rename div64_64 to div64_u64
[linux-3.10.git] / include / asm-x86 / div64.h
1 #ifndef _ASM_X86_DIV64_H
2 #define _ASM_X86_DIV64_H
3
4 #ifdef CONFIG_X86_32
5
6 #include <linux/types.h>
7
8 /*
9  * do_div() is NOT a C function. It wants to return
10  * two values (the quotient and the remainder), but
11  * since that doesn't work very well in C, what it
12  * does is:
13  *
14  * - modifies the 64-bit dividend _in_place_
15  * - returns the 32-bit remainder
16  *
17  * This ends up being the most efficient "calling
18  * convention" on x86.
19  */
20 #define do_div(n, base)                                         \
21 ({                                                              \
22         unsigned long __upper, __low, __high, __mod, __base;    \
23         __base = (base);                                        \
24         asm("":"=a" (__low), "=d" (__high) : "A" (n));          \
25         __upper = __high;                                       \
26         if (__high) {                                           \
27                 __upper = __high % (__base);                    \
28                 __high = __high / (__base);                     \
29         }                                                       \
30         asm("divl %2":"=a" (__low), "=d" (__mod)                \
31             : "rm" (__base), "0" (__low), "1" (__upper));       \
32         asm("":"=A" (n) : "a" (__low), "d" (__high));           \
33         __mod;                                                  \
34 })
35
36 /*
37  * (long)X = ((long long)divs) / (long)div
38  * (long)rem = ((long long)divs) % (long)div
39  *
40  * Warning, this will do an exception if X overflows.
41  */
42 #define div_long_long_rem(a, b, c) div_ll_X_l_rem(a, b, c)
43
44 static inline long div_ll_X_l_rem(long long divs, long div, long *rem)
45 {
46         long dum2;
47         asm("divl %2":"=a"(dum2), "=d"(*rem)
48             : "rm"(div), "A"(divs));
49
50         return dum2;
51
52 }
53
54 static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
55 {
56         union {
57                 u64 v64;
58                 u32 v32[2];
59         } d = { dividend };
60         u32 upper;
61
62         upper = d.v32[1];
63         d.v32[1] = 0;
64         if (upper >= divisor) {
65                 d.v32[1] = upper / divisor;
66                 upper %= divisor;
67         }
68         asm ("divl %2" : "=a" (d.v32[0]), "=d" (*remainder) :
69                 "rm" (divisor), "0" (d.v32[0]), "1" (upper));
70         return d.v64;
71 }
72 #define div_u64_rem     div_u64_rem
73
74 #else
75 # include <asm-generic/div64.h>
76 #endif /* CONFIG_X86_32 */
77
78 #endif /* _ASM_X86_DIV64_H */