Converting addc to adcx

[Jeffrey Walton]

On Fri, May 31, 2019 at 7:47 AM Segher Boessenkool
<segher@kernel.crashing.org> wrote:
> ...
> > Man, it did not like that when using "&=r"(0ULL) (hundreds of them):
> >
> >      error: lvalue required in asm statement
> >
> > (I assume you wanted an early clobber on the input %3).
>
> You are saying there that you want to output to something that is constant 0.
> Yeah that doesn't work ;-)
>
> You should put the earlyclobber on the output, to tell GCC that that output
> (register) is clobbered early, i.e. before all inputs are used (so that GCC
> then knows to not put that output in the same place as one of the inputs).
> Like so:

Thanks Segher. That fixed it for me.

Jeff