On Thu, Jan 25, 2018 at 3:13 PM, Peter Robinson <pbrobinson@xxxxxxxxx> wrote: > On Thu, Jan 25, 2018 at 3:02 PM, Florian Weimer <fweimer@xxxxxxxxxx> wrote: >> On 01/25/2018 03:52 PM, Peter Robinson wrote: >>> >>> On Thu, Jan 25, 2018 at 2:46 PM, Florian Weimer <fweimer@xxxxxxxxxx> >>> wrote: >>>> >>>> GCC offers a generic tuning option for Arm these days, but we select >>>> -mtune=cortex-8a instead. >>>> >>>> Is this still a good choice? >>> >>> >>> I suspect the generic tuning is likely a better choice, is there any >>> details about it anywhere? Basically Cortex-A8 is pretty much the >>> lowest common denominator for ARMv7 >> >> >> The generic tuning has this: > > So reading the gcc docs [1] it seems that generic-armv7-a makes sense. > > To quote "should tune the performance for a blend of processors within > architecture arch. The aim is to generate code that run well on the > current most popular processors, balancing between optimizations that > benefit some CPUs in the range, and avoiding performance pitfalls of > other CPUs." > > We still support a number of Cortex-A8 devices but we have a lot more > Cortex_A7/9/15 devices these days too so I think generic makes sense > here. I also wonder whether it's worthwhile using neon-vfpv3, I can't tell from the docs though if a SoC doesn't have neon if it will fall back to VFP3 or just fail altogether. Peter _______________________________________________ arm mailing list -- arm@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to arm-leave@xxxxxxxxxxxxxxxxxxxxxxx
