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authorDirk Behme <dirk.behme@googlemail.com>2007-08-02 17:41:14 +0200
committerWolfgang Denk <wd@denx.de>2007-08-10 10:33:34 +0200
commitf7c086e94e8ce9aad7268af97f73aa6884686f27 (patch)
treef6027f3aa957584b779daeb26efba7326630a8e8 /include/div64.h
parenta22806469a8f2b69c829f4fd5361fdebd0cb01b4 (diff)
Move 64bit division from avr32 to generic lib
Move the 64bit division from lib_avr32 to lib_generic. With this, all boards can do_div/__div64_32 if needed, not only avr one. Code is put to lib_generic, so no larger memory footprint if not used. No code modifications. Thanks for proposal by HÃ¥vard Skinnemoen. Signed-off-by: Dirk Behme <dirk.behme@gmail.com>
Diffstat (limited to 'include/div64.h')
-rw-r--r--include/div64.h39
1 files changed, 39 insertions, 0 deletions
diff --git a/include/div64.h b/include/div64.h
new file mode 100644
index 000000000..2e0ba8389
--- /dev/null
+++ b/include/div64.h
@@ -0,0 +1,39 @@
+#ifndef _ASM_GENERIC_DIV64_H
+#define _ASM_GENERIC_DIV64_H
+/*
+ * Copyright (C) 2003 Bernardo Innocenti <bernie@develer.com>
+ * Based on former asm-ppc/div64.h and asm-m68knommu/div64.h
+ *
+ * The semantics of do_div() are:
+ *
+ * uint32_t do_div(uint64_t *n, uint32_t base)
+ * {
+ * uint32_t remainder = *n % base;
+ * *n = *n / base;
+ * return remainder;
+ * }
+ *
+ * NOTE: macro parameter n is evaluated multiple times,
+ * beware of side effects!
+ */
+
+#include <linux/types.h>
+
+extern uint32_t __div64_32(uint64_t *dividend, uint32_t divisor);
+
+/* The unnecessary pointer compare is there
+ * to check for type safety (n must be 64bit)
+ */
+# define do_div(n,base) ({ \
+ uint32_t __base = (base); \
+ uint32_t __rem; \
+ (void)(((typeof((n)) *)0) == ((uint64_t *)0)); \
+ if (((n) >> 32) == 0) { \
+ __rem = (uint32_t)(n) % __base; \
+ (n) = (uint32_t)(n) / __base; \
+ } else \
+ __rem = __div64_32(&(n), __base); \
+ __rem; \
+ })
+
+#endif /* _ASM_GENERIC_DIV64_H */