65  *	uv = (2^2n + 2^n) (u1 v1)  +			[u1v1 = high]
85  *	(2^n)(high) + (2^n)(mid) + (2^n + 1)(low)
89  *	(2^n)(high + mid + low) + low
91  * Furthermore, `high' and `mid' can be computed mod 2^n, as any factor
101 	u_long high, mid, udiff, vdiff;  in __muldi3()  local
133 		 * any upper bits in high and mid, so we can use native  in __muldi3()
148 		high = u1 * v1;  in __muldi3()
153 		prod.ul[H] = high + (negmid ? -mid : mid) + low.ul[L] +  in __muldi3()
179  * splits into high and low longs as HHALF(l) and LHUP(l) respectively.
184 	u_long u1, u0, v1, v0, udiff, vdiff, high, mid, low;  in __lmulq()  local
210 	high = u1 * v1;  in __lmulq()
212 	/* prod = (high << 2N) + (high << N); */  in __lmulq()
213 	prodh = high + HHALF(high);  in __lmulq()
214 	prodl = LHUP(high);  in __lmulq()