[PATCH v2 0/7] Optimize jump label implementation on ARM64

[Jiang Liu]

On 10/14/2013 11:40 PM, Russell King - ARM Linux wrote:
> On Sun, Oct 13, 2013 at 10:50:20PM +0800, Jiang Liu wrote:
>> To enable this feature, your toolchain must support "asm goto" extension
>> and "%c" constraint extesion. Current GCC for AARCH64 doesn't support
>> "%c", so you need a GCC patch similiar to this:
> 
> Oh god, not that again.  I've no idea why ARM stuff has such a problem with
> supporting this very useful "%c" GCC constraint.  Aarch32 didn't for ages
> consequently we now have horrid hacks around it in the kernel source
> because our compilers suck.  Seems Aarch64 is doomed to repeat the same
> stupid mistakes. :(
> 
We need to do the same trick for ARM64 too:)