- Macros ------------------------------------------------------------/
122
123	/* --- Useful masks --- */
124
125	#define MASK8 0xffu
126	#define MASK16 0xffffu
127	#define MASK24 0xffffffu
128	#define MASK32 0xffffffffu
129
130	/* --- Type coercions --- */
131
132	#define U8(x) ((octet)((x) & MASK8))
133	#define U16(x) ((uint16)((x) & MASK16))
134	#define U24(x) ((uint24)((x) & MASK24))
135	#define U32(x) ((uint32)((x) & MASK32))
136
137	/* --- Safe shifting macros --- */
138
139	#define LSL8(v, s) U8(U8(v) << ((s) & 7u))
140	#define LSR8(v, s) U8(U8(v) >> ((s) & 7u))
141	#define LSL16(v, s) U16(U16(v) << ((s) & 15u))
142	#define LSR16(v, s) U16(U16(v) >> ((s) & 15u))
143	#define LSL24(v, s) U24(U24(v) << ((s) % 24u))
144	#define LSR24(v, s) U24(U24(v) >> ((s) % 24u))
145	#define LSL32(v, s) U32(U32(v) << ((s) & 31u))
146	#define LSR32(v, s) U32(U32(v) >> ((s) & 31u))
147
148	/* --- Rotation macros --- */
149
150	#define ROL8(v, s) (LSL8((v), (s)) \| (LSR8((v), 8u - (s))))
151	#define ROR8(v, s) (LSR8((v), (s)) \| (LSL8((v), 8u - (s))))
152	#define ROL16(v, s) (LSL16((v), (s)) \| (LSR16((v), 16u - (s))))
153	#define ROR16(v, s) (LSR16((v), (s)) \| (LSL16((v), 16u - (s))))
154	#define ROL24(v, s) (LSL24((v), (s)) \| (LSR24((v), 24u - (s))))
155	#define ROR24(v, s) (LSR24((v), (s)) \| (LSL24((v), 24u - (s))))
156	#define ROL32(v, s) (LSL32((v), (s)) \| (LSR32((v), 32u - (s))))
157	#define ROR32(v, s) (LSR32((v), (s)) \| (LSL32((v), 32u - (s))))
158
159	/* --- Storage and retrieval --- */
160
161	#define GETBYTE(p, o) (((octet *)(p))[o] & MASK8)
162	#define PUTBYTE(p, o, v) (((octet *)(p))[o] = U8((v)))
163
164	#define LOAD8(p) (GETBYTE((p), 0))
165	#define STORE8(p, v) (PUTBYTE((p), 0, (v)))
166
167	#define LOAD16_B(p) \
168	(((uint16)GETBYTE((p), 0) << 8) \| \
169	((uint16)GETBYTE((p), 1) << 0))
170	#define LOAD16_L(p) \
171	(((uint16)GETBYTE((p), 0) << 0) \| \
172	((uint16)GETBYTE((p), 1) << 8))
173	#define LOAD16(p) LOAD16_B((p))
174
175	#define STORE16_B(p, v) \
176	(PUTBYTE((p), 0, (uint16)(v) >> 8), \
177	PUTBYTE((p), 1, (uint16)(v) >> 0))
178	#define STORE16_L(p, v) \
179	(PUTBYTE((p), 0, (uint16)(v) >> 0), \
180	PUTBYTE((p), 1, (uint16)(v) >> 8))
181	#define STORE16(p, v) STORE16_B((p), (v))
182
183	#define LOAD24_B(p) \
184	(((uint24)GETBYTE((p), 0) << 16) \| \
185	((uint24)GETBYTE((p), 1) << 8) \| \
186	((uint24)GETBYTE((p), 2) << 0))
187	#define LOAD24_L(p) \
188	(((uint24)GETBYTE((p), 0) << 0) \| \
189	((uint24)GETBYTE((p), 1) << 8) \| \
190	((uint24)GETBYTE((p), 2) << 16))
191	#define LOAD24(p) LOAD24_B((p))
192
193	#define STORE24_B(p, v) \
194	(PUTBYTE((p), 0, (uint24)(v) >> 16), \
195	PUTBYTE((p), 1, (uint24)(v) >> 8), \
196	PUTBYTE((p), 2, (uint24)(v) >> 0))
197	#define STORE24_L(p, v) \
198	(PUTBYTE((p), 0, (uint24)(v) >> 0), \
199	PUTBYTE((p), 1, (uint24)(v) >> 8), \
200	PUTBYTE((p), 2, (uint24)(v) >> 16))
201	#define STORE24(p, v) STORE24_B((p), (v))
202
203	#define LOAD32_B(p) \
204	(((uint32)GETBYTE((p), 0) << 24) \| \
205	((uint32)GETBYTE((p), 1) << 16) \| \
206	((uint32)GETBYTE((p), 2) << 8) \| \
207	((uint32)GETBYTE((p), 3) << 0))
208	#define LOAD32_L(p) \
209	(((uint32)GETBYTE((p), 0) << 0) \| \
210	((uint32)GETBYTE((p), 1) << 8) \| \
211	((uint32)GETBYTE((p), 2) << 16) \| \
212	((uint32)GETBYTE((p), 3) << 24))
213	#define LOAD32(p) LOAD32_B((p))
214
215	#define STORE32_B(p, v) \
216	(PUTBYTE((p), 0, (uint32)(v) >> 24), \
217	PUTBYTE((p), 1, (uint32)(v) >> 16), \
218	PUTBYTE((p), 2, (uint32)(v) >> 8), \
219	PUTBYTE((p), 3, (uint32)(v) >> 0))
220	#define STORE32_L(p, v) \
221	(PUTBYTE((p), 0, (uint32)(v) >> 0), \
222	PUTBYTE((p), 1, (uint32)(v) >> 8), \
223	PUTBYTE((p), 2, (uint32)(v) >> 16), \
224	PUTBYTE((p), 3, (uint32)(v) >> 24))
225	#define STORE32(p, v) STORE32_B((p), (v))
226
227	/----- That's all, folks -------------------------------------------------/
228
229	#ifdef __cplusplus
230	}
231	#endif
232
233	#endif