1 #ifndef ARCH_GENERIC_DIV64_H
2 #define ARCH_GENERIC_DIV64_H
4 * Copyright (C) 2003 Bernardo Innocenti <bernie@develer.com>
5 * Based on former asm-ppc/div64.h and asm-m68knommu/div64.h
7 * The semantics of do_div() are:
9 * uint32_t do_div(uint64_t *n, uint32_t base)
11 * uint32_t remainder = *n % base;
16 * NOTE: macro parameter n is evaluated multiple times,
17 * beware of side effects!
25 #if ULONG_MAX == 4294967295
27 extern uint32_t __div64_32(uint64_t *dividend, uint32_t divisor);
29 /* The unnecessary pointer compare is there
30 * to check for type safety (n must be 64bit)
32 # define do_div(n,base) ({ \
33 uint32_t __base = (base); \
35 (void)(((typeof((n)) *)0) == ((uint64_t *)0)); \
36 if (((n) >> 32) == 0) { \
37 __rem = (uint32_t)(n) % __base; \
38 (n) = (uint32_t)(n) / __base; \
40 __rem = __div64_32(&(n), __base); \
44 #elif ULONG_MAX == 18446744073709551615
46 # define do_div(n,base) ({ \
47 uint32_t __base = (base); \
49 __rem = ((uint64_t)(n)) % __base; \
50 (n) = ((uint64_t)(n)) / __base; \
55 #else /* BITS_PER_LONG == ?? */
57 # error do_div() does not yet support the C64
59 #endif /* BITS_PER_LONG */
61 #endif /* ARCH_GENERIC_DIV64_H */