This PR makes sure that the expression level cache in bv_decide is
maintained across the entire bitblaster instead of just locally per
BitVec expression.
The PR was split off from the first one (#7606) as this mostly entails
pulling the invariant through and is thus much more mechanical.
This PR adds the known bits optimization from the multiplication circuit
to the add one, allowing us to discover potentially even more symmetries
before going to the SAT solver.
This PR adds short-circuit support to bv_decide to accelerate
multiplications with shared coefficients. In particular, `a * x = b * x`
can be extended to `a = b v (a * x = b * x)`. The latter is faster if `a
= b` is true, as `a = b` may be evaluated without considering the
multiplication circuit. On the other hand, we require the multiplication
circuit, as `a * x = b * x -> a = b` is not always true due to two's
complement wrapping.
We support multiplications through acNF, which takes into account shared
terms across equality canonicalizing `a * (b * c1) = a * (b * c2)` to
`(a * b) * c1 = (a * b) * c2`. As a result, the non-shared terms are
lifted to the top such that canonical rewrites for binary multiplication
with shared terms on the left/right are sufficient.
We add an option `bv_decide +shortCircuit` which controls this feature
(currently disabled by default).
---------
Co-authored-by: Siddharth Bhat <siddu.druid@gmail.com>
Co-authored-by: Henrik Böving <hargonix@gmail.com>
This PR adds SMT-LIB operators to detect overflow `BitVec.negOverflow`,
according to the [SMTLIB
standard](https://github.com/SMT-LIB/SMT-LIB-2/blob/2.7/Theories/FixedSizeBitVectors.smt2),
and the theorem proving equivalence of such definition with the `BitVec`
library functions (`negOverflow_eq`).
Co-authored by @bollu and @alexkeizer
---------
Co-authored-by: Siddharth <siddu.druid@gmail.com>
This PR provides lemmas about the tree map function `minKey?` and its
interaction with other functions for which lemmas already exist.
---------
Co-authored-by: Paul Reichert <datokrat@users.noreply.github.com>
This PR introduces TCP socket support using the LibUV library, enabling
asynchronous I/O operations with it.
---------
Co-authored-by: Henrik Böving <hargonix@gmail.com>
Co-authored-by: Markus Himmel <markus@himmel-villmar.de>
This PR refactors the AIG datastructures that underly bv_decide in order
to allow a better tracking of negations in the circuit. This refactor
has two effects, for one adding full constant folding to the AIG
framework and secondly enabling us to add further simplifications from
the Brummayer Biere paper in the future which was previously
architecturally impossible.
This PR adds the BV_EXTRACT_CONCAT_LHS_RHS, NORM_BV_ADD_MUL and
NORM_BV_SHL_NEG rewrite from Bitwuzla as well as a reduction from
getLsbD to extractLsb' to bv_decide.
This PR adds the equivalent of `Array.emptyWithCapacity` to the AIG
framework and applies it to `bv_decide`. This is particularly useful as
we are only working with capacities that are always known at run time so
we should never have to reallocate a `RefVec`.
There are several things done here:
1. Use the modified `simp_to_model` which already exists in hash maps.
This version of `simp_to_model` allows specifying the query operations
to use in addition to the modifying operations. This is mostly to
improve elaboration time and actually increases olean size.
2. Instead of proving `toListModel_balance` directly, we write
`toListModel_balanceₘ` and use that instead (this saves ~3 MB).
3. Use `fun_cases` and `dsimp` instead of `rw [x.eq_def]` more
frequently in `Balancing.olean` (this saves a bit over 2 MB).
4. Mark `updateCell` and other functions dependent on it as
`noncomputable`. The main problem with `updateCell` is how other
functions, in particular `glue`, get recursively inlined, which blows
the size of the IR (this saves ~1 MB).
5. Instead of using `simp_to_model` to prove results on `insert!`,
`erase!`, etc., `simpa`s are used now, e.g. `simpa only
[insert_eq_insert!] using isEmpty_insert h`. This mainly improves
elaboration time although the olean size also goes down by ~0.3 MB.
This PR achieves a speed up in bv_decide's LRAT checker by improving its
input validation.
When the LRAT checker works on a clause it needs to know that the clause
has no duplicate literals and is not tautological (i.e. doesn't contain
the same variable in different polarities). Previously this was done
using a naive quadratic algorithm, now we check the property using a
HashMap in linear time. Beyond this there is also a few micro
optimizations.
Together they improve the runtime on the SMTLIB problem
`non-incremental/QF_BV/20210312-Bouvier/vlsat3_a15.smt2` from `1:25.31`
to `1:01.32` minutes (where 39 seconds of this run time are the SAT
solver and thus completely unaffected by the optimization)
Co-authored-by: @JOSHCLUNE
---------
Co-authored-by: JOSHCLUNE <josh.seth.clune@gmail.com>
With `USE_LAKE=ON`, only linking is now left to the Makefile.
TODO:
* include stage 0 changes in Lake's trace. This is an issue already on
master but prevents us from using this PR to put .oleans in an Actions
cache.
This PR makes the style of all `List` docstrings that appear in the
language reference consistent.
Relies on #7240 for links and example formatting.
---------
Co-authored-by: Kim Morrison <kim@tqft.net>
This PR provides lemmas about the tree map that have been introduced to
the hash map in #7289.
---------
Co-authored-by: Paul Reichert <6992158+datokrat@users.noreply.github.com>
This PR renames the member `insert_emptyc_eq` of the `LawfulSingleton`
typeclass to `insert_empty_eq` to conform to the recommended spelling of
`∅` as `empty`.
See also #7447.
This PR prefers using `∅` instead of `.empty` functions. We may later
rename `.empty` functions to avoid the naming clash with
`EmptyCollection`, and to better express semantics of functions which
take an optional capacity argument.
This PR provides lemmas about the tree map function `modify` and its
interactions with other functions for which lemmas already exist.
---------
Co-authored-by: Paul Reichert <6992158+datokrat@users.noreply.github.com>
This PR renames several hash map lemmas (`get` -> `getElem`) and uses
`m[k]?` instead of `get? m k` (and also for `get!` and `get`).
BREAKING CHANGE: While many lemmas were renamed and the lemma with the
old signature was simply deprecated, some lemmas were changed without
renaming them. They now use the `getElem` variants instead of `get`.
---------
Co-authored-by: Paul Reichert <6992158+datokrat@users.noreply.github.com>
This PR moves `DHashMap.Raw.foldRev(M)` into `DHashMap.Raw.Internal`.
---------
Co-authored-by: Paul Reichert <6992158+datokrat@users.noreply.github.com>
This PR provides lemmas for the tree map functions `alter` and `modify`
and their interactions with other functions for which lemmas already
exist.
BREAKING CHANGE: The signature of `size_alter` was corrected for all
four hash map types. Instead of relying on the boolean operations
`contains` and `&&` in the if statements, we now use the `Prop`-based
operations `Membership` and `And`.
---------
Co-authored-by: Paul Reichert <6992158+datokrat@users.noreply.github.com>
This PR adds rules for `-1#w * a = -a` and `a * -1#w = -a` to
bv_normalize as seen in Bitwuzla's BV_MUL_SPECIAL_CONST.
This allows us to solve
```lean
example {a : BitVec 32} : a + -1 * a = 0 := by bv_normalize
```
which would previously time out.
This PR makes bv_decide's preprocessing handle casts, as we are in the
constant BitVec fragment we should be able to always remove them using
BitVec.cast_eq.
This PR provides lemmas about the tree map function `ofList` and
interactions with other functions for which lemmas already exist.
---------
Co-authored-by: Paul Reichert <6992158+datokrat@users.noreply.github.com>
This PR provides lemmas about the tree map function `insertMany` and its
interaction with other functions for which lemmas already exist. Most
lemmas about `ofList`, which is related to `insertMany`, are not
included.
---------
Co-authored-by: Paul Reichert <6992158+datokrat@users.noreply.github.com>
This PR upgrades the CaDiCal we ship and use for bv_decide to version
2.1.2. Additionally it enables binary LRAT proofs on windows by default
as https://github.com/arminbiere/cadical/issues/112 has been fixed.
Version 2.1.3 is already available but as the Bitwuzla authors [have
pointed out](https://github.com/bitwuzla/bitwuzla/pull/129) one needs to
be careful when upgrading CaDiCal so we just move to a version [they
confirmed](6e93389d86)
is fine for now.
This PR provides lemmas about the tree map functions `foldlM`, `foldl`,
`foldrM` and `foldr` and their interactions with other functions for
which lemmas already exist. Additionally, it generalizes the
`fold*`/`keys` lemmas to arbitrary tree maps, which were previously
stated only for the `DTreeMap α Unit` case.
A later PR will make the hash map functions `fold` and `revFold`
internal and also update their signature to conform to the tree map and
list API. This is out of scope for this PR.
---------
Co-authored-by: Paul Reichert <6992158+datokrat@users.noreply.github.com>
