[LAD] vectorization

Hello, I try to squeeze as much performance as possible out of my upcomming Linux synthesizer and try manual vectorization with following construct in c, mainly to vectorize away multiplications : typedef float v4sf __attribute__ ((vector_size(16))); union f4vector { v4sf v __attribute__((aligned (16))); float f[4] __attribute__((aligned (16))); }; On AMD 64bit Turion (single core) on 64 Studio in 64bit mode this doesnt improve performance at all, actually it even get worse. Is GCC that good at optimizing on its own? I have no access to Intel processors at the moment but would love to know how to benefit from SIMD optimizations of float operations. Sources on the web are rather thin... Cheers, Malte -- Malte Steiner media art + development -www.block4.com-