Contents of /alx-src/tags/kernel26-2.6.12-alx-r9/include/asm-arm/div64.h
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Wed Mar 4 11:03:09 2009 UTC (15 years, 3 months ago) by niro
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Wed Mar 4 11:03:09 2009 UTC (15 years, 3 months ago) by niro
File MIME type: text/plain
File size: 1151 byte(s)
Tag kernel26-2.6.12-alx-r9
1 | #ifndef __ASM_ARM_DIV64 |
2 | #define __ASM_ARM_DIV64 |
3 | |
4 | #include <asm/system.h> |
5 | |
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 | * In other words, a 64-bit dividend with a 32-bit divisor producing |
17 | * a 64-bit result and a 32-bit remainder. To accomplish this optimally |
18 | * we call a special __do_div64 helper with completely non standard |
19 | * calling convention for arguments and results (beware). |
20 | */ |
21 | |
22 | #ifdef __ARMEB__ |
23 | #define __xh "r0" |
24 | #define __xl "r1" |
25 | #else |
26 | #define __xl "r0" |
27 | #define __xh "r1" |
28 | #endif |
29 | |
30 | #define do_div(n,base) \ |
31 | ({ \ |
32 | register unsigned int __base asm("r4") = base; \ |
33 | register unsigned long long __n asm("r0") = n; \ |
34 | register unsigned long long __res asm("r2"); \ |
35 | register unsigned int __rem asm(__xh); \ |
36 | asm( __asmeq("%0", __xh) \ |
37 | __asmeq("%1", "r2") \ |
38 | __asmeq("%2", "r0") \ |
39 | __asmeq("%3", "r4") \ |
40 | "bl __do_div64" \ |
41 | : "=r" (__rem), "=r" (__res) \ |
42 | : "r" (__n), "r" (__base) \ |
43 | : "ip", "lr", "cc"); \ |
44 | n = __res; \ |
45 | __rem; \ |
46 | }) |
47 | |
48 | #endif |