On Thu, Nov 4, 2010 at 11:26 AM, Holger Freyther <[email protected]> wrote: > On 11/04/2010 10:52 AM, Eric Bénard wrote: >> this is a RFC, I think it can also be used on qt 4.6.x and on armv7. >> Setting QT_ARCH to armv6 enable some asm optimized functions in QT. > > Do you know the consequences of this change? E.g. in the painting > engine unaligned memory access will be allowed. I am not sure that Nokia has > ever benchmarked what is faster (aligned/unaligned) access. So it would be > very interesting to know the perf difference. E.g. use qttracereply to > measure it. > > Phil do you happen to know why unaligned access got allowed starting from > armv6? How fast will it be? >
The instructions can cope with unaligned data so the performance will not be impacted but its only upto 32-bit data above that the fault will still be generated and not all instructions can operate on unaligned data only ones operating on 32-bit data can do it. > _______________________________________________ > Openembedded-devel mailing list > [email protected] > http://lists.linuxtogo.org/cgi-bin/mailman/listinfo/openembedded-devel > _______________________________________________ Openembedded-devel mailing list [email protected] http://lists.linuxtogo.org/cgi-bin/mailman/listinfo/openembedded-devel
