feat(BV, CP): Propagators for addition and multiplication #1083

bclement-ocp · 2024-03-29T17:32:02Z

This patch adds constraints to represent bit-vector addition and
multiplication, with propagators in the interval domain and a simple
propagator for multiplication that only considers the factors-of-two
multiples in the bit-vector domain (this information cannot be captured
by the interval domain due to imprecise handling of overflow).

No propagator for addition in the bit-vector domain is provided yet,
although the plan is to add a full-adder propagator to provide a limited
form of local bit-blasting, as suggested in

S. Bardin, P. Herrmann, and F. Perroud.
“An Alternative to SAT-Based Approaches for Bit-Vectors”.
In: TACAS. 2010.

Note: this requires and currently includes #1058 ; the commit titled "feat(BV, CP): Propagators for addition and multiplication" is new.

bclement-ocp · 2024-05-07T10:25:51Z

Rebased with the new Intervals module from #1108

Halbaroth · 2024-06-21T08:04:25Z

Can you rebase this PR please? I will review it today :)

This patch adds constraints to represent bit-vector addition and multiplication, with propagators in the interval domain and a simple propagator for multiplication that only considers the factors-of-two multiples in the bit-vector domain (this information cannot be captured by the interval domain due to imprecise handling of overflow). No propagator for addition in the bit-vector domain is provided yet, although the plan is to add a full-adder propagator to provide a limited form of *local* bit-blasting, as suggested in S. Bardin, P. Herrmann, and F. Perroud. “An Alternative to SAT-Based Approaches for Bit-Vectors”. In: TACAS. 2010.

bclement-ocp · 2024-06-21T08:47:59Z

I don't understand why GitHub was saying there were merge conflicts in a bunch of files there were none? I force pushed again and that seems to have solved it.

Halbaroth

Just few questions but looks already pretty good for me.

src/lib/reasoners/bitlist.mli

src/lib/reasoners/bitlist.ml

src/lib/reasoners/bitv_rel.ml

bclement-ocp

Thanks for the review — ready for round 2

src/lib/reasoners/bitlist.ml

src/lib/reasoners/bitv_rel.ml

src/lib/reasoners/bitlist.ml

src/lib/reasoners/bitlist.mli

…1083) This patch adds constraints to represent bit-vector addition and multiplication, with propagators in the interval domain and a simple propagator for multiplication that only considers the factors-of-two multiples in the bit-vector domain (this information cannot be captured by the interval domain due to imprecise handling of overflow). No propagator for addition in the bit-vector domain is provided yet, although the plan is to add a full-adder propagator to provide a limited form of *local* bit-blasting, as suggested in S. Bardin, P. Herrmann, and F. Perroud. “An Alternative to SAT-Based Approaches for Bit-Vectors”. In: TACAS. 2010.

CHANGES: ### Command-line interface - Enable FPA theory by default (OCamlPro/alt-ergo#1177) - Remove deprecated output channels (OCamlPro/alt-ergo#782) - Deprecate the --use-underscore since it produces models that are not SMT-LIB compliant (OCamlPro/alt-ergo#805) - Add --dump-models-on to dump models on a specific output channel (OCamlPro/alt-ergo#838) - Use consistent return codes (OCamlPro/alt-ergo#842) - Add --continue-on-error flag to set the SMT-LIB error behavior (OCamlPro/alt-ergo#853) - Make dolmen the default value for the --frontend option (OCamlPro/alt-ergo#857) - Restore functionality to broken `--profiling` option (OCamlPro/alt-ergo#947) - Add bare-bones support for interactive input in SMT-LIB format (OCamlPro/alt-ergo#949) - Less confusing behavior on timeout (OCamlPro/alt-ergo#982, OCamlPro/alt-ergo#984) - Add `--strict` option for SMT-LIB compliant mode (OCamlPro/alt-ergo#916, OCamlPro/alt-ergo#1133) - Deprecate `sum`, `typing` and `warnings` debug flags (OCamlPro/alt-ergo#1204) ### SMT-LIB support - Add support for the many new SMT-LIB commands (OCamlPro/alt-ergo#837, OCamlPro/alt-ergo#848, OCamlPro/alt-ergo#852, OCamlPro/alt-ergo#863, OCamlPro/alt-ergo#911, OCamlPro/alt-ergo#942, OCamlPro/alt-ergo#945, OCamlPro/alt-ergo#961, OCamlPro/alt-ergo#975, OCamlPro/alt-ergo#1069) - Expose the FPA rounding builtin in the SMT-LIB format (OCamlPro/alt-ergo#876, OCamlPro/alt-ergo#1135) - Allow changing the SAT solver using (set-option) (OCamlPro/alt-ergo#880) - Add support for the `:named` attribute (OCamlPro/alt-ergo#957) - Add support for quoted identifiers (OCamlPro/alt-ergo#909, OCamlPro/alt-ergo#972) - Add support for naming lemmas in SMT-LIB syntax (OCamlPro/alt-ergo#1141, OCamlPro/alt-ergo#1143) ### Model generation - Use post-solve SAT environment in model generation, fixing issues where incorrect models were generated (OCamlPro/alt-ergo#789) - Restore support for records in models (OCamlPro/alt-ergo#793) - Use abstract values instead of dummy values in models where the actual value does not matter (OCamlPro/alt-ergo#804, OCamlPro/alt-ergo#835) - Use fresh names for all abstract values to prevent accidental captures (OCamlPro/alt-ergo#811) - Add support for model generation with the default CDCL solver (OCamlPro/alt-ergo#829) - Support model generation for the BV theory (OCamlPro/alt-ergo#841, OCamlPro/alt-ergo#968) - Add support for optimization (MaxSMT / OptiSMT) with lexicographic Int and Real objectives (OCamlPro/alt-ergo#861, OCamlPro/alt-ergo#921) - Add a SMT-LIB printer for expressions (OCamlPro/alt-ergo#952, OCamlPro/alt-ergo#981, OCamlPro/alt-ergo#1082, OCamlPro/alt-ergo#931, OCamlPro/alt-ergo#932) - Ensure models have a value for all constants in the problem (OCamlPro/alt-ergo#1019) - Fix a rare soundness issue with integer constraints when model generation is enabled (OCamlPro/alt-ergo#1025) - Support model generation for the ADT theory (OCamlPro/alt-ergo#1093, OCamlPro/alt-ergo#1153) ### Theory reasoning - Add word-level propagators for the BV theory (OCamlPro/alt-ergo#944, OCamlPro/alt-ergo#1004, OCamlPro/alt-ergo#1007, OCamlPro/alt-ergo#1010, OCamlPro/alt-ergo#1011, OCamlPro/alt-ergo#1012, OCamlPro/alt-ergo#1040, OCamlPro/alt-ergo#1044, OCamlPro/alt-ergo#1054, OCamlPro/alt-ergo#1055, OCamlPro/alt-ergo#1056, OCamlPro/alt-ergo#1057, OCamlPro/alt-ergo#1065, OCamlPro/alt-ergo#1073, OCamlPro/alt-ergo#1144, OCamlPro/alt-ergo#1152) - Add interval domains and arithmetic propagators for the BV theory (OCamlPro/alt-ergo#1058, OCamlPro/alt-ergo#1083, OCamlPro/alt-ergo#1084, OCamlPro/alt-ergo#1085) - Native support for bv2nat of bit-vector normal forms (OCamlPro/alt-ergo#1154) - Fix incompleteness issues in the BV solver (OCamlPro/alt-ergo#978, OCamlPro/alt-ergo#979) - Abstract more arguments of AC symbols to avoid infinite loops when they contain other AC symbols (OCamlPro/alt-ergo#990) - Do not make irrelevant decisions in CDCL solver, improving performance slightly (OCamlPro/alt-ergo#1041) - Rewrite the ADT theory to use domains and integrate the enum theory into the ADT theory (OCamlPro/alt-ergo#1078, OCamlPro/alt-ergo#1086, OCamlPro/alt-ergo#1087, OCamlPro/alt-ergo#1091, OCamlPro/alt-ergo#1094, OCamlPro/alt-ergo#1138) - Rewrite the Intervals module entirely (OCamlPro/alt-ergo#1108) - Add maximize/minimize terms for matching (OCamlPro/alt-ergo#1166) - Internalize `sign_extend` and `repeat` (OCamlPro/alt-ergo#1192) - Run cross-propagators to completion (OCamlPro/alt-ergo#1221) - Support binary distinct on arbitrary bit-widths (OCamlPro/alt-ergo#1222) - Only perform optimization when building a model (OCamlPro/alt-ergo#1224) - Make sure domains do not overflow the default domain (OCamlPro/alt-ergo#1225) - Do not build unnormalized values in `zero_extend` (OCamlPro/alt-ergo#1226) ### Internal/library changes - Rewrite the Vec module (OCamlPro/alt-ergo#607) - Move printer definitions closer to type definitions (OCamlPro/alt-ergo#808) - Mark proxy names as reserved (OCamlPro/alt-ergo#836) - Use a Zarith-based representation for numbers and bit-vectors (OCamlPro/alt-ergo#850, OCamlPro/alt-ergo#943) - Add native support for (bvnot) in the BV solver (OCamlPro/alt-ergo#856) - Add constant propagators for partially interpreted functions (OCamlPro/alt-ergo#869) - Remove `Util.failwith` in favor of `Fmt.failwith` (OCamlPro/alt-ergo#872) - Add more `Expr` smart constructors (OCamlPro/alt-ergo#877, OCamlPro/alt-ergo#878) - Do not use existential variables for integer division (OCamlPro/alt-ergo#881) - Preserve `Subst` literals to prevent accidental incompleteness (OCamlPro/alt-ergo#886) - Properly start timers (OCamlPro/alt-ergo#924) - Compute a concrete representation of a model instead of performing (OCamlPro/alt-ergo#925) - Allow direct access to the SAT API in the Alt-Ergo library computations during printing (OCamlPro/alt-ergo#927) - Better handling for step limit (OCamlPro/alt-ergo#936) - Add a generic option manager to deal with the dolmen state (OCamlPro/alt-ergo#951) - Expose an imperative SAT API in the Alt-Ergo library (OCamlPro/alt-ergo#962) - Keep track of the SMT-LIB mode (OCamlPro/alt-ergo#971) - Add ability to decide on semantic literals (OCamlPro/alt-ergo#1027, OCamlPro/alt-ergo#1118) - Preserve trigger order when parsing quantifiers with multiple trigger (OCamlPro/alt-ergo#1046). - Store domains inside the union-find module (OCamlPro/alt-ergo#1119) - Remove some polymorphic hashtables (OCamlPro/alt-ergo#1219) ### Build and integration - Drop support for OCaml <4.08.1 (OCamlPro/alt-ergo#803) - Use dune-site for the inequalities plugins. External pluginsm ust now be registered through the dune-site plugin mechanism in the `(alt-ergo plugins)` site to be picked up by Alt-Ergo (OCamlPro/alt-ergo#1049). - Add a release workflow (OCamlPro/alt-ergo#827) - Add a Windows workflow (OCamlPro/alt-ergo#1203) - Mark the dune.inc file as linguist-generated to avoid huge diffs (OCamlPro/alt-ergo#830) - Use GitHub Actions badges in the README (OCamlPro/alt-ergo#882) - Use `dune build @check` to build the project (OCamlPro/alt-ergo#887) - Enable warnings as errors on the CI (OCamlPro/alt-ergo#888) - Uniformization of internal identifiers generation (OCamlPro/alt-ergo#905, OCamlPro/alt-ergo#918) - Use an efficient `String.starts_with` implementation (OCamlPro/alt-ergo#912) - Fix the Makefile (OCamlPro/alt-ergo#914) - Add `Logs` dependency (OCamlPro/alt-ergo#1206) - Use `dynamic_include` to include the generated file `dune.inc` (OCamlPro/alt-ergo#1199) - Support Windows (OCamlPro/alt-ergo#1184,OCamlPro/alt-ergo#1189,OCamlPro/alt-ergo#1195,OCamlPro/alt-ergo#1199,OCamlPro/alt-ergo#1200) - Wrap the library `Alt_ergo_prelude` (OCamlPro/alt-ergo#1223) ### Testing - Use --enable-assertions in tests (OCamlPro/alt-ergo#809) - Add a test for push/pop (OCamlPro/alt-ergo#843) - Use the CDCL solver when testing model generation (OCamlPro/alt-ergo#938) - Do not test .smt2 files with the legacy frontend (OCamlPro/alt-ergo#939) - Restore automatic creation of .expected files (OCamlPro/alt-ergo#941) ### Documentation - Add a new example for model generation (OCamlPro/alt-ergo#826) - Add a Pygments lexer for the Alt-Ergo native language (OCamlPro/alt-ergo#862) - Update the current authors (OCamlPro/alt-ergo#865) - Documentation of the `Enum` theory (OCamlPro/alt-ergo#871) - Document `Th_util.lit_origin` (OCamlPro/alt-ergo#915) - Document the CDCL-Tableaux solver (OCamlPro/alt-ergo#995) - Document Windows support (OCamlPro/alt-ergo#1216) - Remove instructions to install Alt-Ergo on Debian (OCamlPro/alt-ergo#1217) - Document optimization feature (OCamlPro/alt-ergo#1231)

This was referenced Mar 29, 2024

feat(BV, CP): Add propagators for bvudiv and bvurem #1084

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feat(BV, CP): Add propagators for bvshl and bvlshr #1085

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bclement-ocp force-pushed the bvarith-poly branch from 265c0f1 to 23b6b07 Compare May 7, 2024 10:25

bclement-ocp force-pushed the bvarith-poly branch 4 times, most recently from a1fcf49 to d4431f8 Compare May 17, 2024 07:57

bclement-ocp force-pushed the bvarith-poly branch from d4431f8 to e7aed78 Compare June 11, 2024 16:10

bclement-ocp mentioned this pull request Jun 11, 2024

feat(BV): Do not store width in Bitlist #1144

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bclement-ocp force-pushed the bvarith-poly branch 3 times, most recently from 7d98a78 to 4eeb50a Compare June 12, 2024 17:17

This was referenced Jun 20, 2024

feat(BV, CP): Add bitlist propagators for add/sub #1151

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feat(BV): Only store domains on variable parts #1152

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bclement-ocp force-pushed the bvarith-poly branch 2 times, most recently from 2cd49d1 to a6f02de Compare June 20, 2024 14:07

bclement-ocp force-pushed the bvarith-poly branch from a6f02de to daf0c49 Compare June 21, 2024 08:45

Halbaroth reviewed Jun 21, 2024

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bclement-ocp commented Jun 21, 2024

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Halbaroth approved these changes Jun 21, 2024

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bclement-ocp merged commit 0a46f32 into OCamlPro:next Jun 21, 2024
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bclement-ocp deleted the bvarith-poly branch June 21, 2024 15:39

bclement-ocp added this to the 2.6.0 milestone Jul 11, 2024

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[new release] alt-ergo (4 packages) (2.6.0) ocaml/opam-repository#26609

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feat(BV, CP): Propagators for addition and multiplication #1083

feat(BV, CP): Propagators for addition and multiplication #1083

bclement-ocp commented Mar 29, 2024

bclement-ocp commented May 7, 2024

Halbaroth commented Jun 21, 2024

bclement-ocp commented Jun 21, 2024

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feat(BV, CP): Propagators for addition and multiplication #1083

feat(BV, CP): Propagators for addition and multiplication #1083

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