linux-stable-rt/arch/parisc/lib/libgcc/__umulsidi3.c

47 lines
1.1 KiB
C

#include "libgcc.h"
#define __ll_B ((u32) 1 << (32 / 2))
#define __ll_lowpart(t) ((u32) (t) & (__ll_B - 1))
#define __ll_highpart(t) ((u32) (t) >> 16)
#define umul_ppmm(w1, w0, u, v) \
do { \
u32 __x0, __x1, __x2, __x3; \
u16 __ul, __vl, __uh, __vh; \
\
__ul = __ll_lowpart (u); \
__uh = __ll_highpart (u); \
__vl = __ll_lowpart (v); \
__vh = __ll_highpart (v); \
\
__x0 = (u32) __ul * __vl; \
__x1 = (u32) __ul * __vh; \
__x2 = (u32) __uh * __vl; \
__x3 = (u32) __uh * __vh; \
\
__x1 += __ll_highpart (__x0);/* this can't give carry */ \
__x1 += __x2; /* but this indeed can */ \
if (__x1 < __x2) /* did we get it? */ \
__x3 += __ll_B; /* yes, add it in the proper pos. */ \
\
(w1) = __x3 + __ll_highpart (__x1); \
(w0) = __ll_lowpart (__x1) * __ll_B + __ll_lowpart (__x0); \
} while (0)
union DWunion {
struct {
s32 high;
s32 low;
} s;
s64 ll;
};
u64 __umulsidi3(u32 u, u32 v)
{
union DWunion __w;
umul_ppmm(__w.s.high, __w.s.low, u, v);
return __w.ll;
}