* src/misc/intvcmp2.cc, src/misc/intvcmp2.hh: New files.
* src/misc/Makefile.am: Add them.
* src/tgbatest/intvcmp2.cc: New test.
* src/tgbatest/Makefile.am: Add it.
* src/tgbatest/intvcomp.test: Call it.

This avoids a library call to bdd_addref or bdd_delref.

* src/kernel.c (bdd_delref_nc, bdd_addref_nc): New function,
that work only on BDD that are not constant.
* src/cpext.cxx (bdd::operator=): Move...
* src/bdd.hh (bdd::operator=): ... here.
(bdd::bdd, bdd::~bdd, bdd::operator=): Inline the "is bdd constant"
check and call bdd_delref_nc/bdd_addref_nc only otherwise.

* src/bdd.h (__likely, __unlikely): Introduce these two macros.
* src/bddop.c, src/kerner.c: Use them in many situations.

* src/misc/intvcomp.cc (stream_compression_base::run): Limit
repeatitions to 40, not 42.
(stream_decompression_base::refill): Refill the end of the stream
with 0.
(stream_decompression_base::look_n_bits): Add assertion.
* src/tgbatest/intvcomp.cc: Add a new test case.

* src/misc/intvcomp.cc, src/misc/intvcomp.cc: Add interfaces to
compress vector<int> to vector<unsigned>.
* src/tgbatest/intvcomp.cc: Test them.
* src/sanity/style.test: Refine check to avoid a spurious report.

* configure.ac: Do not add CXXFLAGS and CFLAGS in ac_configure_args,
it causes problem when using config.cache.  Instead ...
* m4/devel.m4: Add --enable-devel or --disable-devel on
ac_configure_args, now that BuDDy understands that.

Fix some warnings reported by gcc.

* buddy/src/kernel.c (errorstrings): Mark these as const.
* buddy/src/reorder.c (reorder_gbc): Fix prototype.
(siftTestCmp): Add missing const in cast.
(bdd_reorder_auto): Actually call bdd_reorder_ready().

Add support for --enable-devel and similar macros.

* m4/debug.m4: Rename to ...
* m4/bdebug.m4: ... this.
* m4/debug.m4, m4/devel.m4, m4/gccoptim.m4, m4/ndebug.m4: New file.
* m4/gccwarns.m4: Fix usage of cache variable.  Fix shell
syntax.  Do not check for -Waggregate-return.  Update CFLAGS.
* configure.ac: Adjust to handle --enable-devel and similar macros
in the same way as Spot.

* src/misc/intvcomp.hh: Likewise.

* src/misc/intvcomp.hh: Move all code...
* src/misc/intvcomp.cc: ... in this new file.
* src/misc/Makefile.am: Add invcomp.cc

* iface/dve2/dve2.cc: Adjust to use the new mspool allocator,
and get rid of the std::vector used to store compressed states.
* src/misc/intvcomp.hh: Add an "int* -> int*" interface
in addition to the "int* -> vector<unsigned>*" interface.
* src/tgbatest/intvcomp.cc: Test the two interfaces.

* src/misc/mspool.hh: New file.
* src/misc/Makefile.am: Add it.

* iface/dve2/dve2.cc (dve2_compressed_state): New class.
(callback_context): Deal with general state*s, not dve2_state*s.
(transition_callback_compress): New function.
(dve2_kripke): Take a compress option.
(get_init_state, compute_state_condition, succ_iter,
format_state, state_condition): Handle compressed states.
(get_vars, compute_state_condition_aux): New helper methods.
* iface/dve2/dve2.hh (load_dve2): Add a compress option.
* iface/dve2/dve2check.cc: Add a -z option.
* iface/dve2/finite.test, iface/dve2/dve2check.test: Add more
tests.

* src/misc/intvcomp.hh: New file.
* src/misc/Makefile.am: Add it.
* src/tgbatest/intvcomp.cc, src/tgbatest/intvcomp.test: New files.
* src/tgbatest/Makefile.am: Add them.

* wrap/python/tests/setxor.py, wrap/python/tests/bddnqueen.py:
Clean all used bdd variables before calling bdd_done(), so that
bdd_delref() is never called after bdd_done().  In NDEBUG builds,
bdd_delref() does not check whether the BuDDy is running or not,
and calling it after bdd_done() will crash.

during emptiness check or counterexample generation.

Tag functions with attributes pure, const, or noreturn.

* src/bdd.h (__purefn, __constfn, __noreturnfn): Define
new macros.
* src/bdd.h, src/bddio.c, src/bvec.h, src/imatrix.h: Use them
to tag many functions as suggested by -Wsuggest-attribute=pure,
-Wsuggest-attribute=const, -Wsuggest-attribute=noreturn.

Remove more sanity checks when NDEBUG is set.

* src/kernel.h (CHECKnc): New macro.
* src/kernel.c (bdd_var, bdd_low, bdd_high, bdd_ithvar,
bdd_nithvar): Use it.

a fixed-size memory pool for product_state instances.

instances and their variables.

* src/misc/fixpool.hh: New file.
* src/misc/Makefile.am (misc_HEADERS): Add fixpool.hh.

* src/kernel.h (CHECK, CHECKa, CHECKn): Disable if NDEBUG is set.

Fix declaration of bddproduced.

* src/reorder.c (bddproduced): Declare a longint, to match
the definition in kerner.c.

settings to sub configure.

* buddy/src/kernel.c (bdd_addref, bdd_delref): Disable sanity
checks when compiled with NDEBUG.

* src/misc/casts.hh: New file.
* src/misc/Makefile.am: Add it.
* iface/dve2/dve2.cc, iface/gspn/gspn.cc, iface/gspn/ssp.cc,
src/evtgba/explicit.cc, src/evtgba/product.cc, src/misc/casts.hh,
src/tgba/state.hh, src/tgba/statebdd.cc, src/tgba/taatgba.cc,
src/tgba/taatgba.hh, src/tgba/tgbabddconcrete.cc,
src/tgba/tgbaexplicit.cc, src/tgba/tgbaexplicit.hh,
src/tgba/tgbakvcomplement.cc, src/tgba/tgbaproduct.cc,
src/tgba/tgbasafracomplement.cc, src/tgba/tgbasgba.cc,
src/tgba/tgbatba.cc, src/tgba/tgbaunion.cc, src/tgba/wdbacomp.cc,
src/tgbaalgos/ndfs_result.hxx, src/tgbaalgos/reductgba_sim.cc,
src/tgbaalgos/reductgba_sim_del.cc: Use down_cast when
appropriate.

* src/sanity/style.test: Catch some binary operators not
delimited with spaces.
* src/tgbaalgos/bfssteps.cc, src/tgbaalgos/magic.cc,
src/tgbaalgos/reducerun.cc, src/tgbaalgos/se05.cc,
src/tgbaalgos/tau03.cc, src/tgbaalgos/tau03opt.cc: Fix these.

* src/tgba/tgbaexplicit.cc, src/tgba/tgbaexplicit.hh: Merge
state_explicit and tgba_explicit::state.  In the past,
state_explicit was a small object encapsulating a pointer to the
persistent tgba_explicit::state; and we used to clone() and
destroy() a lot of state_explicit instance.  Now state_explicit is
persistent, and clone() and destroy() have no effects.
* src/tgba/tgbareduce.cc: Adjust, since this inherits from
tgbaexplicit and uses the internals of state_explicit.
* src/tgbatest/reductgba.cc: Fix deletion order for automata.
* src/tgba/tgba.hh (last_support_conditions_input_,
last_support_variables_input_): Make these protected, so
they can be zeroed by tgba_explicit.

* src/tgba/tgbareduc.cc, src/tgba/tgbareduc.hh (format_state):
Remove this useless copy of the tgba_explicit_string::format_state
method.

Client code should always call the destroy() method instead.  (It
was introduced in Spot 0.7.)

* src/tgba/state.hh (state::~state): Make it protected.

The gain is not very impressive.  The runtime of the first example
in iface/dve2/README (also in dve2check.test) is 15% faster.

* src/tgba/tgbaproduct.hh (tgba_succ_iterator_product): Move ...
* src/tgba/tgbaproduct.cc (tgba_succ_iterator_product,
tgba_succ_iterator_product_common): ... in these two classes.
(tgba_succ_iterator_product_kripke): New class to speedup
successor computation on Kripke structures.  We can assume that
all the transitions leaving the same state have the same label.
(tgba_product::tgba_product, tgba_product::succ_iter): Use
tgba_succ_iterator_product_kripke when appropriate.
(tgba_product_init::tgba_product_init): Adjust for the case
where tgba_product did reverse its operands.