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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 422 | giacomo | 1 | #ifndef _ASM_GENERIC_DIV64_H |
| 2 | #define _ASM_GENERIC_DIV64_H |
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| 3 | /* |
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| 4 | * Copyright (C) 2003 Bernardo Innocenti <bernie@develer.com> |
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| 5 | * Based on former asm-ppc/div64.h and asm-m68knommu/div64.h |
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| 6 | * |
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| 7 | * The semantics of do_div() are: |
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| 8 | * |
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| 9 | * uint32_t do_div(uint64_t *n, uint32_t base) |
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| 10 | * { |
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| 11 | * uint32_t remainder = *n % base; |
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| 12 | * *n = *n / base; |
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| 13 | * return remainder; |
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| 14 | * } |
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| 15 | * |
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| 16 | * NOTE: macro parameter n is evaluated multiple times, |
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| 17 | * beware of side effects! |
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| 18 | */ |
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| 19 | |||
| 20 | #include <linux/types.h> |
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| 21 | #include <linux/compiler.h> |
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| 22 | |||
| 23 | #if BITS_PER_LONG == 64 |
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| 24 | |||
| 25 | # define do_div(n,base) ({ \ |
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| 26 | uint32_t __base = (base); \ |
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| 27 | uint32_t __rem; \ |
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| 28 | __rem = ((uint64_t)(n)) % __base; \ |
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| 29 | (n) = ((uint64_t)(n)) / __base; \ |
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| 30 | __rem; \ |
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| 31 | }) |
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| 32 | |||
| 33 | #elif BITS_PER_LONG == 32 |
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| 34 | |||
| 35 | extern uint32_t __div64_32(uint64_t *dividend, uint32_t divisor); |
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| 36 | |||
| 37 | /* The unnecessary pointer compare is there |
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| 38 | * to check for type safety (n must be 64bit) |
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| 39 | */ |
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| 40 | # define do_div(n,base) ({ \ |
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| 41 | uint32_t __base = (base); \ |
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| 42 | uint32_t __rem; \ |
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| 43 | (void)(((typeof((n)) *)0) == ((uint64_t *)0)); \ |
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| 44 | if (likely(((n) >> 32) == 0)) { \ |
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| 45 | __rem = (uint32_t)(n) % __base; \ |
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| 46 | (n) = (uint32_t)(n) / __base; \ |
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| 47 | } else \ |
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| 48 | __rem = __div64_32(&(n), __base); \ |
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| 49 | __rem; \ |
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| 50 | }) |
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| 51 | |||
| 52 | #else /* BITS_PER_LONG == ?? */ |
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| 53 | |||
| 54 | # error do_div() does not yet support the C64 |
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| 55 | |||
| 56 | #endif /* BITS_PER_LONG */ |
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| 57 | |||
| 58 | #endif /* _ASM_GENERIC_DIV64_H */ |