4 * Copyright 2003, 2004 Develer S.r.l. (http://www.develer.com/)
5 * This file is part of DevLib - See README.devlib 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 1.9 2006/07/19 12:56:25 bernie
18 *#* Convert to new Doxygen style.
20 *#* Revision 1.8 2006/03/13 02:06:55 bernie
21 *#* ROUND_UP2: Rename from ROUND2.
23 *#* Revision 1.7 2006/02/20 14:34:58 bernie
24 *#* Use portable type checking.
26 *#* Revision 1.6 2006/02/10 12:36:57 bernie
27 *#* Pacify IAR warnings for side-effects.
29 *#* Revision 1.5 2005/11/04 16:20:01 bernie
30 *#* Fix reference to README.devlib in header.
32 *#* Revision 1.4 2005/07/03 15:19:09 bernie
35 *#* Revision 1.3 2005/06/27 21:23:32 bernie
36 *#* ROUND_DOWN, ROUND_UP, ROUND_NEAREST: New macros.
38 *#* Revision 1.2 2005/04/11 19:10:27 bernie
39 *#* Include top-level headers from cfg/ subdir.
41 *#* Revision 1.1 2005/04/11 19:04:13 bernie
42 *#* Move top-level headers to cfg/ subdir.
44 *#* Revision 1.10 2005/01/22 04:19:50 bernie
45 *#* Use non-uglified typeof().
47 *#* Revision 1.9 2004/12/08 08:51:34 bernie
48 *#* Add type-generic macros for C++.
50 *#* Revision 1.8 2004/10/19 07:14:20 bernie
51 *#* Add macros to test for specific compiler features.
53 *#* Revision 1.7 2004/09/20 03:30:45 bernie
54 *#* C++ also has variadic macros.
56 *#* Revision 1.6 2004/09/14 21:02:04 bernie
57 *#* SWAP(), MINMAX(): New macros.
59 *#* Revision 1.5 2004/08/29 21:57:58 bernie
60 *#* Move back STATIC_ASSERT() to compiler.h as it's needed in cpu.h;
61 *#* iptr_t, const_iptr_t: Replace IPTR macro with a real typedef.
63 *#* Revision 1.3 2004/08/24 14:13:48 bernie
64 *#* Restore a few macros that were lost in the way.
66 *#* Revision 1.2 2004/08/24 13:32:14 bernie
67 *#* PP_CAT(), PP_STRINGIZE(): Move back to compiler.h to break circular dependency between cpu.h/compiler.h/macros.h;
68 *#* offsetof(), countof(): Move back to compiler.h to avoid including macros.h almost everywhere;
70 *#* Rename header guards;
71 *#* Don't include arch_config.h in compiler.h as it's not needed there.
73 *#* Revision 1.1 2004/08/14 19:37:57 rasky
74 *#* Merge da SC: macros.h, pool.h, BIT_CHANGE, nome dei processi, etc.
76 *#* Revision 1.4 2004/08/14 18:36:50 rasky
77 *#* Doxygen fix e un livello di parentesi aggiuntivi per la macro
79 *#* Revision 1.3 2004/08/12 20:01:32 rasky
80 *#* Aggiunte macro BIT_CHANGE e BIT_CHANGE_BV
82 *#* Revision 1.2 2004/08/10 21:36:14 rasky
83 *#* Aggiunto include macros.h dove serve
84 *#* Aggiunta dipendenza da compiler.h in macros.h
86 *#* Revision 1.1 2004/08/10 21:30:00 rasky
87 *#* Estratte le funzioni macro in macros.h
94 #include <cfg/compiler.h>
96 /* avr-gcc does not seem to support libstdc++ */
97 #if defined(__cplusplus) && !CPU_AVR
98 /* Type-generic macros implemented with template functions. */
101 template<class T> inline T ABS(T n) { return n >= 0 ? n : -n; }
102 #define MIN(a,b) std::min(a, b)
103 #define MAX(a,b) std::max(a, b)
104 #define SWAP(a,b) std::swap(a, b)
105 #elif (COMPILER_STATEMENT_EXPRESSIONS && COMPILER_TYPEOF)
106 /* Type-generic macros implemented with statement expressions. */
108 typeof(n) _n = (n); \
109 (_n < 0) ? -_n : _n; \
111 #define MIN(a,b) ({ \
112 typeof(a) _a = (a); \
113 typeof(b) _b = (b); \
114 ASSERT_TYPE_EQUAL(_a, _b); \
115 (_a < _b) ? _a : _b; \
117 #define MAX(a,b) ({ \
118 typeof(a) _a = (a); \
119 typeof(b) _b = (b); \
120 ASSERT_TYPE_EQUAL(_a, _b); \
121 (_a > _b) ? _a : _b; \
123 #else /* !(COMPILER_STATEMENT_EXPRESSIONS && COMPILER_TYPEOF) */
124 /* Buggy macros for inferior compilers. */
125 #define ABS(a) (((a) < 0) ? -(a) : (a))
126 #define MIN(a,b) (((a) < (b)) ? (a) : (b))
127 #define MAX(a,b) (((a) > (b)) ? (a) : (b))
128 #endif /* !(COMPILER_STATEMENT_EXPRESSIONS && COMPILER_TYPEOF) */
130 /** Bound \a x between \a min and \a max. */
131 #define MINMAX(min,x,max) (MIN(MAX(min, x), max))
134 /* Use standard implementation from <algorithm> */
135 #define SWAP(a,b) std::swap(a, b)
136 #elif COMPILER_TYPEOF
138 * Type-generic macro to swap \a a with \a b.
140 * \note Arguments are evaluated multiple times.
145 ASSERT_TYPE_EQUAL(a, b); \
150 #else /* !COMPILER_TYPEOF */
151 /* Sub-optimal implementation that only works with integral types. */
159 #endif /* COMPILER_TYPEOF */
162 /** Convert a bit value to a binary flag. */
163 #define BV(x) (1<<(x))
166 /** Round up \a x to an even multiple of the 2's power \a pad. */
167 #define ROUND_UP2(x, pad) (((x) + ((pad) - 1)) & ~((pad) - 1))
170 #define ROUND2 ROUND_UP2
173 * \name Integer round macros.
175 * Round \a x to a multiple of \a base.
176 * \note If \a x is signed these macros generate a lot of code.
179 #define ROUND_DOWN(x, base) ( (x) - ((x) % (base)) )
180 #define ROUND_UP(x, base) ( ((x) + (base) - 1) - (((x) + (base) - 1) % (base)) )
181 #define ROUND_NEAREST(x, base) ( ((x) + (base) / 2) - (((x) + (base) / 2) % (base)) )
184 /** Check if \a x is an integer power of 2. */
185 #define IS_POW2(x) (!(bool)((x) & ((x)-1)))
187 /** Calculate a compile-time log2 for a uint8_t */
188 #define UINT8_LOG2(x) \
195 ((x) < 128 ? 6 : 7)))))))
197 /** Calculate a compile-time log2 for a uint16_t */
198 #define UINT16_LOG2(x) \
199 ((x < 256) ? UINT8_LOG2(x) : UINT8_LOG2((x) >> 8) + 8)
201 /** Calculate a compile-time log2 for a uint32_t */
202 #define UINT32_LOG2(x) \
203 ((x < 65536UL) ? UINT16_LOG2(x) : UINT16_LOG2((x) >> 16) + 16)
205 #if COMPILER_VARIADIC_MACROS
206 /** Count the number of arguments (up to 16). */
207 #define PP_COUNT(...) \
208 PP_COUNT__(__VA_ARGS__,16,15,14,13,12,11,10,9,8,7,6,5,4,3,2,1,0)
209 #define PP_COUNT__(a0,a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12,a13,a14,a15,count,...) \
213 #if COMPILER_VARIADIC_MACROS
215 * \def BIT_CHANGE(reg, (mask, value), ...)
217 * This macro allows for efficient and compact bit toggling in a hardware
218 * register. It is meant to replace hand-coded cruft which toggles bits
221 * It is possible to specify an unlimited pair of (mask, value) parameters.
225 * void set_timer(bool start)
227 * BIT_CHANGE(REG_CTRL_TIMER,
228 * (TIMER_MODE, MODE_COUNT),
236 * The macro expansion will be roughly the following:
239 * REG_CTRL_TIMER = (REG_CTRL_TIMER & ~(TIMER_MODE|OVL_IRQ|CMP_IRQ|START)
240 * | (MODE_COUNT|OVL_IRQ|CMP_IRQ|(start ? START : 0));
243 * It is up to the compiler to produce the optimal code. We checked that GCC produces
244 * the best code in most cases. We preferred this expansion over the use of a block
245 * with a local variable because CodeWarrior 6.1 was not able to remove completely the
246 * allocation of the local from the stack.
248 * \note This macro is available only in C99 because it makes use of variadic macros.
249 * It would be possible to make up an implementation with a slightly different syntax
250 * for use with C90 compilers, through Boost Preprocessor.
254 * \def BIT_CHANGE_BV(reg, (bit, value), ...)
256 * Similar to BIT_CHANGE(), but get bits instead of masks (and applies BV() to convert
260 #define BIT_EXTRACT_FLAG_0(bit, value) bit
261 #define BIT_EXTRACT_FLAG_1(bit, value) BV(bit)
262 #define BIT_EXTRACT_VALUE__(bit, value) value
264 #define BIT_MASK_SINGLE__(use_bv, index, max, arg) \
265 ((index < max) ? (PP_CAT(BIT_EXTRACT_FLAG_, use_bv) arg) : 0) \
268 #define BIT_MASK_IF_SINGLE__(use_bv, index, max, arg) \
269 (((index < max) && (BIT_EXTRACT_VALUE__ arg)) ? (PP_CAT(BIT_EXTRACT_FLAG_, use_bv) arg) : 0) \
272 #define BIT_ITER__2(macro, use_bv, max, a0,a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12,a13,a14,a15, ...) \
273 (macro(use_bv, 0, max, a0) | \
274 macro(use_bv, 1, max, a1) | \
275 macro(use_bv, 2, max, a2) | \
276 macro(use_bv, 3, max, a3) | \
277 macro(use_bv, 4, max, a4) | \
278 macro(use_bv, 5, max, a5) | \
279 macro(use_bv, 6, max, a6) | \
280 macro(use_bv, 7, max, a7) | \
281 macro(use_bv, 8, max, a8) | \
282 macro(use_bv, 9, max, a9) | \
283 macro(use_bv, 10, max, a10) | \
284 macro(use_bv, 11, max, a11) | \
285 macro(use_bv, 12, max, a12) | \
286 macro(use_bv, 13, max, a13) | \
287 macro(use_bv, 14, max, a14) | \
288 macro(use_bv, 15, max, a15)) \
291 #define BIT_ITER__(macro, use_bv, ...) \
292 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)) \
295 #define BIT_MASKS__(use_bv, ...) \
296 BIT_ITER__(BIT_MASK_SINGLE__, use_bv, __VA_ARGS__)
299 #define BIT_MASKS_CONDITIONAL__(use_bv, ...) \
300 BIT_ITER__(BIT_MASK_IF_SINGLE__, use_bv, __VA_ARGS__)
303 #define BIT_CHANGE__(reg, use_bv, ...) \
304 ((reg) = ((reg) & ~BIT_MASKS__(use_bv, __VA_ARGS__)) | BIT_MASKS_CONDITIONAL__(use_bv, __VA_ARGS__)) \
307 #define BIT_CHANGE(reg, ...) BIT_CHANGE__(reg, 0, __VA_ARGS__)
308 #define BIT_CHANGE_BV(reg, ...) BIT_CHANGE__(reg, 1, __VA_ARGS__)
310 #endif /* COMPILER_VARIADIC_MACROS */
312 #endif /* MACROS_H */