+/*!
+ * \file
+ * <!--
+ * Copyright 2003, 2004 Develer S.r.l. (http://www.develer.com/)
+ * This file is part of DevLib - See devlib/README for information.
+ * -->
+ *
+ * \version $Id$
+ *
+ * \author Bernardo Innocenti <bernie@develer.com>
+ * \author Giovanni Bajo <rasky@develer.com>
+ *
+ * \brief Common and handy function macros
+ */
+
+/*
+ * $Log$
+ * Revision 1.1 2004/08/14 19:37:57 rasky
+ * Merge da SC: macros.h, pool.h, BIT_CHANGE, nome dei processi, etc.
+ *
+ * Revision 1.4 2004/08/14 18:36:50 rasky
+ * Doxygen fix e un livello di parentesi aggiuntivi per la macro
+ *
+ * Revision 1.3 2004/08/12 20:01:32 rasky
+ * Aggiunte macro BIT_CHANGE e BIT_CHANGE_BV
+ *
+ * Revision 1.2 2004/08/10 21:36:14 rasky
+ * Aggiunto include macros.h dove serve
+ * Aggiunta dipendenza da compiler.h in macros.h
+ *
+ * Revision 1.1 2004/08/10 21:30:00 rasky
+ * Estratte le funzioni macro in macros.h
+ *
+ */
+
+#ifndef MACROS_H
+#define MACROS_H
+
+#include <compiler.h>
+
+/* Quasi-ANSI macros */
+#ifndef offsetof
+ /*! offsetof(s,m) - Return the byte offset of the member \a m in struct \a s */
+ #define offsetof(s,m) (size_t)&(((s *)0)->m)
+#endif
+#ifndef countof
+ /*! Count the number of elements in the static array \a a */
+ #define countof(a) (sizeof(a) / sizeof(*(a)))
+#endif
+
+
+/* Simple macros */
+#define ABS(a) (((a) < 0) ? -(a) : (a))
+#define MIN(a,b) (((a) < (b)) ? (a) : (b))
+#define MAX(a,b) (((a) > (b)) ? (a) : (b))
+
+#ifndef BV
+/*! Convert a bit value to a binary flag */
+#define BV(x) (1<<(x))
+#endif
+
+/*! Round up \a x to an even multiple of the 2's power \a pad */
+#define ROUND2(x, pad) (((x) + ((pad) - 1)) & ~((pad) - 1))
+
+//! Check if \a x is an integer power of 2
+#define IS_POW2(x) (!(bool)((x) & ((x)-1)))
+
+/*! Calculate a compile-time log2 for a uint8_t */
+#define UINT8_LOG2(x) \
+ ((x) < 2 ? 0 : \
+ ((x) < 4 ? 1 : \
+ ((x) < 8 ? 2 : \
+ ((x) < 16 ? 3 : \
+ ((x) < 32 ? 4 : \
+ ((x) < 64 ? 5 : \
+ ((x) < 128 ? 6 : 7)))))))
+
+/*! Calculate a compile-time log2 for a uint16_t */
+#define UINT16_LOG2(x) \
+ ((x < 256) ? UINT8_LOG2(x) : UINT8_LOG2((x) >> 8) + 8)
+
+/*! Calculate a compile-time log2 for a uint32_t */
+#define UINT32_LOG2(x) \
+ ((x < 65536UL) ? UINT16_LOG2(x) : UINT16_LOG2((x) >> 16) + 16)
+
+/*! Concatenate two different preprocessor tokens (allowing macros to expand) */
+#define PP_CAT(x,y) PP_CAT__(x,y)
+#define PP_CAT__(x,y) x ## y
+#define PP_CAT3(x,y,z) PP_CAT(PP_CAT(x,y),z)
+#define PP_CAT4(x,y,z,w) PP_CAT(PP_CAT3(x,y,z),w)
+#define PP_CAT5(x,y,z,w,j) PP_CAT(PP_CAT4(x,y,z,w),j)
+
+/*! String-ize a token (allowing macros to expand) */
+#define PP_STRINGIZE(x) PP_STRINGIZE__(x)
+#define PP_STRINGIZE__(x) #x
+
+#if COMPILER_C99
+ /*! Count the number of arguments (up to 16) */
+ #define PP_COUNT(...) \
+ PP_COUNT__(__VA_ARGS__,16,15,14,13,12,11,10,9,8,7,6,5,4,3,2,1,0)
+ #define PP_COUNT__(a0,a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12,a13,a14,a15,count,...) \
+ count
+#endif
+
+/*! Issue a compilation error if the \a condition is false */
+#define STATIC_ASSERT(condition) \
+ extern char CT_ASSERT___[(condition) ? 1 : -1]
+
+
+#if COMPILER_C99
+ /*!
+ * \def BIT_CHANGE(reg, (mask, value), ...)
+ *
+ * This macro allows for efficient and compact bit toggling in a hardware
+ * register. It is meant to replace hand-coded cruft which toggles bits
+ * in sequence.
+ *
+ * It is possible to specify an unlimited pair of (mask, value) parameters.
+ * For instance:
+ *
+ * \code
+ * void set_timer(bool start)
+ * {
+ * BIT_CHANGE(REG_CTRL_TIMER,
+ * (TIMER_MODE, MODE_COUNT),
+ * (OVL_IRQ, 1),
+ * (CMP_IRQ, 1),
+ * (START, start)
+ * );
+ * }
+ * \endcode
+ *
+ * The macro expansion will be roughly the following:
+ *
+ * \code
+ * REG_CTRL_TIMER = (REG_CTRL_TIMER & ~(TIMER_MODE|OVL_IRQ|CMP_IRQ|START)
+ * | (MODE_COUNT|OVL_IRQ|CMP_IRQ|(start ? START : 0));
+ * \endcode
+ *
+ * It is up to the compiler to produce the optimal code. We checked that GCC produces
+ * the best code in most cases. We preferred this expansion over the use of a block
+ * with a local variable because CodeWarrior 6.1 was not able to remove completely the
+ * allocation of the local from the stack.
+ *
+ * \note This macro is available only in C99 because it makes use of variadic macros.
+ * It would be possible to make up an implementation with a slightly different syntax
+ * for use with C90 compilers, through Boost Preprocessor.
+ *
+ */
+
+ /*!
+ * \def BIT_CHANGE_BV(reg, (bit, value), ...)
+ *
+ * Similar to BIT_CHANGE(), but get bits instead of masks (and applies BV() to convert
+ * them to masks).
+ *
+ */
+
+ #define BIT_EXTRACT_FLAG_0(bit, value) bit
+ #define BIT_EXTRACT_FLAG_1(bit, value) BV(bit)
+ #define BIT_EXTRACT_VALUE__(bit, value) value
+
+ #define BIT_MASK_SINGLE__(use_bv, index, max, arg) \
+ ((index < max) ? (PP_CAT(BIT_EXTRACT_FLAG_, use_bv) arg) : 0) \
+ /**/
+
+ #define BIT_MASK_IF_SINGLE__(use_bv, index, max, arg) \
+ (((index < max) && (BIT_EXTRACT_VALUE__ arg)) ? (PP_CAT(BIT_EXTRACT_FLAG_, use_bv) arg) : 0) \
+ /**/
+
+ #define BIT_ITER__2(macro, use_bv, max, a0,a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12,a13,a14,a15, ...) \
+ (macro(use_bv, 0, max, a0) | \
+ macro(use_bv, 1, max, a1) | \
+ macro(use_bv, 2, max, a2) | \
+ macro(use_bv, 3, max, a3) | \
+ macro(use_bv, 4, max, a4) | \
+ macro(use_bv, 5, max, a5) | \
+ macro(use_bv, 6, max, a6) | \
+ macro(use_bv, 7, max, a7) | \
+ macro(use_bv, 8, max, a8) | \
+ macro(use_bv, 9, max, a9) | \
+ macro(use_bv, 10, max, a10) | \
+ macro(use_bv, 11, max, a11) | \
+ macro(use_bv, 12, max, a12) | \
+ macro(use_bv, 13, max, a13) | \
+ macro(use_bv, 14, max, a14) | \
+ macro(use_bv, 15, max, a15)) \
+ /**/
+
+ #define BIT_ITER__(macro, use_bv, ...) \
+ 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)) \
+ /**/
+
+ #define BIT_MASKS__(use_bv, ...) \
+ BIT_ITER__(BIT_MASK_SINGLE__, use_bv, __VA_ARGS__)
+ /**/
+
+ #define BIT_MASKS_CONDITIONAL__(use_bv, ...) \
+ BIT_ITER__(BIT_MASK_IF_SINGLE__, use_bv, __VA_ARGS__)
+ /**/
+
+ #define BIT_CHANGE__(reg, use_bv, ...) \
+ ((reg) = ((reg) & ~BIT_MASKS__(use_bv, __VA_ARGS__)) | BIT_MASKS_CONDITIONAL__(use_bv, __VA_ARGS__)) \
+ /**/
+
+ #define BIT_CHANGE(reg, ...) BIT_CHANGE__(reg, 0, __VA_ARGS__)
+ #define BIT_CHANGE_BV(reg, ...) BIT_CHANGE__(reg, 1, __VA_ARGS__)
+
+#endif /* COMPILER_C99 */
+
+#endif /* MACROS_H */
+