Re: [linus:master] BUILD REGRESSION a2e5790d841658485d642196dbb0927303d6c22f

From: Peter Zijlstra
Date: Thu Feb 08 2018 - 05:14:10 EST


On Thu, Feb 08, 2018 at 09:47:53AM +0000, David Laight wrote:
> From: Peter Zijlstra

> > I went through the register opcodes and matched it against the ModR/M
> > encoding, and the best option I've found so far is using 0xd6 as the
> > next byte.
>
> Wouldn't 0xc3 work as well.
> A retq is probably better than an extra (bad).

I explicity did not use c3 because that generates spurious "retq" in the
code flow which is mighty confusing when you read the stuff.