4 * This file is part of BeRTOS.
6 * Bertos is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20 * As a special exception, you may use this file as part of a free software
21 * library without restriction. Specifically, if other files instantiate
22 * templates or use macros or inline functions from this file, or you compile
23 * this file and link it with other files to produce an executable, this
24 * file does not by itself cause the resulting executable to be covered by
25 * the GNU General Public License. This exception does not however
26 * invalidate any other reasons why the executable file might be covered by
27 * the GNU General Public License.
29 * Copyright 2003, 2004 Develer S.r.l. (http://www.develer.com/)
33 * \defgroup macros General purpose macros
37 * \brief Common and handy function macros
39 * \author Bernie Innocenti <bernie@codewiz.org>
40 * \author Giovanni Bajo <rasky@develer.com>
45 #include <cfg/compiler.h>
47 /* avr-gcc does not seem to support libstdc++ */
48 #if defined(__cplusplus) && !CPU_AVR
49 /* Type-generic macros implemented with template functions. */
52 template<class T> inline T ABS(T n) { return n >= 0 ? n : -n; }
53 #define MIN(a,b) std::min(a, b)
54 #define MAX(a,b) std::max(a, b)
55 #define SWAP(a,b) std::swap(a, b)
56 #elif (COMPILER_STATEMENT_EXPRESSIONS && COMPILER_TYPEOF)
57 /* Type-generic macros implemented with statement expressions. */
60 (_n < 0) ? -_n : _n; \
65 ASSERT_TYPE_EQUAL(_a, _b); \
67 * The (typeof(_a)) cast in necessary: \
68 * result type of conditional expressions is \
69 * *NOT* the type of the value returned but \
70 * the type that would be produced if _a and _b \
71 * were mixed in an expression. \
72 * Even in _a and _b are of the same type, \
73 * if mixed in an expression the type will be \
74 * (at least) promoted to int! \
76 ((typeof(_a))((_a < _b) ? _a : _b)); \
81 ASSERT_TYPE_EQUAL(_a, _b); \
83 * The (typeof(_a)) cast in necessary: \
84 * result type of conditional expressions is \
85 * *NOT* the type of the value returned but \
86 * the type that would be produced if _a and _b \
87 * were mixed in an expression. \
88 * Even in _a and _b are of the same type, \
89 * if mixed in an expression the type will be \
90 * (at least) promoted to int! \
92 ((typeof(_a))((_a > _b) ? _a : _b)); \
94 #else /* !(COMPILER_STATEMENT_EXPRESSIONS && COMPILER_TYPEOF) */
95 /* Buggy macros for inferior compilers. */
96 #define ABS(a) (((a) < 0) ? -(a) : (a))
97 #define MIN(a,b) (((a) < (b)) ? (a) : (b))
98 #define MAX(a,b) (((a) > (b)) ? (a) : (b))
99 #endif /* !(COMPILER_STATEMENT_EXPRESSIONS && COMPILER_TYPEOF) */
101 /** Align \p value to the next \p align boundary */
102 #define ALIGN_UP(value, align) (((value) & ((align) - 1)) ? \
103 (((value) + ((align) - 1)) & ~((align) - 1)) : \
106 /** Bound \a x between \a min and \a max. */
107 #define MINMAX(min,x,max) (MIN(MAX(min, x), max))
110 /* Use standard implementation from <algorithm> */
111 #define SWAP(a,b) std::swap(a, b)
112 #elif COMPILER_TYPEOF
114 * Type-generic macro to swap \a a with \a b.
116 * \note Arguments are evaluated multiple times.
121 ASSERT_TYPE_EQUAL(a, b); \
126 #else /* !COMPILER_TYPEOF */
127 /* Sub-optimal implementation that only works with integral types. */
135 #endif /* COMPILER_TYPEOF */
138 * Shuffle the content of \a array that counts \a len elements.
140 #define SHUFFLE(array, len) \
143 for (i = (len) - 1; i > 0; i--) \
145 j = ((i + 1) * (rand() / (RAND_MAX + 1.0))); \
146 SWAP((array)[i], (array)[j]); \
151 * Macro to swap \a a with \a b, with explicit type \a T for dumb C89 compilers.
153 * \note Arguments are evaluated multiple times.
155 #define SWAP_T(a, b, T) \
158 ASSERT_TYPE_IS(a, T); \
159 ASSERT_TYPE_IS(b, T); \
166 * Reverse the bits contained in b (LSB becomes the MSB and so on).
167 * \note \a b is evaluated twice
169 #define REVERSE_UINT8(b) \
170 ((uint8_t)((((b) * 0x0802UL & 0x22110UL) | ((b) * 0x8020UL & 0x88440UL)) * 0x10101UL >> 16))
173 /** Convert a bit value to a binary flag. */
174 #define BV(x) (1<<(x))
177 /** Same as BV() but with 32 bit result */
178 #define BV32(x) ((uint32_t)1<<(x))
180 /** Same as BV() but with 16 bit result */
181 #define BV16(x) ((uint16_t)1<<(x))
183 /** Same as BV() but with 8 bit result */
184 #define BV8(x) ((uint8_t)1<<(x))
187 * Perform an integer division rounding the result to the nearest int value.
188 * \note \a divisor should preferibly be a costant, otherwise this macro generates
189 * 2 division. Also divisor is evaluated twice.
191 #define DIV_ROUND(dividend, divisor) (((dividend) + (divisor) / 2) / (divisor))
194 * Perform an integer division rounding the result to the upper int value.
195 * \note \a divisor is evaluated twice.
197 #define DIV_ROUNDUP(dividend, divisor) (((dividend) + (divisor) - 1) / (divisor))
199 /** Round up \a x to an even multiple of the 2's power \a pad. */
200 #define ROUND_UP2(x, pad) (((x) + ((pad) - 1)) & ~((pad) - 1))
203 * \name Integer round macros.
205 * Round \a x to a multiple of \a base.
206 * \note If \a x is signed these macros generate a lot of code.
209 #define ROUND_DOWN(x, base) ( (x) - ((x) % (base)) )
210 #define ROUND_UP(x, base) ( ((x) + (base) - 1) - (((x) + (base) - 1) % (base)) )
211 #define ROUND_NEAREST(x, base) ( ((x) + (base) / 2) - (((x) + (base) / 2) % (base)) )
214 /** Check if \a x is an integer power of 2. */
215 #define IS_POW2(x) (!(bool)((x) & ((x)-1)))
217 /** Calculate a compile-time log2 for a uint8_t */
218 #define UINT8_LOG2(x) \
225 ((x) < 128 ? 6 : 7)))))))
227 /** Calculate a compile-time log2 for a uint16_t */
228 #define UINT16_LOG2(x) \
229 ((x < 256) ? UINT8_LOG2(x) : UINT8_LOG2((x) >> 8) + 8)
231 /** Calculate a compile-time log2 for a uint32_t */
232 #define UINT32_LOG2(x) \
233 ((x < 65536UL) ? UINT16_LOG2(x) : UINT16_LOG2((x) >> 16) + 16)
235 #if COMPILER_VARIADIC_MACROS
236 /** Count the number of arguments (up to 16). */
237 #define PP_COUNT(...) \
238 PP_COUNT__(__VA_ARGS__,16,15,14,13,12,11,10,9,8,7,6,5,4,3,2,1,0)
239 #define PP_COUNT__(a0,a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12,a13,a14,a15,count,...) \
243 #if COMPILER_VARIADIC_MACROS
245 * \def BIT_CHANGE(reg, (mask, value), ...)
247 * This macro allows for efficient and compact bit toggling in a hardware
248 * register. It is meant to replace hand-coded cruft which toggles bits
251 * It is possible to specify an unlimited pair of (mask, value) parameters.
255 * void set_timer(bool start)
257 * BIT_CHANGE(REG_CTRL_TIMER,
258 * (TIMER_MODE, MODE_COUNT),
266 * The macro expansion will be roughly the following:
269 * REG_CTRL_TIMER = (REG_CTRL_TIMER & ~(TIMER_MODE|OVL_IRQ|CMP_IRQ|START)
270 * | (MODE_COUNT|OVL_IRQ|CMP_IRQ|(start ? START : 0));
273 * It is up to the compiler to produce the optimal code. We checked that GCC produces
274 * the best code in most cases. We preferred this expansion over the use of a block
275 * with a local variable because CodeWarrior 6.1 was not able to remove completely the
276 * allocation of the local from the stack.
278 * \note This macro is available only in C99 because it makes use of variadic macros.
279 * It would be possible to make up an implementation with a slightly different syntax
280 * for use with C90 compilers, through Boost Preprocessor.
284 * \def BIT_CHANGE_BV(reg, (bit, value), ...)
286 * Similar to BIT_CHANGE(), but get bits instead of masks (and applies BV() to convert
290 #define BIT_EXTRACT_FLAG_0(bit, value) bit
291 #define BIT_EXTRACT_FLAG_1(bit, value) BV(bit)
292 #define BIT_EXTRACT_VALUE__(bit, value) value
294 #define BIT_MASK_SINGLE__(use_bv, index, max, arg) \
295 ((index < max) ? (PP_CAT(BIT_EXTRACT_FLAG_, use_bv) arg) : 0) \
298 #define BIT_MASK_IF_SINGLE__(use_bv, index, max, arg) \
299 (((index < max) && (BIT_EXTRACT_VALUE__ arg)) ? (PP_CAT(BIT_EXTRACT_FLAG_, use_bv) arg) : 0) \
302 #define BIT_ITER__2(macro, use_bv, max, a0,a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12,a13,a14,a15, ...) \
303 (macro(use_bv, 0, max, a0) | \
304 macro(use_bv, 1, max, a1) | \
305 macro(use_bv, 2, max, a2) | \
306 macro(use_bv, 3, max, a3) | \
307 macro(use_bv, 4, max, a4) | \
308 macro(use_bv, 5, max, a5) | \
309 macro(use_bv, 6, max, a6) | \
310 macro(use_bv, 7, max, a7) | \
311 macro(use_bv, 8, max, a8) | \
312 macro(use_bv, 9, max, a9) | \
313 macro(use_bv, 10, max, a10) | \
314 macro(use_bv, 11, max, a11) | \
315 macro(use_bv, 12, max, a12) | \
316 macro(use_bv, 13, max, a13) | \
317 macro(use_bv, 14, max, a14) | \
318 macro(use_bv, 15, max, a15)) \
321 #define BIT_ITER__(macro, use_bv, ...) \
322 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)) \
325 #define BIT_MASKS__(use_bv, ...) \
326 BIT_ITER__(BIT_MASK_SINGLE__, use_bv, __VA_ARGS__)
329 #define BIT_MASKS_CONDITIONAL__(use_bv, ...) \
330 BIT_ITER__(BIT_MASK_IF_SINGLE__, use_bv, __VA_ARGS__)
333 #define BIT_CHANGE__(reg, use_bv, ...) \
334 ((reg) = ((reg) & ~BIT_MASKS__(use_bv, __VA_ARGS__)) | BIT_MASKS_CONDITIONAL__(use_bv, __VA_ARGS__)) \
337 #define BIT_CHANGE(reg, ...) BIT_CHANGE__(reg, 0, __VA_ARGS__)
338 #define BIT_CHANGE_BV(reg, ...) BIT_CHANGE__(reg, 1, __VA_ARGS__)
340 #endif /* COMPILER_VARIADIC_MACROS */
343 * Macro for rotating bit left or right.
346 #define ROTR(var, rot) (((var) >> (rot)) | ((var) << ((sizeof(var) * 8) - (rot))))
347 #define ROTL(var, rot) (((var) << (rot)) | ((var) >> ((sizeof(var) * 8) - (rot))))
351 * Make an id from 4 letters, useful for
352 * file formats and kfile ids.
354 #define MAKE_ID(a,b,c,d) \
355 ( ((uint32_t)(a) << 24) \
356 | ((uint32_t)(b) << 16) \
357 | ((uint32_t)(c) << 8) \
358 | ((uint32_t)(d) << 0) )
361 * Type for id generated by MAKE_ID().
363 typedef uint32_t id_t;
365 /** \} */ //defgroup macros
367 #endif /* MACROS_H */