[storin] / bits.h

/* -*-c-*-
 *
 * $Id$
 *
 * 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 AUTHORS 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 1.2  2000/07/02 15:21:20  mdw
 * Fix licence text.
 *
 * 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--
e6e0e332 MW	2	*
05dfc037	3	* $Id$
e6e0e332 MW	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
6b2d9d76	34	* NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
e6e0e332 MW	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 $
6b2d9d76 MW	53	* Revision 1.2 2000/07/02 15:21:20 mdw
	54	* Fix licence text.
	55	*
e6e0e332 MW	56	* Revision 1.1 2000/05/21 11:28:30 mdw
	57	* Initial check-in.
	58	*
	59	* --- Past lives (mLib) --- *
	60	*
	61	* Revision 1.4 1999/12/10 23:42:04 mdw
	62	* Change header file guard names.
	63	*
	64	* Revision 1.3 1999/06/20 23:31:52 mdw
	65	* More portability enhancements.
	66	*
	67	* Revision 1.2 1999/06/17 00:12:46 mdw
	68	* Improve portability for shift and rotate macros.
	69	*
	70	* Revision 1.1 1999/06/01 09:46:19 mdw
	71	* New addition: bit manipulation macros.
	72	*/
	73
	74	#ifndef BITS_H
	75	#define BITS_H
	76
	77	#ifdef __cplusplus
	78	extern "C" {
	79	#endif
	80
	81	/----- Header files ------------------------------------------------------/
	82
	83	#include <limits.h>
	84	#include <stddef.h>
	85
	86	/----- Decide on some types ----------------------------------------------/
	87
	88	/* --- Decide on a 32-bit type --- *
	89	*
	90	* I want a type which is capable of expressing 32-bit numbers. Because some
	91	* implementations have 64-bit @long@s (infinitely preferable to the abortion
	92	* that is @long long@), using @unsigned long@ regardless is wasteful. So,
	93	* if @int@ appears to be good enough, then I'll go with that.
	94	*/
	95
	96	#if UINT_MAX >= 0xffffffffu
	97	typedef unsigned int uint32;
	98	#else
	99	typedef unsigned long uint32;
	100	#endif
	101
	102	/* --- Decide on a 24-bit type --- */
	103
	104	#if UINT_MAX >= 0x00ffffffu
	105	typedef unsigned int uint24;
	106	#else
	107	typedef unsigned long uint24;
	108	#endif
	109
	110	/* --- Decide on 16-bit and 8-bit types --- *
	111	*
	112	* This is more for brevity than anything else.
	113	*/
	114
	115	typedef unsigned short uint16;
	116	typedef unsigned char octet;
	117
	118	/* --- WARNING! --- *
	119	*
120	* Never lose sight of the fact that the above types may be wider than the
121	* names suggest. Some architectures have 32-bit @short@s for example.
122	*/
123
124	/----- Macros ------------------------------------------------------------/
125
126	/* --- Useful masks --- */
127
128	#define MASK8 0xffu
129	#define MASK16 0xffffu
130	#define MASK24 0xffffffu
131	#define MASK32 0xffffffffu
132
133	/* --- Type coercions --- */
134
135	#define U8(x) ((octet)((x) & MASK8))
136	#define U16(x) ((uint16)((x) & MASK16))
137	#define U24(x) ((uint24)((x) & MASK24))
138	#define U32(x) ((uint32)((x) & MASK32))
139
140	/* --- Safe shifting macros --- */
141
142	#define LSL8(v, s) U8(U8(v) << ((s) & 7u))
143	#define LSR8(v, s) U8(U8(v) >> ((s) & 7u))
144	#define LSL16(v, s) U16(U16(v) << ((s) & 15u))
145	#define LSR16(v, s) U16(U16(v) >> ((s) & 15u))
146	#define LSL24(v, s) U24(U24(v) << ((s) % 24u))
147	#define LSR24(v, s) U24(U24(v) >> ((s) % 24u))
148	#define LSL32(v, s) U32(U32(v) << ((s) & 31u))
149	#define LSR32(v, s) U32(U32(v) >> ((s) & 31u))
150
151	/* --- Rotation macros --- */
152
153	#define ROL8(v, s) (LSL8((v), (s)) \| (LSR8((v), 8u - (s))))
154	#define ROR8(v, s) (LSR8((v), (s)) \| (LSL8((v), 8u - (s))))
155	#define ROL16(v, s) (LSL16((v), (s)) \| (LSR16((v), 16u - (s))))
156	#define ROR16(v, s) (LSR16((v), (s)) \| (LSL16((v), 16u - (s))))
157	#define ROL24(v, s) (LSL24((v), (s)) \| (LSR24((v), 24u - (s))))
158	#define ROR24(v, s) (LSR24((v), (s)) \| (LSL24((v), 24u - (s))))
159	#define ROL32(v, s) (LSL32((v), (s)) \| (LSR32((v), 32u - (s))))
160	#define ROR32(v, s) (LSR32((v), (s)) \| (LSL32((v), 32u - (s))))
161
162	/* --- Storage and retrieval --- */
163
164	#define GETBYTE(p, o) (((octet *)(p))[o] & MASK8)
165	#define PUTBYTE(p, o, v) (((octet *)(p))[o] = U8((v)))
166
167	#define LOAD8(p) (GETBYTE((p), 0))
168	#define STORE8(p, v) (PUTBYTE((p), 0, (v)))
169
170	#define LOAD16_B(p) \
171	(((uint16)GETBYTE((p), 0) << 8) \| \
172	((uint16)GETBYTE((p), 1) << 0))
173	#define LOAD16_L(p) \
174	(((uint16)GETBYTE((p), 0) << 0) \| \
175	((uint16)GETBYTE((p), 1) << 8))
176	#define LOAD16(p) LOAD16_B((p))
177
178	#define STORE16_B(p, v) \
179	(PUTBYTE((p), 0, (uint16)(v) >> 8), \
180	PUTBYTE((p), 1, (uint16)(v) >> 0))
181	#define STORE16_L(p, v) \
182	(PUTBYTE((p), 0, (uint16)(v) >> 0), \
183	PUTBYTE((p), 1, (uint16)(v) >> 8))
184	#define STORE16(p, v) STORE16_B((p), (v))
185
186	#define LOAD24_B(p) \
187	(((uint24)GETBYTE((p), 0) << 16) \| \
188	((uint24)GETBYTE((p), 1) << 8) \| \
189	((uint24)GETBYTE((p), 2) << 0))
190	#define LOAD24_L(p) \
191	(((uint24)GETBYTE((p), 0) << 0) \| \
192	((uint24)GETBYTE((p), 1) << 8) \| \
193	((uint24)GETBYTE((p), 2) << 16))
194	#define LOAD24(p) LOAD24_B((p))
195
196	#define STORE24_B(p, v) \
197	(PUTBYTE((p), 0, (uint24)(v) >> 16), \
198	PUTBYTE((p), 1, (uint24)(v) >> 8), \
199	PUTBYTE((p), 2, (uint24)(v) >> 0))
200	#define STORE24_L(p, v) \
201	(PUTBYTE((p), 0, (uint24)(v) >> 0), \
202	PUTBYTE((p), 1, (uint24)(v) >> 8), \
203	PUTBYTE((p), 2, (uint24)(v) >> 16))
204	#define STORE24(p, v) STORE24_B((p), (v))
205
206	#define LOAD32_B(p) \
207	(((uint32)GETBYTE((p), 0) << 24) \| \
208	((uint32)GETBYTE((p), 1) << 16) \| \
209	((uint32)GETBYTE((p), 2) << 8) \| \
210	((uint32)GETBYTE((p), 3) << 0))
211	#define LOAD32_L(p) \
212	(((uint32)GETBYTE((p), 0) << 0) \| \
213	((uint32)GETBYTE((p), 1) << 8) \| \
214	((uint32)GETBYTE((p), 2) << 16) \| \
215	((uint32)GETBYTE((p), 3) << 24))
216	#define LOAD32(p) LOAD32_B((p))
217
218	#define STORE32_B(p, v) \
219	(PUTBYTE((p), 0, (uint32)(v) >> 24), \
220	PUTBYTE((p), 1, (uint32)(v) >> 16), \
221	PUTBYTE((p), 2, (uint32)(v) >> 8), \
222	PUTBYTE((p), 3, (uint32)(v) >> 0))
223	#define STORE32_L(p, v) \
224	(PUTBYTE((p), 0, (uint32)(v) >> 0), \
225	PUTBYTE((p), 1, (uint32)(v) >> 8), \
226	PUTBYTE((p), 2, (uint32)(v) >> 16), \
227	PUTBYTE((p), 3, (uint32)(v) >> 24))
228	#define STORE32(p, v) STORE32_B((p), (v))
229
230	/----- That's all, folks -------------------------------------------------/
231
232	#ifdef __cplusplus
233	}
234	#endif
235
236	#endif