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 1.4 2005/07/03 15:19:09 bernie
20 *#* Revision 1.3 2005/06/27 21:23:32 bernie
21 *#* ROUND_DOWN, ROUND_UP, ROUND_NEAREST: New macros.
23 *#* Revision 1.2 2005/04/11 19:10:27 bernie
24 *#* Include top-level headers from cfg/ subdir.
26 *#* Revision 1.1 2005/04/11 19:04:13 bernie
27 *#* Move top-level headers to cfg/ subdir.
29 *#* Revision 1.10 2005/01/22 04:19:50 bernie
30 *#* Use non-uglified typeof().
32 *#* Revision 1.9 2004/12/08 08:51:34 bernie
33 *#* Add type-generic macros for C++.
35 *#* Revision 1.8 2004/10/19 07:14:20 bernie
36 *#* Add macros to test for specific compiler features.
38 *#* Revision 1.7 2004/09/20 03:30:45 bernie
39 *#* C++ also has variadic macros.
41 *#* Revision 1.6 2004/09/14 21:02:04 bernie
42 *#* SWAP(), MINMAX(): New macros.
44 *#* Revision 1.5 2004/08/29 21:57:58 bernie
45 *#* Move back STATIC_ASSERT() to compiler.h as it's needed in cpu.h;
46 *#* iptr_t, const_iptr_t: Replace IPTR macro with a real typedef.
48 *#* Revision 1.3 2004/08/24 14:13:48 bernie
49 *#* Restore a few macros that were lost in the way.
51 *#* Revision 1.2 2004/08/24 13:32:14 bernie
52 *#* PP_CAT(), PP_STRINGIZE(): Move back to compiler.h to break circular dependency between cpu.h/compiler.h/macros.h;
53 *#* offsetof(), countof(): Move back to compiler.h to avoid including macros.h almost everywhere;
55 *#* Rename header guards;
56 *#* Don't include arch_config.h in compiler.h as it's not needed there.
58 *#* Revision 1.1 2004/08/14 19:37:57 rasky
59 *#* Merge da SC: macros.h, pool.h, BIT_CHANGE, nome dei processi, etc.
61 *#* Revision 1.4 2004/08/14 18:36:50 rasky
62 *#* Doxygen fix e un livello di parentesi aggiuntivi per la macro
64 *#* Revision 1.3 2004/08/12 20:01:32 rasky
65 *#* Aggiunte macro BIT_CHANGE e BIT_CHANGE_BV
67 *#* Revision 1.2 2004/08/10 21:36:14 rasky
68 *#* Aggiunto include macros.h dove serve
69 *#* Aggiunta dipendenza da compiler.h in macros.h
71 *#* Revision 1.1 2004/08/10 21:30:00 rasky
72 *#* Estratte le funzioni macro in macros.h
79 #include <cfg/compiler.h>
81 /* avr-gcc does not seem to support libstdc++ */
82 #if defined(__cplusplus) && !CPU_AVR
83 /* Type-generic macros implemented with template functions. */
86 template<class T> inline T ABS(T n) { return n >= 0 ? n : -n; }
87 #define MIN(a,b) std::min(a, b)
88 #define MAX(a,b) std::max(a, b)
89 #define SWAP(a,b) std::swap(a, b)
90 #elif (COMPILER_STATEMENT_EXPRESSIONS && COMPILER_TYPEOF)
91 /* Type-generic macros implemented with statement expressions. */
94 (_n < 0) ? -_n : _n; \
99 (void)(&_a == &_b); /* ensure same type */ \
100 (_a < _b) ? _a : _b; \
102 #define MAX(a,b) ({ \
103 typeof(a) _a = (a); \
104 typeof(b) _b = (b); \
105 (void)(&_a == &_b); /* ensure same type */ \
106 (_a > _b) ? _a : _b; \
108 #else /* !(COMPILER_STATEMENT_EXPRESSIONS && COMPILER_TYPEOF) */
109 /* Buggy macros for inferior compilers. */
110 #define ABS(a) (((a) < 0) ? -(a) : (a))
111 #define MIN(a,b) (((a) < (b)) ? (a) : (b))
112 #define MAX(a,b) (((a) > (b)) ? (a) : (b))
113 #endif /* !(COMPILER_STATEMENT_EXPRESSIONS && COMPILER_TYPEOF) */
115 /*! Bound \a x between \a min and \a max. */
116 #define MINMAX(min,x,max) (MIN(MAX(min, x), max))
119 /* Use standard implementation from <algorithm> */
120 #define SWAP(a,b) std::swap(a, b)
121 #elif COMPILER_TYPEOF
123 * Type-generic macro to swap \a a with \a b.
125 * \note Arguments are evaluated multiple times.
129 (void)(&(a) == &(b)); /* type check */ \
135 #else /* !COMPILER_TYPEOF */
136 /* Sub-optimal implementation that only works with integral types. */
137 #define SWAP(a, b) ((a) ^= (b) ^= (a) ^= (b))
138 #endif /* COMPILER_TYPEOF */
141 /*! Convert a bit value to a binary flag. */
142 #define BV(x) (1<<(x))
145 /*! Round up \a x to an even multiple of the 2's power \a pad */
146 #define ROUND2(x, pad) (((x) + ((pad) - 1)) & ~((pad) - 1))
149 * \name Integer round macros.
151 * Round \a x to a multiple of \a base.
152 * \note If \a x is signed these macros generate a lot of code.
155 #define ROUND_DOWN(x, base) ( (x) - ((x) % (base)) )
156 #define ROUND_UP(x, base) ( ((x) + (base) - 1) - (((x) + (base) - 1) % (base)) )
157 #define ROUND_NEAREST(x, base) ( ((x) + (base) / 2) - (((x) + (base) / 2) % (base)) )
160 //! Check if \a x is an integer power of 2
161 #define IS_POW2(x) (!(bool)((x) & ((x)-1)))
163 /*! Calculate a compile-time log2 for a uint8_t */
164 #define UINT8_LOG2(x) \
171 ((x) < 128 ? 6 : 7)))))))
173 /*! Calculate a compile-time log2 for a uint16_t */
174 #define UINT16_LOG2(x) \
175 ((x < 256) ? UINT8_LOG2(x) : UINT8_LOG2((x) >> 8) + 8)
177 /*! Calculate a compile-time log2 for a uint32_t */
178 #define UINT32_LOG2(x) \
179 ((x < 65536UL) ? UINT16_LOG2(x) : UINT16_LOG2((x) >> 16) + 16)
181 #if COMPILER_VARIADIC_MACROS
182 /*! Count the number of arguments (up to 16). */
183 #define PP_COUNT(...) \
184 PP_COUNT__(__VA_ARGS__,16,15,14,13,12,11,10,9,8,7,6,5,4,3,2,1,0)
185 #define PP_COUNT__(a0,a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12,a13,a14,a15,count,...) \
189 #if COMPILER_VARIADIC_MACROS
191 * \def BIT_CHANGE(reg, (mask, value), ...)
193 * This macro allows for efficient and compact bit toggling in a hardware
194 * register. It is meant to replace hand-coded cruft which toggles bits
197 * It is possible to specify an unlimited pair of (mask, value) parameters.
201 * void set_timer(bool start)
203 * BIT_CHANGE(REG_CTRL_TIMER,
204 * (TIMER_MODE, MODE_COUNT),
212 * The macro expansion will be roughly the following:
215 * REG_CTRL_TIMER = (REG_CTRL_TIMER & ~(TIMER_MODE|OVL_IRQ|CMP_IRQ|START)
216 * | (MODE_COUNT|OVL_IRQ|CMP_IRQ|(start ? START : 0));
219 * It is up to the compiler to produce the optimal code. We checked that GCC produces
220 * the best code in most cases. We preferred this expansion over the use of a block
221 * with a local variable because CodeWarrior 6.1 was not able to remove completely the
222 * allocation of the local from the stack.
224 * \note This macro is available only in C99 because it makes use of variadic macros.
225 * It would be possible to make up an implementation with a slightly different syntax
226 * for use with C90 compilers, through Boost Preprocessor.
230 * \def BIT_CHANGE_BV(reg, (bit, value), ...)
232 * Similar to BIT_CHANGE(), but get bits instead of masks (and applies BV() to convert
236 #define BIT_EXTRACT_FLAG_0(bit, value) bit
237 #define BIT_EXTRACT_FLAG_1(bit, value) BV(bit)
238 #define BIT_EXTRACT_VALUE__(bit, value) value
240 #define BIT_MASK_SINGLE__(use_bv, index, max, arg) \
241 ((index < max) ? (PP_CAT(BIT_EXTRACT_FLAG_, use_bv) arg) : 0) \
244 #define BIT_MASK_IF_SINGLE__(use_bv, index, max, arg) \
245 (((index < max) && (BIT_EXTRACT_VALUE__ arg)) ? (PP_CAT(BIT_EXTRACT_FLAG_, use_bv) arg) : 0) \
248 #define BIT_ITER__2(macro, use_bv, max, a0,a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12,a13,a14,a15, ...) \
249 (macro(use_bv, 0, max, a0) | \
250 macro(use_bv, 1, max, a1) | \
251 macro(use_bv, 2, max, a2) | \
252 macro(use_bv, 3, max, a3) | \
253 macro(use_bv, 4, max, a4) | \
254 macro(use_bv, 5, max, a5) | \
255 macro(use_bv, 6, max, a6) | \
256 macro(use_bv, 7, max, a7) | \
257 macro(use_bv, 8, max, a8) | \
258 macro(use_bv, 9, max, a9) | \
259 macro(use_bv, 10, max, a10) | \
260 macro(use_bv, 11, max, a11) | \
261 macro(use_bv, 12, max, a12) | \
262 macro(use_bv, 13, max, a13) | \
263 macro(use_bv, 14, max, a14) | \
264 macro(use_bv, 15, max, a15)) \
267 #define BIT_ITER__(macro, use_bv, ...) \
268 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)) \
271 #define BIT_MASKS__(use_bv, ...) \
272 BIT_ITER__(BIT_MASK_SINGLE__, use_bv, __VA_ARGS__)
275 #define BIT_MASKS_CONDITIONAL__(use_bv, ...) \
276 BIT_ITER__(BIT_MASK_IF_SINGLE__, use_bv, __VA_ARGS__)
279 #define BIT_CHANGE__(reg, use_bv, ...) \
280 ((reg) = ((reg) & ~BIT_MASKS__(use_bv, __VA_ARGS__)) | BIT_MASKS_CONDITIONAL__(use_bv, __VA_ARGS__)) \
283 #define BIT_CHANGE(reg, ...) BIT_CHANGE__(reg, 0, __VA_ARGS__)
284 #define BIT_CHANGE_BV(reg, ...) BIT_CHANGE__(reg, 1, __VA_ARGS__)
286 #endif /* COMPILER_VARIADIC_MACROS */
288 #endif /* MACROS_H */