Re: Rational behind partial AVX support in Qemu

[Stevie Lavern]

Hello,

Thanks for you answer!

I may put together a patch to crash if VEX.L is 1 (shouldn't be hard) and submit it to the patch list.

Do you think it qualifies as "trivial patch" or should i go on with the full patch submission process? 

On Thu, Jan 6, 2022 at 3:45 AM Richard Henderson <richard.henderson@linaro.org> wrote:

On 1/5/22 9:09 AM, Stevie Lavern wrote:
> Hello,
> I'm currently testing various binaries under qemu linux user and went into a strange bug.
>
> Here is the TLDR: is there a reason to allow VEX.L to be 1 when not supporting AVX
> instructions?

There are some integer instructions that use vex encoding, e.g. andn, and we support some
of those, thus any support for VEX at all.  But you're probably correct that we could
usefully filter VEX.L = 1 early.


r~