On 05/20/2013 03:20 PM, David Edelsohn wrote:
This seems like a reasonable change and *should* improve performance, but what is the actual effect on performance, especially recent POWER processors? We have had some recent cases where increased alignment hurt performance because of secondary effects on spilling.
I've poked around a bit. We seem to have no suitable Altivec hardware for bare-metal benchmarking (we do simulator testing for -te600 instead), but we have a Freescale 8641D board available for GNU/Linux. It's about 5 years old so I don't know if it qualifies as a sufficiently recent processor? (Like I said before, we can't justify spending a lot of time trying to get this patch on mainline, and I especially don't want to waste time setting up benchmarking that would not be useful anyway.)
-Sandra
