[PATCH] Revert "Move popcount and hamdist back from z14 to z13 after needed edits."

[Stefan Liebler]

On 03.08.23 16:06, Torbjörn Granlund wrote:
> Stefan Liebler <stli at linux.ibm.com> writes:
> 
>   Unfortunately not only the extended mnemonics are not available with z13,
>   but also vpopct M3=1-3 is reserved. Thus you'll get an illegal-instruction
>   if run on z13 as vector enhancement facility 1 (introduced with z14) is
>   not available.
> 
> Ah, darn.  This will need to be fixed in a 6.3.1 when the dust settles.
Thanks for that. In the meantime, gmp 6.3.0 + this patch should be used.
Do you have plans for 6.3.1?
> 
> I only have a z15 to run tests on.  I don't have a reliable way of
> telling what instructions run on a particular implementation.  An
> instruction table with checkmarks per implementation would avoid this
> sort of problems.  IBM should be able provide that.
Indeed the best list I know is <binutils-src>/opcodes/s390-opc.txt. But
also see below. The POP also contains a small hint regarding the
M3-reserves, but I've overseen it.
> 
> A simple test I have used is to see what instructions the assembler
> accepts under various command-line options.  That depends on the GNU
> binutils developers to have made no mistake.
In this case, it does not cause an error as on z13 vpopct with M3 flag
is available. Unfortunately the assembler does not check the value of
M3-flag. Using vpopctg with --march=z13 will cause an error.
> 
> I also tried to make qemu help by passing -cpu XXX, as that has proven
> itself historically for other evolving ISAs.  The GMP test setup then
> can autotest things for several architectures, quickly triggering any
> incorrect instruction availability assumptions.  Unfortunately for
> qemu-s390x, all I get from passing say "-cpu z13" is an arm long
> non-parsable error message.  I have had no luck with any -cpu argument
> whatsoever.
> 
For me "qemu-system-s390x --cpu help" at least lists some z13 models,
but to be honest, I don't use it. I have to check.