1 #include <xen/lib.h>
2 
3 /* Compute with 96 bit intermediate result: (a*b)/c */
muldiv64(uint64_t a,uint32_t b,uint32_t c)4 uint64_t muldiv64(uint64_t a, uint32_t b, uint32_t c)
5 {
6 #ifdef CONFIG_X86
7     asm ( "mulq %1; divq %2" : "+a" (a)
8                              : "rm" ((uint64_t)b), "rm" ((uint64_t)c)
9                              : "rdx" );
10 
11     return a;
12 #else
13     union {
14         uint64_t ll;
15         struct {
16 #ifdef WORDS_BIGENDIAN
17             uint32_t high, low;
18 #else
19             uint32_t low, high;
20 #endif
21         } l;
22     } u, res;
23     uint64_t rl, rh;
24 
25     u.ll = a;
26     rl = (uint64_t)u.l.low * (uint64_t)b;
27     rh = (uint64_t)u.l.high * (uint64_t)b;
28     rh += (rl >> 32);
29     res.l.high = rh / c;
30     res.l.low = (((rh % c) << 32) + (uint32_t)rl) / c;
31 
32     return res.ll;
33 #endif
34 }
35 
36 /*
37  * Local variables:
38  * mode: C
39  * c-file-style: "BSD"
40  * c-basic-offset: 4
41  * tab-width: 4
42  * indent-tabs-mode: nil
43  * End:
44  */
45