Re: What does this mean?

[Harold Grovesteen]

On Tue, 2023-05-30 at 10:08 +0200, Thomas Huth wrote:
> On 28/05/2023 14.23, Harold Grovesteen wrote:
> > It is triggered by a CLC instruction.  The "bizarre" cc goes away
> > when
> > the CLC instruction is commented out.
> > 
> > I can rework the code to avoid the use of the CLC instruction.  But
> > thought it should be shared.
> > 
> > /home/harold/qemu-7.2.0-rc4/install/bin/qemu-system-s390x -machine
> > s390-ccw-virtio -cpu max -m 3M -no-shutdown -nographic -serial
> > mon:stdio -kernel test12.elf
> > QEMU 7.1.94 monitor - type 'help' for more information
> > (qemu) info registers
> > 
> > CPU#0
> > PSW=mask 0000100180000000 addr 0000000000002034 cc CC_OP_LTUGTU_64
> 
> It's an internal representation of the condition code ... a little
> bit ugly 
> for the end user, I guess, but likely quite useful if you're working
> on the 
> instruction emulation within QEMU.
> 
> You can find more information here:
> 
>  
> https://gitlab.com/qemu-project/qemu/-/blob/v8.0.0/target/s390x/s390x-internal.h#L144
> 
>   HTH,
>    Thomas
> 
> 
Found that this cc also showed up with CLG.  Did some grep'ing.  And I
deduced it is related to how QEMU delays CC calculations until actually
needed.  So it looks to me to be a case where the CC calculation is
pending.

So as "likely quite useful if you're working on the instruction
emulation", is this indicative of a problem that requires attention or
is simply normal processing I can ignore?

That is the question I stumble up against frequently because I am going
"where few others have gone before" with QEMU.

Thomas, thanks for your help!  

Harold Grovesteen