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| Commit | Line | Data |
|---|---|---|
| 1da177e4 LT |
1 | #ifndef _ASM_GENERIC_DIV64_H |
| 2 | #define _ASM_GENERIC_DIV64_H | |
| 3 | /* | |
| 4 | * Copyright (C) 2003 Bernardo Innocenti <[email protected]> | |
| 5 | * Based on former asm-ppc/div64.h and asm-m68knommu/div64.h | |
| 6 | * | |
| 7 | * The semantics of do_div() are: | |
| 8 | * | |
| 9 | * uint32_t do_div(uint64_t *n, uint32_t base) | |
| 10 | * { | |
| 11 | * uint32_t remainder = *n % base; | |
| 12 | * *n = *n / base; | |
| 13 | * return remainder; | |
| 14 | * } | |
| 15 | * | |
| 16 | * NOTE: macro parameter n is evaluated multiple times, | |
| 17 | * beware of side effects! | |
| 18 | */ | |
| 19 | ||
| 20 | #include <linux/types.h> | |
| 21 | #include <linux/compiler.h> | |
| 22 | ||
| 23 | #if BITS_PER_LONG == 64 | |
| 24 | ||
| 25 | # define do_div(n,base) ({ \ | |
| 26 | uint32_t __base = (base); \ | |
| 27 | uint32_t __rem; \ | |
| 28 | __rem = ((uint64_t)(n)) % __base; \ | |
| 29 | (n) = ((uint64_t)(n)) / __base; \ | |
| 30 | __rem; \ | |
| 31 | }) | |
| 32 | ||
| 33 | #elif BITS_PER_LONG == 32 | |
| 34 | ||
| 35 | extern uint32_t __div64_32(uint64_t *dividend, uint32_t divisor); | |
| 36 | ||
| 37 | /* The unnecessary pointer compare is there | |
| 38 | * to check for type safety (n must be 64bit) | |
| 39 | */ | |
| 40 | # define do_div(n,base) ({ \ | |
| 41 | uint32_t __base = (base); \ | |
| 42 | uint32_t __rem; \ | |
| 43 | (void)(((typeof((n)) *)0) == ((uint64_t *)0)); \ | |
| 44 | if (likely(((n) >> 32) == 0)) { \ | |
| 45 | __rem = (uint32_t)(n) % __base; \ | |
| 46 | (n) = (uint32_t)(n) / __base; \ | |
| 47 | } else \ | |
| 48 | __rem = __div64_32(&(n), __base); \ | |
| 49 | __rem; \ | |
| 50 | }) | |
| 51 | ||
| 52 | #else /* BITS_PER_LONG == ?? */ | |
| 53 | ||
| 54 | # error do_div() does not yet support the C64 | |
| 55 | ||
| 56 | #endif /* BITS_PER_LONG */ | |
| 57 | ||
| 58 | #endif /* _ASM_GENERIC_DIV64_H */ |