RPI3, error: invalid operand in inline asm: 'rev16 ${0:w}, ${1:w}'

[bob prohaska]

On Sat, Mar 30, 2019 at 05:50:35PM +0000, John F Carr wrote:
> 
> 
> > On Mar 30, 2019, at 11:23 , bob prohaska <fbsd at www.zefox.net> wrote:
> > 
> > In a recent attempt to compile www/chromium on an RPI3 running r345516
> > compilation stopped with repeated reports of 
> > 
> > /usr/include/machine/endian.h:89:19: error: invalid operand in inline asm: 'rev16 ${0:w}, ${1:w}'
> > 
> > Chromium compiled on the same host a couple of months ago, but the 
> > executable failed on a runtime library error. Now attempts to upgrade
> > stop during compilation. Ports are presently at revision 496949.
> > 
> > Thanks for reading, and any guidance.
> > 
> > bob prohaska
> 
> The swap function at that line in sys/arm64/include/endian.h doesn't look right to me.  I think it should read
> 
>   __asm("rev16 %w0, %w1\n" : "=r" (ret) : "r" (w));
> 
> instead of
> 
>     __asm __volatile("rev16 %w0, %w1\n" : "=&r" (ret), "+r" (v));
> 
> Two changes: (1) it doesn't need to be volatile because it has no side effects and (2) the constraints and lack of explicit input operand are wrong.  The other swap functions should have similar changes.
> 

Apologies for being obtuse, but is that suggestive of a problem with the
host system, or a problem with the port?

Thanks for reading!

bob prohaska