The -ddextrastatevars setting allows to change the number of state variable pairs that are preallocated
before the actual model state variables. Previously, 20 state variable pairs were allocated for the
product construction (LTL). From now on, this is the default, but the amount can be changed, e.g., to
0 to force all automaton states to be allocated at the bottom of the MTBDD.
From now on, additionally, we also preallocate 20 action variables at the top of the MTBDD,
which will provide extra action / non-deterministic choice bits for symbolic model transformations
that require additional non-deterministic choices, e.g., additional special actions, etc.
The number of preallocated action variables is configurable by the -ddextraactionvars setting.
Adding the additional variables should not have a performance impact, as they are "don't cares"
in the normal MTBDD encoding of the models.
For the sparse and hybrid engine, allocating the nondeterministic choice variables at the top
makes sense for performance reasons (the submatrix for each choice is a sub-MTBDD), so we currently
only support extra action variables at the top.
git-svn-id: https://www.prismmodelchecker.org/svn/prism/prism/trunk@11944 bbc10eb1-c90d-0410-af57-cb519fbb1720
Joachim Klein
c94a4352a9