On 10/27/2011 06:05 AM, David Brown wrote: > > Where does it go wrong? Is it the automatic vectorisation with SSE, > etc., that is still too limited with gcc? I have done very little work > with x86/amd64 assembly (most of my experience is with microcontrollers > rather than "big" processors), so I haven't tried looking at gcc's SSE > code and comparing it to hand-optimised code. > The autovectorization isn't good enough to understand the tricks that are necessary to get good performance. They require leaning pretty hard on the instruction set. -hpa -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
