I've managed to get some Pascal code to vectorize! See attached example. I used GNU Pascal version 20070904, based on gcc-4.3.6. (64bit) Earlier 4.3.x might work, please try it. Caveats; Array to vectorize must start with lower bound zero. Must use While loop (For loop did'nt work). 32 bit Integers not working, floats or 64bit Ints only. gpc -O3 -ftree-vectorizer-verbose=2 av.pas av.pas:19: note: LOOP VECTORIZED. av.pas:0: note: vectorized 1 loops in function. Regards, Peter