GLIBC contains the following code in stdlib/longlong.h:
<snip>
#if defined (__mips__) && W_TYPE_SIZE == 32
#define umul_ppmm(w1, w0, u, v) \
__asm__ ("multu %2,%3" \
: "=l" ((USItype) (w0)), \
"=h" ((USItype) (w1)) \
: "d" ((USItype) (u)), \
"d" ((USItype) (v)))
#define UMUL_TIME 10
#define UDIV_TIME 100
#endif /* __mips__ */
</snip>
Actually, so does GCC itself. Can you prepare a patch?
What would be a correct fix in this case? Something like this:
<snip>
#define umul_ppmm(w1, w0, u, v) \
({unsigned int __attribute__((mode(DI))) __xx; \
__xx = (unsigned int __attribute__((mode(DI)))) u * v; \
w0 = __xx & ((1 << 32) - 1); \
w1 = __xx >> 32;})
</snip>
Or is there a better way?
Almost; this:
#define umul_ppmm(w1, w0, u, v) \
({UDWtype __xx; \
UWtype __u = (u), __v = (v); \
__xx = (UDWtype) __u * __v; \
w0 = (UWtype) __xx; \
w1 = __xx >> 32;})
should work.
Paolo
