On Thu, Jul 16, 2015 at 03:14:30PM +0200, Jean-Claude Monnin wrote: > > Can you provide some additional detail on why this had to be disabled? > > The arm-v7a-linux-gnueabihf toolchain also has "cortex-strings" in > > PTXCONF_GLIBC_EXTRA_ADDONS and so far it seems to work fine (although > > I have only been able to do limited testing) > > With the "cortex-strings" enabled, it crashed somewhere in the boot process. > I assumed this option provided some optimised functions using NEON > instructions. However I never verified exactly what that option does. Maybe > someone else can clarify? > What hardware do you use? SAMA5D3 lacks NEON instructions, but SAMA5D4 does > support it. > 'cortex-strings' seems to be enabled in the 'arm-v7a-linux-gnueabihf' of > 'OSELAS toolchain 2013.12.2', but disabled in more recent versions of the > toolchain.
In the cortex-a8 toolchains we have 'cortex-strings'. These are string funtions that use NEON instructions unconditionally and are (in the version we use here) optimized for cortex-a8. A newer version of these functions reached mainline in gcc-4.9. There are optimized for cortex-a9. Also, NEON support is detected at runtime and approriate versions of the functions are selected. This is what we use in the arm-v7a-linux-gnueabihf toolchain since OSELAS.Toolchain-2014.12.0. Michael -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | -- ptxdist mailing list [email protected]
