On Wed, May 21, 2025 at 09:21:40AM GMT, Jakub Jelinek wrote:
>
> The existing testsuite never tests whether the padding bits are sign or zero
> extended or contain unknown values.
> In the s390x patch, info->extended is set to true, yet all bitint tests but
> bitint-64.c at -O3 pass.
>
> So, I'm really interested to know in which cases you found the existing code
> not doing the extensions, ideally simple {,un}signed _BitInt(N) with values
> X and Y doing arithmetic or logical operation OP.
> And put that into the new test(s), so that we can ensure that the extensions
> are performed correctly.
>
> Jakub
The current master branch does not seem to have _BitInt support for s390x,
is the patch on this list?
Also, I cannot find the relevant psABI definition or discussions at
https://github.com/IBM/s390x-abi
So I am not sure if the info->extended really affects parameter passing for
s390x,
or the exact definition of its psABI.
If you have a s390x targeted build with _BitInt enabled, you can perhaps try
gcc.target/aarch64/bitint-args.c on s390x to see if the parameters are actually
assumed to be extended by not emitting extraneous extension instruction(s),
which is one of the key reason to have them extended in psABI in the first
place.
