[babeltrace.git] / include / babeltrace / bitfield.h

#ifndef _BABELTRACE_BITFIELD_H
#define _BABELTRACE_BITFIELD_H

/*
 * BabelTrace
 *
 * Bitfields read/write functions.
 *
 * Copyright 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 */

#include <stdint.h>	/* C99 5.2.4.2 Numerical limits */
#include <limits.h>	/* C99 5.2.4.2 Numerical limits */
#include <endian.h>	/* Non-standard BIG_ENDIAN, LITTLE_ENDIAN, BYTE_ORDER */
#include <assert.h>

/* We can't shift a int from 32 bit, >> 32 and << 32 on int is undefined */
#define _bt_piecewise_rshift(_v, _shift)				\
({									\
	typeof(_v) ___v = (_v);						\
	typeof(_shift) ___shift = (_shift);				\
	unsigned long sb = (___shift) / (sizeof(___v) * CHAR_BIT - 1);	\
	unsigned long final = (___shift) % (sizeof(___v) * CHAR_BIT - 1); \
									\
	for (; sb; sb--)						\
		___v >>= sizeof(___v) * CHAR_BIT - 1;			\
	___v >>= final;							\
})

#define _bt_piecewise_lshift(_v, _shift)				\
({									\
	typeof(_v) ___v = (_v);						\
	typeof(_shift) ___shift = (_shift);				\
	unsigned long sb = (___shift) / (sizeof(___v) * CHAR_BIT - 1);	\
	unsigned long final = (___shift) % (sizeof(___v) * CHAR_BIT - 1); \
									\
	for (; sb; sb--)						\
		___v <<= sizeof(___v) * CHAR_BIT - 1;			\
	___v <<= final;							\
})

#define _bt_is_signed_type(type)	(((type)(-1)) < 0)

#define _bt_unsigned_cast(type, v)					\
({									\
	(sizeof(v) < sizeof(type)) ?					\
		((type) (v)) & (~(~(type) 0 << (sizeof(v) * CHAR_BIT))) : \
		(type) (v);						\
})

/*
 * bt_bitfield_write - write integer to a bitfield in native endianness
 *
 * Save integer to the bitfield, which starts at the "start" bit, has "len"
 * bits.
 * The inside of a bitfield is from high bits to low bits.
 * Uses native endianness.
 * For unsigned "v", pad MSB with 0 if bitfield is larger than v.
 * For signed "v", sign-extend v if bitfield is larger than v.
 *
 * On little endian, bytes are placed from the less significant to the most
 * significant. Also, consecutive bitfields are placed from lower bits to higher
 * bits.
 *
 * On big endian, bytes are places from most significant to less significant.
 * Also, consecutive bitfields are placed from higher to lower bits.
 */

#define _bt_bitfield_write_le(_ptr, type, _start, _length, _v)		\
do {									\
	typeof(_v) __v = (_v);						\
	type *__ptr = (void *) (_ptr);					\
	unsigned long __start = (_start), __length = (_length);		\
	type mask, cmask;						\
	unsigned long ts = sizeof(type) * CHAR_BIT; /* type size */	\
	unsigned long start_unit, end_unit, this_unit;			\
	unsigned long end, cshift; /* cshift is "complement shift" */	\
									\
	if (!__length)							\
		break;							\
									\
	end = __start + __length;					\
	start_unit = __start / ts;					\
	end_unit = (end + (ts - 1)) / ts;				\
									\
	/* Trim v high bits */						\
	if (__length < sizeof(__v) * CHAR_BIT)				\
		__v &= ~((~(typeof(__v)) 0) << __length);		\
									\
	/* We can now append v with a simple "or", shift it piece-wise */ \
	this_unit = start_unit;						\
	if (start_unit == end_unit - 1) {				\
		mask = ~((~(type) 0) << (__start % ts));		\
		if (end % ts)						\
			mask |= (~(type) 0) << (end % ts);		\
		cmask = (type) __v << (__start % ts);			\
		cmask &= ~mask;						\
		__ptr[this_unit] &= mask;				\
		__ptr[this_unit] |= cmask;				\
		break;							\
	}								\
	if (__start % ts) {						\
		cshift = __start % ts;					\
		mask = ~((~(type) 0) << cshift);			\
		cmask = (type) __v << cshift;				\
		cmask &= ~mask;						\
		__ptr[this_unit] &= mask;				\
		__ptr[this_unit] |= cmask;				\
		__v = _bt_piecewise_rshift(__v, ts - cshift);		\
		__start += ts - cshift;					\
		this_unit++;						\
	}								\
	for (; this_unit < end_unit - 1; this_unit++) {			\
		__ptr[this_unit] = (type) __v;				\
		__v = _bt_piecewise_rshift(__v, ts);			\
		__start += ts;						\
	}								\
	if (end % ts) {							\
		mask = (~(type) 0) << (end % ts);			\
		cmask = (type) __v;					\
		cmask &= ~mask;						\
		__ptr[this_unit] &= mask;				\
		__ptr[this_unit] |= cmask;				\
	} else								\
		__ptr[this_unit] = (type) __v;				\
} while (0)

#define _bt_bitfield_write_be(_ptr, type, _start, _length, _v)		\
do {									\
	typeof(_v) __v = (_v);						\
	type *__ptr = (void *) (_ptr);					\
	unsigned long __start = (_start), __length = (_length);		\
	type mask, cmask;						\
	unsigned long ts = sizeof(type) * CHAR_BIT; /* type size */	\
	unsigned long start_unit, end_unit, this_unit;			\
	unsigned long end, cshift; /* cshift is "complement shift" */	\
									\
	if (!__length)							\
		break;							\
									\
	end = __start + __length;					\
	start_unit = __start / ts;					\
	end_unit = (end + (ts - 1)) / ts;				\
									\
	/* Trim v high bits */						\
	if (__length < sizeof(__v) * CHAR_BIT)				\
		__v &= ~((~(typeof(__v)) 0) << __length);		\
									\
	/* We can now append v with a simple "or", shift it piece-wise */ \
	this_unit = end_unit - 1;					\
	if (start_unit == end_unit - 1) {				\
		mask = ~((~(type) 0) << ((ts - (end % ts)) % ts));	\
		if (__start % ts)					\
			mask |= (~((type) 0)) << (ts - (__start % ts));	\
		cmask = (type) __v << ((ts - (end % ts)) % ts);		\
		cmask &= ~mask;						\
		__ptr[this_unit] &= mask;				\
		__ptr[this_unit] |= cmask;				\
		break;							\
	}								\
	if (end % ts) {							\
		cshift = end % ts;					\
		mask = ~((~(type) 0) << (ts - cshift));			\
		cmask = (type) __v << (ts - cshift);			\
		cmask &= ~mask;						\
		__ptr[this_unit] &= mask;				\
		__ptr[this_unit] |= cmask;				\
		__v = _bt_piecewise_rshift(__v, cshift);		\
		end -= cshift;						\
		this_unit--;						\
	}								\
	for (; (long) this_unit >= (long) start_unit + 1; this_unit--) { \
		__ptr[this_unit] = (type) __v;				\
		__v = _bt_piecewise_rshift(__v, ts);			\
		end -= ts;						\
	}								\
	if (__start % ts) {						\
		mask = (~(type) 0) << (ts - (__start % ts));		\
		cmask = (type) __v;					\
		cmask &= ~mask;						\
		__ptr[this_unit] &= mask;				\
		__ptr[this_unit] |= cmask;				\
	} else								\
		__ptr[this_unit] = (type) __v;				\
} while (0)

/*
 * bt_bitfield_write - write integer to a bitfield in native endianness
 * bt_bitfield_write_le - write integer to a bitfield in little endian
 * bt_bitfield_write_be - write integer to a bitfield in big endian
 */

#if (BYTE_ORDER == LITTLE_ENDIAN)

#define bt_bitfield_write(ptr, type, _start, _length, _v)		\
	_bt_bitfield_write_le(ptr, type, _start, _length, _v)

#define bt_bitfield_write_le(ptr, type, _start, _length, _v)		\
	_bt_bitfield_write_le(ptr, type, _start, _length, _v)
	
#define bt_bitfield_write_be(ptr, type, _start, _length, _v)		\
	_bt_bitfield_write_be(ptr, unsigned char, _start, _length, _v)

#elif (BYTE_ORDER == BIG_ENDIAN)

#define bt_bitfield_write(ptr, type, _start, _length, _v)		\
	_bt_bitfield_write_be(ptr, type, _start, _length, _v)

#define bt_bitfield_write_le(ptr, type, _start, _length, _v)		\
	_bt_bitfield_write_le(ptr, unsigned char, _start, _length, _v)
	
#define bt_bitfield_write_be(ptr, type, _start, _length, _v)		\
	_bt_bitfield_write_be(ptr, type, _start, _length, _v)

#else /* (BYTE_ORDER == PDP_ENDIAN) */

#error "Byte order not supported"

#endif

#define _bt_bitfield_read_le(_ptr, type, _start, _length, _vptr)	\
do {									\
	typeof(*(_vptr)) *__vptr = (_vptr);				\
	typeof(*__vptr) __v;						\
	type *__ptr = (void *) (_ptr);					\
	unsigned long __start = (_start), __length = (_length);		\
	type mask, cmask;						\
	unsigned long ts = sizeof(type) * CHAR_BIT; /* type size */	\
	unsigned long start_unit, end_unit, this_unit;			\
	unsigned long end, cshift; /* cshift is "complement shift" */	\
									\
	if (!__length) {						\
		*__vptr = 0;						\
		break;							\
	}								\
									\
	end = __start + __length;					\
	start_unit = __start / ts;					\
	end_unit = (end + (ts - 1)) / ts;				\
									\
	this_unit = end_unit - 1;					\
	if (_bt_is_signed_type(typeof(__v))				\
	    && (__ptr[this_unit] & ((type) 1 << ((end % ts ? : ts) - 1)))) \
		__v = ~(typeof(__v)) 0;					\
	else								\
		__v = 0;						\
	if (start_unit == end_unit - 1) {				\
		cmask = __ptr[this_unit];				\
		cmask >>= (__start % ts);				\
		if ((end - __start) % ts) {				\
			mask = ~((~(type) 0) << (end - __start));	\
			cmask &= mask;					\
		}							\
		__v = _bt_piecewise_lshift(__v, end - __start);		\
		__v |= _bt_unsigned_cast(typeof(__v), cmask);		\
		*__vptr = __v;						\
		break;							\
	}								\
	if (end % ts) {							\
		cshift = end % ts;					\
		mask = ~((~(type) 0) << cshift);			\
		cmask = __ptr[this_unit];				\
		cmask &= mask;						\
		__v = _bt_piecewise_lshift(__v, cshift);		\
		__v |= _bt_unsigned_cast(typeof(__v), cmask);		\
		end -= cshift;						\
		this_unit--;						\
	}								\
	for (; (long) this_unit >= (long) start_unit + 1; this_unit--) { \
		__v = _bt_piecewise_lshift(__v, ts);			\
		__v |= _bt_unsigned_cast(typeof(__v), __ptr[this_unit]);\
		end -= ts;						\
	}								\
	if (__start % ts) {						\
		mask = ~((~(type) 0) << (ts - (__start % ts)));		\
		cmask = __ptr[this_unit];				\
		cmask >>= (__start % ts);				\
		cmask &= mask;						\
		__v = _bt_piecewise_lshift(__v, ts - (__start % ts));	\
		__v |= _bt_unsigned_cast(typeof(__v), cmask);		\
	} else {							\
		__v = _bt_piecewise_lshift(__v, ts);			\
		__v |= _bt_unsigned_cast(typeof(__v), __ptr[this_unit]);\
	}								\
	*__vptr = __v;							\
} while (0)

#define _bt_bitfield_read_be(_ptr, type, _start, _length, _vptr)	\
do {									\
	typeof(*(_vptr)) *__vptr = (_vptr);				\
	typeof(*__vptr) __v;						\
	type *__ptr = (void *) (_ptr);					\
	unsigned long __start = (_start), __length = (_length);		\
	type mask, cmask;						\
	unsigned long ts = sizeof(type) * CHAR_BIT; /* type size */	\
	unsigned long start_unit, end_unit, this_unit;			\
	unsigned long end, cshift; /* cshift is "complement shift" */	\
									\
	if (!__length) {						\
		*__vptr = 0;						\
		break;							\
	}								\
									\
	end = __start + __length;					\
	start_unit = __start / ts;					\
	end_unit = (end + (ts - 1)) / ts;				\
									\
	this_unit = start_unit;						\
	if (_bt_is_signed_type(typeof(__v))				\
	    && (__ptr[this_unit] & ((type) 1 << (ts - (__start % ts) - 1)))) \
		__v = ~(typeof(__v)) 0;					\
	else								\
		__v = 0;						\
	if (start_unit == end_unit - 1) {				\
		cmask = __ptr[this_unit];				\
		cmask >>= (ts - (end % ts)) % ts;			\
		if ((end - __start) % ts) {				\
			mask = ~((~(type) 0) << (end - __start));	\
			cmask &= mask;					\
		}							\
		__v = _bt_piecewise_lshift(__v, end - __start);		\
		__v |= _bt_unsigned_cast(typeof(__v), cmask);		\
		*__vptr = __v;						\
		break;							\
	}								\
	if (__start % ts) {						\
		cshift = __start % ts;					\
		mask = ~((~(type) 0) << (ts - cshift));			\
		cmask = __ptr[this_unit];				\
		cmask &= mask;						\
		__v = _bt_piecewise_lshift(__v, ts - cshift);		\
		__v |= _bt_unsigned_cast(typeof(__v), cmask);		\
		__start += ts - cshift;					\
		this_unit++;						\
	}								\
	for (; this_unit < end_unit - 1; this_unit++) {			\
		__v = _bt_piecewise_lshift(__v, ts);			\
		__v |= _bt_unsigned_cast(typeof(__v), __ptr[this_unit]);\
		__start += ts;						\
	}								\
	if (end % ts) {							\
		mask = ~((~(type) 0) << (end % ts));			\
		cmask = __ptr[this_unit];				\
		cmask >>= ts - (end % ts);				\
		cmask &= mask;						\
		__v = _bt_piecewise_lshift(__v, end % ts);		\
		__v |= _bt_unsigned_cast(typeof(__v), cmask);		\
	} else {							\
		__v = _bt_piecewise_lshift(__v, ts);			\
		__v |= _bt_unsigned_cast(typeof(__v), __ptr[this_unit]);\
	}								\
	*__vptr = __v;							\
} while (0)

/*
 * bt_bitfield_read - read integer from a bitfield in native endianness
 * bt_bitfield_read_le - read integer from a bitfield in little endian
 * bt_bitfield_read_be - read integer from a bitfield in big endian
 */

#if (BYTE_ORDER == LITTLE_ENDIAN)

#define bt_bitfield_read(_ptr, type, _start, _length, _vptr)		\
	_bt_bitfield_read_le(_ptr, type, _start, _length, _vptr)

#define bt_bitfield_read_le(_ptr, type, _start, _length, _vptr)		\
	_bt_bitfield_read_le(_ptr, type, _start, _length, _vptr)
	
#define bt_bitfield_read_be(_ptr, type, _start, _length, _vptr)		\
	_bt_bitfield_read_be(_ptr, unsigned char, _start, _length, _vptr)

#elif (BYTE_ORDER == BIG_ENDIAN)

#define bt_bitfield_read(_ptr, type, _start, _length, _vptr)		\
	_bt_bitfield_read_be(_ptr, type, _start, _length, _vptr)

#define bt_bitfield_read_le(_ptr, type, _start, _length, _vptr)		\
	_bt_bitfield_read_le(_ptr, unsigned char, _start, _length, _vptr)
	
#define bt_bitfield_read_be(_ptr, type, _start, _length, _vptr)		\
	_bt_bitfield_read_be(_ptr, type, _start, _length, _vptr)

#else /* (BYTE_ORDER == PDP_ENDIAN) */

#error "Byte order not supported"

#endif

#endif /* _BABELTRACE_BITFIELD_H */
Commit	Line	Data
d79865b9 MD	1	#ifndef _BABELTRACE_BITFIELD_H
d79865b9 MD	2	#define _BABELTRACE_BITFIELD_H
6dc2ca62 MD	3
6dc2ca62 MD	4	/*
d79865b9	5	* BabelTrace
6dc2ca62 MD	6	*
	7	* Bitfields read/write functions.
	8	*
	9	* Copyright 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	10	*
	11	* Permission is hereby granted, free of charge, to any person obtaining a copy
	12	* of this software and associated documentation files (the "Software"), to deal
	13	* in the Software without restriction, including without limitation the rights
	14	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	15	* copies of the Software, and to permit persons to whom the Software is
	16	* furnished to do so, subject to the following conditions:
	17	*
	18	* The above copyright notice and this permission notice shall be included in
	19	* all copies or substantial portions of the Software.
	20	*/
	21
	22	#include <stdint.h> /* C99 5.2.4.2 Numerical limits */
	23	#include <limits.h> /* C99 5.2.4.2 Numerical limits */
	24	#include <endian.h> /* Non-standard BIG_ENDIAN, LITTLE_ENDIAN, BYTE_ORDER */
	25	#include <assert.h>
	26
08228826	27	/* We can't shift a int from 32 bit, >> 32 and << 32 on int is undefined */
5f61bf21	28	#define _bt_piecewise_rshift(_v, _shift) \
6dc2ca62	29	({ \
5f61bf21 MD	30	typeof(_v) ___v = (_v); \
	31	typeof(_shift) ___shift = (_shift); \
	32	unsigned long sb = (___shift) / (sizeof(___v) * CHAR_BIT - 1); \
	33	unsigned long final = (___shift) % (sizeof(___v) * CHAR_BIT - 1); \
6dc2ca62 MD	34	\
6dc2ca62 MD	35	for (; sb; sb--) \
5f61bf21 MD	36	___v >>= sizeof(___v) * CHAR_BIT - 1; \
5f61bf21 MD	37	___v >>= final; \
6dc2ca62 MD	38	})
6dc2ca62 MD	39
5f61bf21	40	#define _bt_piecewise_lshift(_v, _shift) \
08228826	41	({ \
5f61bf21 MD	42	typeof(_v) ___v = (_v); \
	43	typeof(_shift) ___shift = (_shift); \
	44	unsigned long sb = (___shift) / (sizeof(___v) * CHAR_BIT - 1); \
	45	unsigned long final = (___shift) % (sizeof(___v) * CHAR_BIT - 1); \
08228826 MD	46	\
08228826 MD	47	for (; sb; sb--) \
5f61bf21 MD	48	___v <<= sizeof(___v) * CHAR_BIT - 1; \
5f61bf21 MD	49	___v <<= final; \
08228826 MD	50	})
08228826 MD	51
d79865b9	52	#define _bt_is_signed_type(type) (((type)(-1)) < 0)
08228826	53
d79865b9	54	#define _bt_unsigned_cast(type, v) \
08228826 MD	55	({ \
	56	(sizeof(v) < sizeof(type)) ? \
	57	((type) (v)) & (~(~(type) 0 << (sizeof(v) * CHAR_BIT))) : \
	58	(type) (v); \
	59	})
	60
6dc2ca62	61	/*
d79865b9	62	* bt_bitfield_write - write integer to a bitfield in native endianness
6dc2ca62 MD	63	*
	64	* Save integer to the bitfield, which starts at the "start" bit, has "len"
	65	* bits.
	66	* The inside of a bitfield is from high bits to low bits.
	67	* Uses native endianness.
	68	* For unsigned "v", pad MSB with 0 if bitfield is larger than v.
	69	* For signed "v", sign-extend v if bitfield is larger than v.
	70	*
	71	* On little endian, bytes are placed from the less significant to the most
	72	* significant. Also, consecutive bitfields are placed from lower bits to higher
	73	* bits.
	74	*
	75	* On big endian, bytes are places from most significant to less significant.
	76	* Also, consecutive bitfields are placed from higher to lower bits.
	77	*/
	78
5f61bf21	79	#define _bt_bitfield_write_le(_ptr, type, _start, _length, _v) \
6dc2ca62	80	do { \
5f61bf21	81	typeof(_v) __v = (_v); \
9128428b	82	type __ptr = (void ) (_ptr); \
5f61bf21	83	unsigned long __start = (_start), __length = (_length); \
47e0f2e2 MD	84	type mask, cmask; \
47e0f2e2 MD	85	unsigned long ts = sizeof(type) * CHAR_BIT; /* type size */ \
6dc2ca62 MD	86	unsigned long start_unit, end_unit, this_unit; \
6dc2ca62 MD	87	unsigned long end, cshift; /* cshift is "complement shift" */ \
6dc2ca62	88	\
5f61bf21	89	if (!__length) \
6dc2ca62 MD	90	break; \
6dc2ca62 MD	91	\
5f61bf21 MD	92	end = __start + __length; \
5f61bf21 MD	93	start_unit = __start / ts; \
6dc2ca62 MD	94	end_unit = (end + (ts - 1)) / ts; \
	95	\
	96	/* Trim v high bits */ \
5f61bf21 MD	97	if (__length < sizeof(__v) * CHAR_BIT) \
5f61bf21 MD	98	__v &= ~((~(typeof(__v)) 0) << __length); \
6dc2ca62 MD	99	\
	100	/* We can now append v with a simple "or", shift it piece-wise */ \
	101	this_unit = start_unit; \
	102	if (start_unit == end_unit - 1) { \
5f61bf21	103	mask = ~((~(type) 0) << (__start % ts)); \
6dc2ca62	104	if (end % ts) \
47e0f2e2	105	mask \|= (~(type) 0) << (end % ts); \
5f61bf21	106	cmask = (type) __v << (__start % ts); \
08228826	107	cmask &= ~mask; \
5f61bf21 MD	108	__ptr[this_unit] &= mask; \
5f61bf21 MD	109	__ptr[this_unit] \|= cmask; \
6dc2ca62 MD	110	break; \
6dc2ca62 MD	111	} \
5f61bf21 MD	112	if (__start % ts) { \
5f61bf21 MD	113	cshift = __start % ts; \
47e0f2e2	114	mask = ~((~(type) 0) << cshift); \
5f61bf21	115	cmask = (type) __v << cshift; \
08228826	116	cmask &= ~mask; \
5f61bf21 MD	117	__ptr[this_unit] &= mask; \
	118	__ptr[this_unit] \|= cmask; \
	119	__v = _bt_piecewise_rshift(__v, ts - cshift); \
	120	__start += ts - cshift; \
6dc2ca62 MD	121	this_unit++; \
	122	} \
	123	for (; this_unit < end_unit - 1; this_unit++) { \
5f61bf21 MD	124	__ptr[this_unit] = (type) __v; \
	125	__v = _bt_piecewise_rshift(__v, ts); \
	126	__start += ts; \
6dc2ca62 MD	127	} \
6dc2ca62 MD	128	if (end % ts) { \
47e0f2e2	129	mask = (~(type) 0) << (end % ts); \
5f61bf21	130	cmask = (type) __v; \
08228826	131	cmask &= ~mask; \
5f61bf21 MD	132	__ptr[this_unit] &= mask; \
5f61bf21 MD	133	__ptr[this_unit] \|= cmask; \
6dc2ca62	134	} else \
5f61bf21	135	__ptr[this_unit] = (type) __v; \
6dc2ca62 MD	136	} while (0)
6dc2ca62 MD	137
5f61bf21	138	#define _bt_bitfield_write_be(_ptr, type, _start, _length, _v) \
6dc2ca62	139	do { \
5f61bf21	140	typeof(_v) __v = (_v); \
9128428b	141	type __ptr = (void ) (_ptr); \
5f61bf21	142	unsigned long __start = (_start), __length = (_length); \
47e0f2e2 MD	143	type mask, cmask; \
47e0f2e2 MD	144	unsigned long ts = sizeof(type) * CHAR_BIT; /* type size */ \
6dc2ca62 MD	145	unsigned long start_unit, end_unit, this_unit; \
6dc2ca62 MD	146	unsigned long end, cshift; /* cshift is "complement shift" */ \
6dc2ca62	147	\
5f61bf21	148	if (!__length) \
6dc2ca62 MD	149	break; \
6dc2ca62 MD	150	\
5f61bf21 MD	151	end = __start + __length; \
5f61bf21 MD	152	start_unit = __start / ts; \
6dc2ca62 MD	153	end_unit = (end + (ts - 1)) / ts; \
	154	\
	155	/* Trim v high bits */ \
5f61bf21 MD	156	if (__length < sizeof(__v) * CHAR_BIT) \
5f61bf21 MD	157	__v &= ~((~(typeof(__v)) 0) << __length); \
6dc2ca62 MD	158	\
	159	/* We can now append v with a simple "or", shift it piece-wise */ \
	160	this_unit = end_unit - 1; \
	161	if (start_unit == end_unit - 1) { \
47e0f2e2	162	mask = ~((~(type) 0) << ((ts - (end % ts)) % ts)); \
5f61bf21 MD	163	if (__start % ts) \
	164	mask \|= (~((type) 0)) << (ts - (__start % ts)); \
	165	cmask = (type) __v << ((ts - (end % ts)) % ts); \
08228826	166	cmask &= ~mask; \
5f61bf21 MD	167	__ptr[this_unit] &= mask; \
5f61bf21 MD	168	__ptr[this_unit] \|= cmask; \
6dc2ca62 MD	169	break; \
	170	} \
	171	if (end % ts) { \
	172	cshift = end % ts; \
47e0f2e2	173	mask = ~((~(type) 0) << (ts - cshift)); \
5f61bf21	174	cmask = (type) __v << (ts - cshift); \
08228826	175	cmask &= ~mask; \
5f61bf21 MD	176	__ptr[this_unit] &= mask; \
	177	__ptr[this_unit] \|= cmask; \
	178	__v = _bt_piecewise_rshift(__v, cshift); \
6dc2ca62 MD	179	end -= cshift; \
	180	this_unit--; \
	181	} \
08228826	182	for (; (long) this_unit >= (long) start_unit + 1; this_unit--) { \
5f61bf21 MD	183	__ptr[this_unit] = (type) __v; \
5f61bf21 MD	184	__v = _bt_piecewise_rshift(__v, ts); \
6dc2ca62 MD	185	end -= ts; \
6dc2ca62 MD	186	} \
5f61bf21 MD	187	if (__start % ts) { \
	188	mask = (~(type) 0) << (ts - (__start % ts)); \
	189	cmask = (type) __v; \
08228826	190	cmask &= ~mask; \
5f61bf21 MD	191	__ptr[this_unit] &= mask; \
5f61bf21 MD	192	__ptr[this_unit] \|= cmask; \
6dc2ca62	193	} else \
5f61bf21	194	__ptr[this_unit] = (type) __v; \
6dc2ca62 MD	195	} while (0)
	196
	197	/*
d79865b9 MD	198	* bt_bitfield_write - write integer to a bitfield in native endianness
	199	* bt_bitfield_write_le - write integer to a bitfield in little endian
	200	* bt_bitfield_write_be - write integer to a bitfield in big endian
6dc2ca62 MD	201	*/
	202
	203	#if (BYTE_ORDER == LITTLE_ENDIAN)
	204
47e0f2e2 MD	205	#define bt_bitfield_write(ptr, type, _start, _length, _v) \
47e0f2e2 MD	206	_bt_bitfield_write_le(ptr, type, _start, _length, _v)
6dc2ca62	207
47e0f2e2 MD	208	#define bt_bitfield_write_le(ptr, type, _start, _length, _v) \
47e0f2e2 MD	209	_bt_bitfield_write_le(ptr, type, _start, _length, _v)
6dc2ca62	210
47e0f2e2 MD	211	#define bt_bitfield_write_be(ptr, type, _start, _length, _v) \
47e0f2e2 MD	212	_bt_bitfield_write_be(ptr, unsigned char, _start, _length, _v)
6dc2ca62 MD	213
	214	#elif (BYTE_ORDER == BIG_ENDIAN)
	215
47e0f2e2 MD	216	#define bt_bitfield_write(ptr, type, _start, _length, _v) \
47e0f2e2 MD	217	_bt_bitfield_write_be(ptr, type, _start, _length, _v)
6dc2ca62	218
47e0f2e2 MD	219	#define bt_bitfield_write_le(ptr, type, _start, _length, _v) \
47e0f2e2 MD	220	_bt_bitfield_write_le(ptr, unsigned char, _start, _length, _v)
6dc2ca62	221
47e0f2e2 MD	222	#define bt_bitfield_write_be(ptr, type, _start, _length, _v) \
47e0f2e2 MD	223	_bt_bitfield_write_be(ptr, type, _start, _length, _v)
6dc2ca62 MD	224
	225	#else /* (BYTE_ORDER == PDP_ENDIAN) */
	226
	227	#error "Byte order not supported"
	228
	229	#endif
	230
5f61bf21	231	#define _bt_bitfield_read_le(_ptr, type, _start, _length, _vptr) \
6dc2ca62	232	do { \
5f61bf21	233	typeof((_vptr)) __vptr = (_vptr); \
5f61bf21	234	typeof(*__vptr) __v; \
9128428b	235	type __ptr = (void ) (_ptr); \
5f61bf21	236	unsigned long __start = (_start), __length = (_length); \
47e0f2e2 MD	237	type mask, cmask; \
47e0f2e2 MD	238	unsigned long ts = sizeof(type) * CHAR_BIT; /* type size */ \
6dc2ca62 MD	239	unsigned long start_unit, end_unit, this_unit; \
6dc2ca62 MD	240	unsigned long end, cshift; /* cshift is "complement shift" */ \
08228826	241	\
5f61bf21 MD	242	if (!__length) { \
5f61bf21 MD	243	*__vptr = 0; \
08228826 MD	244	break; \
	245	} \
	246	\
5f61bf21 MD	247	end = __start + __length; \
5f61bf21 MD	248	start_unit = __start / ts; \
08228826	249	end_unit = (end + (ts - 1)) / ts; \
6a7b3345 MD	250	\
6a7b3345 MD	251	this_unit = end_unit - 1; \
5f61bf21 MD	252	if (_bt_is_signed_type(typeof(__v)) \
	253	&& (__ptr[this_unit] & ((type) 1 << ((end % ts ? : ts) - 1)))) \
	254	__v = ~(typeof(__v)) 0; \
6a7b3345	255	else \
5f61bf21	256	__v = 0; \
6a7b3345	257	if (start_unit == end_unit - 1) { \
5f61bf21 MD	258	cmask = __ptr[this_unit]; \
	259	cmask >>= (__start % ts); \
	260	if ((end - __start) % ts) { \
	261	mask = ~((~(type) 0) << (end - __start)); \
6a7b3345 MD	262	cmask &= mask; \
6a7b3345 MD	263	} \
5f61bf21 MD	264	__v = _bt_piecewise_lshift(__v, end - __start); \
	265	__v \|= _bt_unsigned_cast(typeof(__v), cmask); \
	266	*__vptr = __v; \
6a7b3345 MD	267	break; \
	268	} \
	269	if (end % ts) { \
	270	cshift = end % ts; \
47e0f2e2	271	mask = ~((~(type) 0) << cshift); \
5f61bf21	272	cmask = __ptr[this_unit]; \
6a7b3345	273	cmask &= mask; \
5f61bf21 MD	274	__v = _bt_piecewise_lshift(__v, cshift); \
5f61bf21 MD	275	__v \|= _bt_unsigned_cast(typeof(__v), cmask); \
6a7b3345 MD	276	end -= cshift; \
	277	this_unit--; \
	278	} \
08228826	279	for (; (long) this_unit >= (long) start_unit + 1; this_unit--) { \
5f61bf21 MD	280	__v = _bt_piecewise_lshift(__v, ts); \
5f61bf21 MD	281	__v \|= _bt_unsigned_cast(typeof(__v), __ptr[this_unit]);\
6a7b3345 MD	282	end -= ts; \
6a7b3345 MD	283	} \
5f61bf21 MD	284	if (__start % ts) { \
	285	mask = ~((~(type) 0) << (ts - (__start % ts))); \
	286	cmask = __ptr[this_unit]; \
	287	cmask >>= (__start % ts); \
6a7b3345	288	cmask &= mask; \
5f61bf21 MD	289	__v = _bt_piecewise_lshift(__v, ts - (__start % ts)); \
5f61bf21 MD	290	__v \|= _bt_unsigned_cast(typeof(__v), cmask); \
6a7b3345	291	} else { \
5f61bf21 MD	292	__v = _bt_piecewise_lshift(__v, ts); \
5f61bf21 MD	293	__v \|= _bt_unsigned_cast(typeof(__v), __ptr[this_unit]);\
6a7b3345	294	} \
5f61bf21	295	*__vptr = __v; \
08228826 MD	296	} while (0)
08228826 MD	297
5f61bf21	298	#define _bt_bitfield_read_be(_ptr, type, _start, _length, _vptr) \
08228826	299	do { \
5f61bf21	300	typeof((_vptr)) __vptr = (_vptr); \
5f61bf21	301	typeof(*__vptr) __v; \
9128428b	302	type __ptr = (void ) (_ptr); \
5f61bf21	303	unsigned long __start = (_start), __length = (_length); \
47e0f2e2 MD	304	type mask, cmask; \
47e0f2e2 MD	305	unsigned long ts = sizeof(type) * CHAR_BIT; /* type size */ \
08228826 MD	306	unsigned long start_unit, end_unit, this_unit; \
08228826 MD	307	unsigned long end, cshift; /* cshift is "complement shift" */ \
6dc2ca62	308	\
5f61bf21 MD	309	if (!__length) { \
5f61bf21 MD	310	*__vptr = 0; \
6dc2ca62	311	break; \
08228826	312	} \
6dc2ca62	313	\
5f61bf21 MD	314	end = __start + __length; \
5f61bf21 MD	315	start_unit = __start / ts; \
6dc2ca62	316	end_unit = (end + (ts - 1)) / ts; \
6a7b3345	317	\
08228826	318	this_unit = start_unit; \
5f61bf21 MD	319	if (_bt_is_signed_type(typeof(__v)) \
	320	&& (__ptr[this_unit] & ((type) 1 << (ts - (__start % ts) - 1)))) \
	321	__v = ~(typeof(__v)) 0; \
6a7b3345	322	else \
5f61bf21	323	__v = 0; \
6a7b3345	324	if (start_unit == end_unit - 1) { \
5f61bf21	325	cmask = __ptr[this_unit]; \
6a7b3345	326	cmask >>= (ts - (end % ts)) % ts; \
5f61bf21 MD	327	if ((end - __start) % ts) { \
5f61bf21 MD	328	mask = ~((~(type) 0) << (end - __start)); \
6a7b3345 MD	329	cmask &= mask; \
6a7b3345 MD	330	} \
5f61bf21 MD	331	__v = _bt_piecewise_lshift(__v, end - __start); \
	332	__v \|= _bt_unsigned_cast(typeof(__v), cmask); \
	333	*__vptr = __v; \
6a7b3345 MD	334	break; \
6a7b3345 MD	335	} \
5f61bf21 MD	336	if (__start % ts) { \
5f61bf21 MD	337	cshift = __start % ts; \
47e0f2e2	338	mask = ~((~(type) 0) << (ts - cshift)); \
5f61bf21	339	cmask = __ptr[this_unit]; \
6a7b3345	340	cmask &= mask; \
5f61bf21 MD	341	__v = _bt_piecewise_lshift(__v, ts - cshift); \
	342	__v \|= _bt_unsigned_cast(typeof(__v), cmask); \
	343	__start += ts - cshift; \
6a7b3345 MD	344	this_unit++; \
	345	} \
	346	for (; this_unit < end_unit - 1; this_unit++) { \
5f61bf21 MD	347	__v = _bt_piecewise_lshift(__v, ts); \
	348	__v \|= _bt_unsigned_cast(typeof(__v), __ptr[this_unit]);\
	349	__start += ts; \
6a7b3345 MD	350	} \
6a7b3345 MD	351	if (end % ts) { \
47e0f2e2	352	mask = ~((~(type) 0) << (end % ts)); \
5f61bf21	353	cmask = __ptr[this_unit]; \
6a7b3345 MD	354	cmask >>= ts - (end % ts); \
6a7b3345 MD	355	cmask &= mask; \
5f61bf21 MD	356	__v = _bt_piecewise_lshift(__v, end % ts); \
5f61bf21 MD	357	__v \|= _bt_unsigned_cast(typeof(__v), cmask); \
6a7b3345	358	} else { \
5f61bf21 MD	359	__v = _bt_piecewise_lshift(__v, ts); \
5f61bf21 MD	360	__v \|= _bt_unsigned_cast(typeof(__v), __ptr[this_unit]);\
6a7b3345	361	} \
5f61bf21	362	*__vptr = __v; \
6dc2ca62 MD	363	} while (0)
6dc2ca62 MD	364
6dc2ca62	365	/*
d79865b9 MD	366	* bt_bitfield_read - read integer from a bitfield in native endianness
	367	* bt_bitfield_read_le - read integer from a bitfield in little endian
	368	* bt_bitfield_read_be - read integer from a bitfield in big endian
6dc2ca62 MD	369	*/
6dc2ca62 MD	370
08228826 MD	371	#if (BYTE_ORDER == LITTLE_ENDIAN)
08228826 MD	372
5f61bf21 MD	373	#define bt_bitfield_read(_ptr, type, _start, _length, _vptr) \
5f61bf21 MD	374	_bt_bitfield_read_le(_ptr, type, _start, _length, _vptr)
08228826	375
5f61bf21 MD	376	#define bt_bitfield_read_le(_ptr, type, _start, _length, _vptr) \
5f61bf21 MD	377	_bt_bitfield_read_le(_ptr, type, _start, _length, _vptr)
08228826	378
5f61bf21 MD	379	#define bt_bitfield_read_be(_ptr, type, _start, _length, _vptr) \
5f61bf21 MD	380	_bt_bitfield_read_be(_ptr, unsigned char, _start, _length, _vptr)
08228826 MD	381
	382	#elif (BYTE_ORDER == BIG_ENDIAN)
	383
5f61bf21 MD	384	#define bt_bitfield_read(_ptr, type, _start, _length, _vptr) \
5f61bf21 MD	385	_bt_bitfield_read_be(_ptr, type, _start, _length, _vptr)
08228826	386
5f61bf21 MD	387	#define bt_bitfield_read_le(_ptr, type, _start, _length, _vptr) \
5f61bf21 MD	388	_bt_bitfield_read_le(_ptr, unsigned char, _start, _length, _vptr)
08228826	389
5f61bf21 MD	390	#define bt_bitfield_read_be(_ptr, type, _start, _length, _vptr) \
5f61bf21 MD	391	_bt_bitfield_read_be(_ptr, type, _start, _length, _vptr)
08228826 MD	392
	393	#else /* (BYTE_ORDER == PDP_ENDIAN) */
	394
	395	#error "Byte order not supported"
	396
	397	#endif
6dc2ca62	398
d79865b9	399	#endif /* _BABELTRACE_BITFIELD_H */