gmp z13 config fails with illegal instructions

[Matthias Klose]

seen with
https://launchpad.net/ubuntu/+source/gmp/2:6.3.0+dfsg-2ubuntu2/+build/26470068

Note, that MPN_PATH is now unset in 2:6.3.0+dfsg-2ubuntu3

[...]
../../../test-driver: line 112: 76812 Illegal instruction (core dumped) "$@" >> "$log_file" 2>&1
FAIL: t-hamdist
PASS: t-oddeven
../../../test-driver: line 112: 76824 Illegal instruction (core dumped) "$@" >> "$log_file" 2>&1
FAIL: t-popcount
PASS: t-set_f
PASS: t-io_raw
PASS: t-import
PASS: t-export
PASS: t-pprime_p
../../../test-driver: line 112: 76856 Illegal instruction (core dumped) "$@" >> "$log_file" 2>&1
FAIL: t-nextprime
PASS: t-remove
PASS: t-limbs
============================================================================
Testsuite summary for GNU MP 6.3.0
============================================================================
# TOTAL: 64
# PASS: 57
# SKIP: 0
# XFAIL: 0
# FAIL: 7
# XPASS: 0
# ERROR: 0
============================================================================
See tests/mpz/test-suite.log
Please report to <email address hidden> (see https://gmplib.org/manual/Reporting-Bugs.html)

[bugproxy (bugproxy)]

------- Comment From <email address hidden> 2023-08-03 10:39 EDT-------
I've reproduced those FAILs when running on z13 with gmp_6.3.0+dfsg-2ubuntu2.

Unfortunately not only the extended mnemonics for vpopct 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.

I've already send the obvious fix to the gmp-mailing-list:
'Revert "Move popcount and hamdist back from z14 to z13 after needed edits."'
https://gmplib.org/list-archives/gmp-devel/2023-August/006198.html
and Torbj?rn has already committed it:
https://gmplib.org/repo/gmp/rev/372acfd0c33e

With this patch applied, gmp_6.3.0+dfsg-2ubuntu2 builds without test-suite-fails on z13.

[Frank Heimes (fheimes)]

A test build of the patched package (now gmp_6.3.0+dfsg-2ubuntu4) is being build at PPA:
https://launchpad.net/~fheimes/+archive/ubuntu/lp2029438

The testsuite was successful - especially on s390x:

============================================================================
Testsuite summary for GNU MP 6.3.0
============================================================================
# TOTAL: 8
# PASS: 8
# SKIP: 0
# XFAIL: 0
# FAIL: 0
# XPASS: 0
# ERROR: 0
============================================================================

No lintian errors.

Attaching debdiff.

Subscribing 'ubuntu-sponsors'.

[bugproxy (bugproxy)]

------- Comment From <email address hidden> 2023-08-22 07:22 EDT-------
Hi Frank,
I've installed gmp_6.3.0+dfsg-2ubuntu4. The popcount/hamdist functions are not using vpopcnt z14-instructions anymore, which leaded to the segfault. And the z13 functions are now enabled again.
Thanks

[Frank Heimes (fheimes)]

Updated package has landed in mantic:
gmp | 2:6.3.0+dfsg-2ubuntu4 | mantic | source
Closing ticket as Fix Released.

[bugproxy (bugproxy)]

------- Comment From <email address hidden> 2023-08-28 04:22 EDT-------
Thanks @Canonical for catching this.
Thank you Stefan for your fix & successful verification.

The updated package has been included in Mantic, therefore we can close this bug.

==> Changing the status to: "CLOSED"