| #ifndef _ASM_X86_DIV64_H |
| #define _ASM_X86_DIV64_H |
| |
| #ifdef CONFIG_X86_32 |
| |
| #include <linux/types.h> |
| |
| /* |
| * do_div() is NOT a C function. It wants to return |
| * two values (the quotient and the remainder), but |
| * since that doesn't work very well in C, what it |
| * does is: |
| * |
| * - modifies the 64-bit dividend _in_place_ |
| * - returns the 32-bit remainder |
| * |
| * This ends up being the most efficient "calling |
| * convention" on x86. |
| */ |
| #define do_div(n, base) \ |
| ({ \ |
| unsigned long __upper, __low, __high, __mod, __base; \ |
| __base = (base); \ |
| asm("":"=a" (__low), "=d" (__high) : "A" (n)); \ |
| __upper = __high; \ |
| if (__high) { \ |
| __upper = __high % (__base); \ |
| __high = __high / (__base); \ |
| } \ |
| asm("divl %2":"=a" (__low), "=d" (__mod) \ |
| : "rm" (__base), "0" (__low), "1" (__upper)); \ |
| asm("":"=A" (n) : "a" (__low), "d" (__high)); \ |
| __mod; \ |
| }) |
| |
| /* |
| * (long)X = ((long long)divs) / (long)div |
| * (long)rem = ((long long)divs) % (long)div |
| * |
| * Warning, this will do an exception if X overflows. |
| */ |
| #define div_long_long_rem(a, b, c) div_ll_X_l_rem(a, b, c) |
| |
| static inline long div_ll_X_l_rem(long long divs, long div, long *rem) |
| { |
| long dum2; |
| asm("divl %2":"=a"(dum2), "=d"(*rem) |
| : "rm"(div), "A"(divs)); |
| |
| return dum2; |
| |
| } |
| |
| static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder) |
| { |
| union { |
| u64 v64; |
| u32 v32[2]; |
| } d = { dividend }; |
| u32 upper; |
| |
| upper = d.v32[1]; |
| d.v32[1] = 0; |
| if (upper >= divisor) { |
| d.v32[1] = upper / divisor; |
| upper %= divisor; |
| } |
| asm ("divl %2" : "=a" (d.v32[0]), "=d" (*remainder) : |
| "rm" (divisor), "0" (d.v32[0]), "1" (upper)); |
| return d.v64; |
| } |
| #define div_u64_rem div_u64_rem |
| |
| extern uint64_t div64_64(uint64_t dividend, uint64_t divisor); |
| |
| #else |
| # include <asm-generic/div64.h> |
| #endif /* CONFIG_X86_32 */ |
| |
| #endif /* _ASM_X86_DIV64_H */ |