search for: n3988

Hi, Consider this code: std::vector v; v.resize(256); for (i = 0; i < ... ; ++i) { a += v[b[i]]; } This is a gather loop, and should be able to be vectorized. *however*... I as a programmer can see that the size of v.data() is at least 256. I know because of the contract of std::vector that v.data() is a unique heap object that doesn't alias anything. However, LLVM knows none of this.