tree a5f9430452c65388466ffa855bfc3e178b53e66c
parent 2aa3f1651237397c2d9f120d20921b9d2cd73d32
author Gilles Peskine <Gilles.Peskine@arm.com> 1623786272 +0200
committer Gilles Peskine <Gilles.Peskine@arm.com> 1624358841 +0200

Fix multiplication with negative result and a low-order 0 limb

Fix a bug introduced in "Fix multiplication producing a negative zero" that
caused the sign to be forced to +1 when A > 0, B < 0 and B's low-order limb
is 0.

Add a non-regression test. More generally, systematically test combinations
of leading zeros, trailing zeros and signs.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>