Re: [RFC PATCH] tests/tcg: drop -cpu max from s390x sha512-mvx invocation

[Thomas Huth]

On 10/03/2022 12.35, Richard Henderson wrote:
> On 3/10/22 02:21, Thomas Huth wrote:
> > On 10/03/2022 09.36, Thomas Huth wrote:
[...]
> > > However, the error still persists. I now had a closer look by running the 
> > > test with "qemu-s390x" on my z15 machine directly, and all tests are 
> > > failing! The problem happens with both, gcc v11.2.1 and clang v13.0.1. 
> > > The problem goes away (i.e. test works fine) if I compile the code with 
> > > -O1 instead of -O3, or if I use GCC v8.5 instead. I'll try to find out 
> > > more, but as a temporary workaround, we could also switch to -O1 instead 
> > > of -O3.
> >
> > I noticed that the problem does not occur when running the test natively
> > on my s390x box, or via qemu-s390x on my x86 laptop, or when running it
> > via qemu-s390x v6.1.0 on my s390x box. So it's something wrong in the TCG
> > backend, I think, and I was able to bisect the issue down to this commit
> > here:
> >
> > $ git bisect bad
> > 9bca986df88b8ea46b100e3d21cc9e653c83e0b3 is the first bad commit
> > commit 9bca986df88b8ea46b100e3d21cc9e653c83e0b3
> > Author: Richard Henderson <richard.henderson@linaro.org>
> > Date:   Mon Sep 14 20:36:36 2020 -0700
> >
> >      tcg/s390x: Implement TCG_TARGET_HAS_bitsel_vec
> >
> > Richard, could you please have a look? 
[...]> Ok, will look soon.
> Would you pop this into an issue so I don't forget, please?

Sure, I've created a ticket here:

 https://gitlab.com/qemu-project/qemu/-/issues/898

 Thomas