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 1.1 2004/08/14 19:37:57 rasky
19 * Merge da SC: macros.h, pool.h, BIT_CHANGE, nome dei processi, etc.
21 * Revision 1.4 2004/08/14 18:36:50 rasky
22 * Doxygen fix e un livello di parentesi aggiuntivi per la macro
24 * Revision 1.3 2004/08/12 20:01:32 rasky
25 * Aggiunte macro BIT_CHANGE e BIT_CHANGE_BV
27 * Revision 1.2 2004/08/10 21:36:14 rasky
28 * Aggiunto include macros.h dove serve
29 * Aggiunta dipendenza da compiler.h in macros.h
31 * Revision 1.1 2004/08/10 21:30:00 rasky
32 * Estratte le funzioni macro in macros.h
41 /* Quasi-ANSI macros */
43 /*! offsetof(s,m) - Return the byte offset of the member \a m in struct \a s */
44 #define offsetof(s,m) (size_t)&(((s *)0)->m)
47 /*! Count the number of elements in the static array \a a */
48 #define countof(a) (sizeof(a) / sizeof(*(a)))
53 #define ABS(a) (((a) < 0) ? -(a) : (a))
54 #define MIN(a,b) (((a) < (b)) ? (a) : (b))
55 #define MAX(a,b) (((a) > (b)) ? (a) : (b))
58 /*! Convert a bit value to a binary flag */
59 #define BV(x) (1<<(x))
62 /*! Round up \a x to an even multiple of the 2's power \a pad */
63 #define ROUND2(x, pad) (((x) + ((pad) - 1)) & ~((pad) - 1))
65 //! Check if \a x is an integer power of 2
66 #define IS_POW2(x) (!(bool)((x) & ((x)-1)))
68 /*! Calculate a compile-time log2 for a uint8_t */
69 #define UINT8_LOG2(x) \
76 ((x) < 128 ? 6 : 7)))))))
78 /*! Calculate a compile-time log2 for a uint16_t */
79 #define UINT16_LOG2(x) \
80 ((x < 256) ? UINT8_LOG2(x) : UINT8_LOG2((x) >> 8) + 8)
82 /*! Calculate a compile-time log2 for a uint32_t */
83 #define UINT32_LOG2(x) \
84 ((x < 65536UL) ? UINT16_LOG2(x) : UINT16_LOG2((x) >> 16) + 16)
86 /*! Concatenate two different preprocessor tokens (allowing macros to expand) */
87 #define PP_CAT(x,y) PP_CAT__(x,y)
88 #define PP_CAT__(x,y) x ## y
89 #define PP_CAT3(x,y,z) PP_CAT(PP_CAT(x,y),z)
90 #define PP_CAT4(x,y,z,w) PP_CAT(PP_CAT3(x,y,z),w)
91 #define PP_CAT5(x,y,z,w,j) PP_CAT(PP_CAT4(x,y,z,w),j)
93 /*! String-ize a token (allowing macros to expand) */
94 #define PP_STRINGIZE(x) PP_STRINGIZE__(x)
95 #define PP_STRINGIZE__(x) #x
98 /*! Count the number of arguments (up to 16) */
99 #define PP_COUNT(...) \
100 PP_COUNT__(__VA_ARGS__,16,15,14,13,12,11,10,9,8,7,6,5,4,3,2,1,0)
101 #define PP_COUNT__(a0,a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12,a13,a14,a15,count,...) \
105 /*! Issue a compilation error if the \a condition is false */
106 #define STATIC_ASSERT(condition) \
107 extern char CT_ASSERT___[(condition) ? 1 : -1]
112 * \def BIT_CHANGE(reg, (mask, value), ...)
114 * This macro allows for efficient and compact bit toggling in a hardware
115 * register. It is meant to replace hand-coded cruft which toggles bits
118 * It is possible to specify an unlimited pair of (mask, value) parameters.
122 * void set_timer(bool start)
124 * BIT_CHANGE(REG_CTRL_TIMER,
125 * (TIMER_MODE, MODE_COUNT),
133 * The macro expansion will be roughly the following:
136 * REG_CTRL_TIMER = (REG_CTRL_TIMER & ~(TIMER_MODE|OVL_IRQ|CMP_IRQ|START)
137 * | (MODE_COUNT|OVL_IRQ|CMP_IRQ|(start ? START : 0));
140 * It is up to the compiler to produce the optimal code. We checked that GCC produces
141 * the best code in most cases. We preferred this expansion over the use of a block
142 * with a local variable because CodeWarrior 6.1 was not able to remove completely the
143 * allocation of the local from the stack.
145 * \note This macro is available only in C99 because it makes use of variadic macros.
146 * It would be possible to make up an implementation with a slightly different syntax
147 * for use with C90 compilers, through Boost Preprocessor.
152 * \def BIT_CHANGE_BV(reg, (bit, value), ...)
154 * Similar to BIT_CHANGE(), but get bits instead of masks (and applies BV() to convert
159 #define BIT_EXTRACT_FLAG_0(bit, value) bit
160 #define BIT_EXTRACT_FLAG_1(bit, value) BV(bit)
161 #define BIT_EXTRACT_VALUE__(bit, value) value
163 #define BIT_MASK_SINGLE__(use_bv, index, max, arg) \
164 ((index < max) ? (PP_CAT(BIT_EXTRACT_FLAG_, use_bv) arg) : 0) \
167 #define BIT_MASK_IF_SINGLE__(use_bv, index, max, arg) \
168 (((index < max) && (BIT_EXTRACT_VALUE__ arg)) ? (PP_CAT(BIT_EXTRACT_FLAG_, use_bv) arg) : 0) \
171 #define BIT_ITER__2(macro, use_bv, max, a0,a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12,a13,a14,a15, ...) \
172 (macro(use_bv, 0, max, a0) | \
173 macro(use_bv, 1, max, a1) | \
174 macro(use_bv, 2, max, a2) | \
175 macro(use_bv, 3, max, a3) | \
176 macro(use_bv, 4, max, a4) | \
177 macro(use_bv, 5, max, a5) | \
178 macro(use_bv, 6, max, a6) | \
179 macro(use_bv, 7, max, a7) | \
180 macro(use_bv, 8, max, a8) | \
181 macro(use_bv, 9, max, a9) | \
182 macro(use_bv, 10, max, a10) | \
183 macro(use_bv, 11, max, a11) | \
184 macro(use_bv, 12, max, a12) | \
185 macro(use_bv, 13, max, a13) | \
186 macro(use_bv, 14, max, a14) | \
187 macro(use_bv, 15, max, a15)) \
190 #define BIT_ITER__(macro, use_bv, ...) \
191 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)) \
194 #define BIT_MASKS__(use_bv, ...) \
195 BIT_ITER__(BIT_MASK_SINGLE__, use_bv, __VA_ARGS__)
198 #define BIT_MASKS_CONDITIONAL__(use_bv, ...) \
199 BIT_ITER__(BIT_MASK_IF_SINGLE__, use_bv, __VA_ARGS__)
202 #define BIT_CHANGE__(reg, use_bv, ...) \
203 ((reg) = ((reg) & ~BIT_MASKS__(use_bv, __VA_ARGS__)) | BIT_MASKS_CONDITIONAL__(use_bv, __VA_ARGS__)) \
206 #define BIT_CHANGE(reg, ...) BIT_CHANGE__(reg, 0, __VA_ARGS__)
207 #define BIT_CHANGE_BV(reg, ...) BIT_CHANGE__(reg, 1, __VA_ARGS__)
209 #endif /* COMPILER_C99 */
211 #endif /* MACROS_H */