4 * Copyright 2003, 2004 Develer S.r.l. (http://www.develer.com/)
5 * This file is part of DevLib - See devlib/README for information.
10 * \author Bernardo Innocenti <bernie@develer.com>
11 * \author Giovanni Bajo <rasky@develer.com>
13 * \brief Common and handy function macros
18 * Revision 1.3 2004/08/24 14:13:48 bernie
19 * Restore a few macros that were lost in the way.
21 * Revision 1.2 2004/08/24 13:32:14 bernie
22 * PP_CAT(), PP_STRINGIZE(): Move back to compiler.h to break circular dependency between cpu.h/compiler.h/macros.h;
23 * offsetof(), countof(): Move back to compiler.h to avoid including macros.h almost everywhere;
25 * Rename header guards;
26 * Don't include arch_config.h in compiler.h as it's not needed there.
28 * Revision 1.1 2004/08/14 19:37:57 rasky
29 * Merge da SC: macros.h, pool.h, BIT_CHANGE, nome dei processi, etc.
31 * Revision 1.4 2004/08/14 18:36:50 rasky
32 * Doxygen fix e un livello di parentesi aggiuntivi per la macro
34 * Revision 1.3 2004/08/12 20:01:32 rasky
35 * Aggiunte macro BIT_CHANGE e BIT_CHANGE_BV
37 * Revision 1.2 2004/08/10 21:36:14 rasky
38 * Aggiunto include macros.h dove serve
39 * Aggiunta dipendenza da compiler.h in macros.h
41 * Revision 1.1 2004/08/10 21:30:00 rasky
42 * Estratte le funzioni macro in macros.h
51 /* Type-generic macros */
54 __typeof__(n) _n = (n); \
55 (_n < 0) ? -_n : _n; \
58 __typeof__(a) _a = (a); \
59 __typeof__(b) _b = (b); \
60 (void)(&_a == &_b); /* ensure same type */ \
61 (_a < _b) ? _a : _b; \
64 __typeof__(a) _a = (a); \
65 __typeof__(b) _b = (b); \
66 (void)(&_a == &_b); /* ensure same type */ \
67 (_a > _b) ? _a : _b; \
70 /* Buggy macros for inferior compilers. */
71 #define ABS(a) (((a) < 0) ? -(a) : (a))
72 #define MIN(a,b) (((a) < (b)) ? (a) : (b))
73 #define MAX(a,b) (((a) > (b)) ? (a) : (b))
77 /*! Convert a bit value to a binary flag */
78 #define BV(x) (1<<(x))
81 /*! Round up \a x to an even multiple of the 2's power \a pad */
82 #define ROUND2(x, pad) (((x) + ((pad) - 1)) & ~((pad) - 1))
84 //! Check if \a x is an integer power of 2
85 #define IS_POW2(x) (!(bool)((x) & ((x)-1)))
87 /*! Calculate a compile-time log2 for a uint8_t */
88 #define UINT8_LOG2(x) \
95 ((x) < 128 ? 6 : 7)))))))
97 /*! Calculate a compile-time log2 for a uint16_t */
98 #define UINT16_LOG2(x) \
99 ((x < 256) ? UINT8_LOG2(x) : UINT8_LOG2((x) >> 8) + 8)
101 /*! Calculate a compile-time log2 for a uint32_t */
102 #define UINT32_LOG2(x) \
103 ((x < 65536UL) ? UINT16_LOG2(x) : UINT16_LOG2((x) >> 16) + 16)
106 /*! Count the number of arguments (up to 16) */
107 #define PP_COUNT(...) \
108 PP_COUNT__(__VA_ARGS__,16,15,14,13,12,11,10,9,8,7,6,5,4,3,2,1,0)
109 #define PP_COUNT__(a0,a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12,a13,a14,a15,count,...) \
113 /*! Issue a compilation error if the \a condition is false */
114 #define STATIC_ASSERT(condition) \
115 extern char PP_CAT(CT_ASSERT___, __LINE__)[(condition) ? 1 : -1]
119 * \def BIT_CHANGE(reg, (mask, value), ...)
121 * This macro allows for efficient and compact bit toggling in a hardware
122 * register. It is meant to replace hand-coded cruft which toggles bits
125 * It is possible to specify an unlimited pair of (mask, value) parameters.
129 * void set_timer(bool start)
131 * BIT_CHANGE(REG_CTRL_TIMER,
132 * (TIMER_MODE, MODE_COUNT),
140 * The macro expansion will be roughly the following:
143 * REG_CTRL_TIMER = (REG_CTRL_TIMER & ~(TIMER_MODE|OVL_IRQ|CMP_IRQ|START)
144 * | (MODE_COUNT|OVL_IRQ|CMP_IRQ|(start ? START : 0));
147 * It is up to the compiler to produce the optimal code. We checked that GCC produces
148 * the best code in most cases. We preferred this expansion over the use of a block
149 * with a local variable because CodeWarrior 6.1 was not able to remove completely the
150 * allocation of the local from the stack.
152 * \note This macro is available only in C99 because it makes use of variadic macros.
153 * It would be possible to make up an implementation with a slightly different syntax
154 * for use with C90 compilers, through Boost Preprocessor.
159 * \def BIT_CHANGE_BV(reg, (bit, value), ...)
161 * Similar to BIT_CHANGE(), but get bits instead of masks (and applies BV() to convert
166 #define BIT_EXTRACT_FLAG_0(bit, value) bit
167 #define BIT_EXTRACT_FLAG_1(bit, value) BV(bit)
168 #define BIT_EXTRACT_VALUE__(bit, value) value
170 #define BIT_MASK_SINGLE__(use_bv, index, max, arg) \
171 ((index < max) ? (PP_CAT(BIT_EXTRACT_FLAG_, use_bv) arg) : 0) \
174 #define BIT_MASK_IF_SINGLE__(use_bv, index, max, arg) \
175 (((index < max) && (BIT_EXTRACT_VALUE__ arg)) ? (PP_CAT(BIT_EXTRACT_FLAG_, use_bv) arg) : 0) \
178 #define BIT_ITER__2(macro, use_bv, max, a0,a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12,a13,a14,a15, ...) \
179 (macro(use_bv, 0, max, a0) | \
180 macro(use_bv, 1, max, a1) | \
181 macro(use_bv, 2, max, a2) | \
182 macro(use_bv, 3, max, a3) | \
183 macro(use_bv, 4, max, a4) | \
184 macro(use_bv, 5, max, a5) | \
185 macro(use_bv, 6, max, a6) | \
186 macro(use_bv, 7, max, a7) | \
187 macro(use_bv, 8, max, a8) | \
188 macro(use_bv, 9, max, a9) | \
189 macro(use_bv, 10, max, a10) | \
190 macro(use_bv, 11, max, a11) | \
191 macro(use_bv, 12, max, a12) | \
192 macro(use_bv, 13, max, a13) | \
193 macro(use_bv, 14, max, a14) | \
194 macro(use_bv, 15, max, a15)) \
197 #define BIT_ITER__(macro, use_bv, ...) \
198 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)) \
201 #define BIT_MASKS__(use_bv, ...) \
202 BIT_ITER__(BIT_MASK_SINGLE__, use_bv, __VA_ARGS__)
205 #define BIT_MASKS_CONDITIONAL__(use_bv, ...) \
206 BIT_ITER__(BIT_MASK_IF_SINGLE__, use_bv, __VA_ARGS__)
209 #define BIT_CHANGE__(reg, use_bv, ...) \
210 ((reg) = ((reg) & ~BIT_MASKS__(use_bv, __VA_ARGS__)) | BIT_MASKS_CONDITIONAL__(use_bv, __VA_ARGS__)) \
213 #define BIT_CHANGE(reg, ...) BIT_CHANGE__(reg, 0, __VA_ARGS__)
214 #define BIT_CHANGE_BV(reg, ...) BIT_CHANGE__(reg, 1, __VA_ARGS__)
216 #endif /* COMPILER_C99 */
218 #endif /* MACROS_H */