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Diffstat (limited to 'include/asm-mn10300/div64.h')
| -rw-r--r-- | include/asm-mn10300/div64.h | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/include/asm-mn10300/div64.h b/include/asm-mn10300/div64.h new file mode 100644 index 000000000000..bf9c515a998c --- /dev/null +++ b/include/asm-mn10300/div64.h | |||
| @@ -0,0 +1,103 @@ | |||
| 1 | /* MN10300 64-bit division | ||
| 2 | * | ||
| 3 | * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. | ||
| 4 | * Written by David Howells (dhowells@redhat.com) | ||
| 5 | * | ||
| 6 | * This program is free software; you can redistribute it and/or | ||
| 7 | * modify it under the terms of the GNU General Public Licence | ||
| 8 | * as published by the Free Software Foundation; either version | ||
| 9 | * 2 of the Licence, or (at your option) any later version. | ||
| 10 | */ | ||
| 11 | #ifndef _ASM_DIV64 | ||
| 12 | #define _ASM_DIV64 | ||
| 13 | |||
| 14 | #include <linux/types.h> | ||
| 15 | |||
| 16 | extern void ____unhandled_size_in_do_div___(void); | ||
| 17 | |||
| 18 | /* | ||
| 19 | * divide n by base, leaving the result in n and returning the remainder | ||
| 20 | * - we can do this quite efficiently on the MN10300 by cascading the divides | ||
| 21 | * through the MDR register | ||
| 22 | */ | ||
| 23 | #define do_div(n, base) \ | ||
| 24 | ({ \ | ||
| 25 | unsigned __rem = 0; \ | ||
| 26 | if (sizeof(n) <= 4) { \ | ||
| 27 | asm("mov %1,mdr \n" \ | ||
| 28 | "divu %2,%0 \n" \ | ||
| 29 | "mov mdr,%1 \n" \ | ||
| 30 | : "+r"(n), "=d"(__rem) \ | ||
| 31 | : "r"(base), "1"(__rem) \ | ||
| 32 | : "cc" \ | ||
| 33 | ); \ | ||
| 34 | } else if (sizeof(n) <= 8) { \ | ||
| 35 | union { \ | ||
| 36 | unsigned long long l; \ | ||
| 37 | u32 w[2]; \ | ||
| 38 | } __quot; \ | ||
| 39 | __quot.l = n; \ | ||
| 40 | asm("mov %0,mdr \n" /* MDR = 0 */ \ | ||
| 41 | "divu %3,%1 \n" \ | ||
| 42 | /* __quot.MSL = __div.MSL / base, */ \ | ||
| 43 | /* MDR = MDR:__div.MSL % base */ \ | ||
| 44 | "divu %3,%2 \n" \ | ||
| 45 | /* __quot.LSL = MDR:__div.LSL / base, */ \ | ||
| 46 | /* MDR = MDR:__div.LSL % base */ \ | ||
| 47 | "mov mdr,%0 \n" \ | ||
| 48 | : "=d"(__rem), "=r"(__quot.w[1]), "=r"(__quot.w[0]) \ | ||
| 49 | : "r"(base), "0"(__rem), "1"(__quot.w[1]), \ | ||
| 50 | "2"(__quot.w[0]) \ | ||
| 51 | : "cc" \ | ||
| 52 | ); \ | ||
| 53 | n = __quot.l; \ | ||
| 54 | } else { \ | ||
| 55 | ____unhandled_size_in_do_div___(); \ | ||
| 56 | } \ | ||
| 57 | __rem; \ | ||
| 58 | }) | ||
| 59 | |||
| 60 | /* | ||
| 61 | * do an unsigned 32-bit multiply and divide with intermediate 64-bit product | ||
| 62 | * so as not to lose accuracy | ||
| 63 | * - we use the MDR register to hold the MSW of the product | ||
| 64 | */ | ||
| 65 | static inline __attribute__((const)) | ||
| 66 | unsigned __muldiv64u(unsigned val, unsigned mult, unsigned div) | ||
| 67 | { | ||
| 68 | unsigned result; | ||
| 69 | |||
| 70 | asm("mulu %2,%0 \n" /* MDR:val = val*mult */ | ||
| 71 | "divu %3,%0 \n" /* val = MDR:val/div; | ||
| 72 | * MDR = MDR:val%div */ | ||
| 73 | : "=r"(result) | ||
| 74 | : "0"(val), "ir"(mult), "r"(div) | ||
| 75 | ); | ||
| 76 | |||
| 77 | return result; | ||
| 78 | } | ||
| 79 | |||
| 80 | /* | ||
| 81 | * do a signed 32-bit multiply and divide with intermediate 64-bit product so | ||
| 82 | * as not to lose accuracy | ||
| 83 | * - we use the MDR register to hold the MSW of the product | ||
| 84 | */ | ||
| 85 | static inline __attribute__((const)) | ||
| 86 | signed __muldiv64s(signed val, signed mult, signed div) | ||
| 87 | { | ||
| 88 | signed result; | ||
| 89 | |||
| 90 | asm("mul %2,%0 \n" /* MDR:val = val*mult */ | ||
| 91 | "div %3,%0 \n" /* val = MDR:val/div; | ||
| 92 | * MDR = MDR:val%div */ | ||
| 93 | : "=r"(result) | ||
| 94 | : "0"(val), "ir"(mult), "r"(div) | ||
| 95 | ); | ||
| 96 | |||
| 97 | return result; | ||
| 98 | } | ||
| 99 | |||
| 100 | extern __attribute__((const)) | ||
| 101 | uint64_t div64_64(uint64_t dividend, uint64_t divisor); | ||
| 102 | |||
| 103 | #endif /* _ASM_DIV64 */ | ||
