On 2015年09月19日 10:34, Richard Henderson wrote: > > There's a trick for this that's more efficient for 4 or more elements > per vector (i.e. good for v2 and v1, but not v4): > > a + b = (a & 0x7f7f7f7f) + (b & 0x7f7f7f7f)) ^ ((a ^ b) & 0x80808080) > > a - b = (a | 0x80808080) - (b & 0x7f7f7f7f)) ^ ((a ^ ~b) & 0x80808080) >
For me, we need use "(a ^ b) & 0x80..." instead of "(a ^ ~b) & 0x80...". Thanks. -- Chen Gang Open, share, and attitude like air, water, and life which God blessed