4 * Copyright 2003, 2004 Develer S.r.l. (http://www.develer.com/)
5 * This file is part of DevLib - See devlib/README for information.
8 * \brief Common and handy function macros
11 * \author Bernardo Innocenti <bernie@develer.com>
12 * \author Giovanni Bajo <rasky@develer.com>
17 *#* Revision 1.7 2004/09/20 03:30:45 bernie
18 *#* C++ also has variadic macros.
20 *#* Revision 1.6 2004/09/14 21:02:04 bernie
21 *#* SWAP(), MINMAX(): New macros.
23 *#* Revision 1.5 2004/08/29 21:57:58 bernie
24 *#* Move back STATIC_ASSERT() to compiler.h as it's needed in cpu.h;
25 *#* iptr_t, const_iptr_t: Replace IPTR macro with a real typedef.
27 *#* Revision 1.3 2004/08/24 14:13:48 bernie
28 *#* Restore a few macros that were lost in the way.
30 *#* Revision 1.2 2004/08/24 13:32:14 bernie
31 *#* PP_CAT(), PP_STRINGIZE(): Move back to compiler.h to break circular dependency between cpu.h/compiler.h/macros.h;
32 *#* offsetof(), countof(): Move back to compiler.h to avoid including macros.h almost everywhere;
34 *#* Rename header guards;
35 *#* Don't include arch_config.h in compiler.h as it's not needed there.
37 *#* Revision 1.1 2004/08/14 19:37:57 rasky
38 *#* Merge da SC: macros.h, pool.h, BIT_CHANGE, nome dei processi, etc.
40 *#* Revision 1.4 2004/08/14 18:36:50 rasky
41 *#* Doxygen fix e un livello di parentesi aggiuntivi per la macro
43 *#* Revision 1.3 2004/08/12 20:01:32 rasky
44 *#* Aggiunte macro BIT_CHANGE e BIT_CHANGE_BV
46 *#* Revision 1.2 2004/08/10 21:36:14 rasky
47 *#* Aggiunto include macros.h dove serve
48 *#* Aggiunta dipendenza da compiler.h in macros.h
50 *#* Revision 1.1 2004/08/10 21:30:00 rasky
51 *#* Estratte le funzioni macro in macros.h
60 /* Type-generic macros */
63 __typeof__(n) _n = (n); \
64 (_n < 0) ? -_n : _n; \
67 __typeof__(a) _a = (a); \
68 __typeof__(b) _b = (b); \
69 (void)(&_a == &_b); /* ensure same type */ \
70 (_a < _b) ? _a : _b; \
73 __typeof__(a) _a = (a); \
74 __typeof__(b) _b = (b); \
75 (void)(&_a == &_b); /* ensure same type */ \
76 (_a > _b) ? _a : _b; \
79 /* Buggy macros for inferior compilers. */
80 #define ABS(a) (((a) < 0) ? -(a) : (a))
81 #define MIN(a,b) (((a) < (b)) ? (a) : (b))
82 #define MAX(a,b) (((a) > (b)) ? (a) : (b))
85 /*! Bound \a x between \a min and \a max */
86 #define MINMAX(min,x,max) (MIN(MAX(min, x), max))
89 * Type-generic macro to swap a with b
91 * \note arguments are evaluated multiple times
95 (void)(&(a) == &(b)); /* type check */ \
103 /*! Convert a bit value to a binary flag */
104 #define BV(x) (1<<(x))
107 /*! Round up \a x to an even multiple of the 2's power \a pad */
108 #define ROUND2(x, pad) (((x) + ((pad) - 1)) & ~((pad) - 1))
110 //! Check if \a x is an integer power of 2
111 #define IS_POW2(x) (!(bool)((x) & ((x)-1)))
113 /*! Calculate a compile-time log2 for a uint8_t */
114 #define UINT8_LOG2(x) \
121 ((x) < 128 ? 6 : 7)))))))
123 /*! Calculate a compile-time log2 for a uint16_t */
124 #define UINT16_LOG2(x) \
125 ((x < 256) ? UINT8_LOG2(x) : UINT8_LOG2((x) >> 8) + 8)
127 /*! Calculate a compile-time log2 for a uint32_t */
128 #define UINT32_LOG2(x) \
129 ((x < 65536UL) ? UINT16_LOG2(x) : UINT16_LOG2((x) >> 16) + 16)
131 #if COMPILER_C99 || defined(__cplusplus)
132 /*! Count the number of arguments (up to 16) */
133 #define PP_COUNT(...) \
134 PP_COUNT__(__VA_ARGS__,16,15,14,13,12,11,10,9,8,7,6,5,4,3,2,1,0)
135 #define PP_COUNT__(a0,a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12,a13,a14,a15,count,...) \
139 #if COMPILER_C99 || defined(__cplusplus)
141 * \def BIT_CHANGE(reg, (mask, value), ...)
143 * This macro allows for efficient and compact bit toggling in a hardware
144 * register. It is meant to replace hand-coded cruft which toggles bits
147 * It is possible to specify an unlimited pair of (mask, value) parameters.
151 * void set_timer(bool start)
153 * BIT_CHANGE(REG_CTRL_TIMER,
154 * (TIMER_MODE, MODE_COUNT),
162 * The macro expansion will be roughly the following:
165 * REG_CTRL_TIMER = (REG_CTRL_TIMER & ~(TIMER_MODE|OVL_IRQ|CMP_IRQ|START)
166 * | (MODE_COUNT|OVL_IRQ|CMP_IRQ|(start ? START : 0));
169 * It is up to the compiler to produce the optimal code. We checked that GCC produces
170 * the best code in most cases. We preferred this expansion over the use of a block
171 * with a local variable because CodeWarrior 6.1 was not able to remove completely the
172 * allocation of the local from the stack.
174 * \note This macro is available only in C99 because it makes use of variadic macros.
175 * It would be possible to make up an implementation with a slightly different syntax
176 * for use with C90 compilers, through Boost Preprocessor.
181 * \def BIT_CHANGE_BV(reg, (bit, value), ...)
183 * Similar to BIT_CHANGE(), but get bits instead of masks (and applies BV() to convert
188 #define BIT_EXTRACT_FLAG_0(bit, value) bit
189 #define BIT_EXTRACT_FLAG_1(bit, value) BV(bit)
190 #define BIT_EXTRACT_VALUE__(bit, value) value
192 #define BIT_MASK_SINGLE__(use_bv, index, max, arg) \
193 ((index < max) ? (PP_CAT(BIT_EXTRACT_FLAG_, use_bv) arg) : 0) \
196 #define BIT_MASK_IF_SINGLE__(use_bv, index, max, arg) \
197 (((index < max) && (BIT_EXTRACT_VALUE__ arg)) ? (PP_CAT(BIT_EXTRACT_FLAG_, use_bv) arg) : 0) \
200 #define BIT_ITER__2(macro, use_bv, max, a0,a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12,a13,a14,a15, ...) \
201 (macro(use_bv, 0, max, a0) | \
202 macro(use_bv, 1, max, a1) | \
203 macro(use_bv, 2, max, a2) | \
204 macro(use_bv, 3, max, a3) | \
205 macro(use_bv, 4, max, a4) | \
206 macro(use_bv, 5, max, a5) | \
207 macro(use_bv, 6, max, a6) | \
208 macro(use_bv, 7, max, a7) | \
209 macro(use_bv, 8, max, a8) | \
210 macro(use_bv, 9, max, a9) | \
211 macro(use_bv, 10, max, a10) | \
212 macro(use_bv, 11, max, a11) | \
213 macro(use_bv, 12, max, a12) | \
214 macro(use_bv, 13, max, a13) | \
215 macro(use_bv, 14, max, a14) | \
216 macro(use_bv, 15, max, a15)) \
219 #define BIT_ITER__(macro, use_bv, ...) \
220 BIT_ITER__2(macro, use_bv, PP_COUNT(__VA_ARGS__), __VA_ARGS__, (0,1),(0,1),(0,1),(0,1),(0,1),(0,1),(0,1),(0,1),(0,1),(0,1),(0,1),(0,1),(0,1),(0,1),(0,1),(0,1)) \
223 #define BIT_MASKS__(use_bv, ...) \
224 BIT_ITER__(BIT_MASK_SINGLE__, use_bv, __VA_ARGS__)
227 #define BIT_MASKS_CONDITIONAL__(use_bv, ...) \
228 BIT_ITER__(BIT_MASK_IF_SINGLE__, use_bv, __VA_ARGS__)
231 #define BIT_CHANGE__(reg, use_bv, ...) \
232 ((reg) = ((reg) & ~BIT_MASKS__(use_bv, __VA_ARGS__)) | BIT_MASKS_CONDITIONAL__(use_bv, __VA_ARGS__)) \
235 #define BIT_CHANGE(reg, ...) BIT_CHANGE__(reg, 0, __VA_ARGS__)
236 #define BIT_CHANGE_BV(reg, ...) BIT_CHANGE__(reg, 1, __VA_ARGS__)
238 #endif /* COMPILER_C99 */
240 #endif /* MACROS_H */