#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! */ #ifndef ULONG_MAX #include <limits.h> #endif #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 (((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 */