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authorEric Biederman <ebiederm@xmission.com>2004-11-05 19:55:46 +0000
committerEric Biederman <ebiederm@xmission.com>2004-11-05 19:55:46 +0000
commit7a9c836f93de8373c122d483894599b3eaf4b151 (patch)
treee30622091f23ff1b66d31ad567324052dd1f6e24 /src/include/arch-generic/div64.h
parent692f2c7aed911dc193e96b214b62366ad04c89b2 (diff)
downloadcoreboot-7a9c836f93de8373c122d483894599b3eaf4b151.tar.xz
- How did I forget to cvs add this?
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@1763 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
Diffstat (limited to 'src/include/arch-generic/div64.h')
-rw-r--r--src/include/arch-generic/div64.h59
1 files changed, 59 insertions, 0 deletions
diff --git a/src/include/arch-generic/div64.h b/src/include/arch-generic/div64.h
new file mode 100644
index 0000000000..a6bc97532a
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+++ b/src/include/arch-generic/div64.h
@@ -0,0 +1,59 @@
+#ifndef ARCH_GENERIC_DIV64_H
+#define ARCH_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 <limits.h>
+#include <stdint.h>
+
+#if ULONG_MAX == 4294967295
+
+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 (likely(((n) >> 32) == 0)) { \
+ __rem = (uint32_t)(n) % __base; \
+ (n) = (uint32_t)(n) / __base; \
+ } else \
+ __rem = __div64_32(&(n), __base); \
+ __rem; \
+ })
+
+#elif ULONG_MAX == 18446744073709551615
+
+# define do_div(n,base) ({ \
+ uint32_t __base = (base); \
+ uint32_t __rem; \
+ __rem = ((uint64_t)(n)) % __base; \
+ (n) = ((uint64_t)(n)) / __base; \
+ __rem; \
+ })
+
+
+#else /* BITS_PER_LONG == ?? */
+
+# error do_div() does not yet support the C64
+
+#endif /* BITS_PER_LONG */
+
+#endif /* ARCH_GENERIC_DIV64_H */