Refactor bv-abstraction preprocessing pass. (#1860)

4 files changed, 124 insertions, 0 deletions

diff --git a/src/preprocessing/passes/bv_abstraction.cpp b/src/preprocessing/passes/bv_abstraction.cpp
new file mode 100644
index 000000000..27069de2f
--- /dev/null
+++ b/src/preprocessing/passes/bv_abstraction.cpp
@@ -0,0 +1,65 @@
+/*********************                                                        */
+/*! \file bv_abstraction.cpp
+ ** \verbatim
+ ** Top contributors (to current version):
+ **   Mathias Preiner
+ ** This file is part of the CVC4 project.
+ ** Copyright (c) 2009-2018 by the authors listed in the file AUTHORS
+ ** in the top-level source directory) and their institutional affiliations.
+ ** All rights reserved.  See the file COPYING in the top-level source
+ ** directory for licensing information.\endverbatim
+ **
+ ** \brief The BvAbstraction preprocessing pass
+ **
+ ** Abstract common structures over small domains to UF. This preprocessing
+ ** is particularly useful on QF_BV/mcm benchmarks and can be enabled via
+ ** option `--bv-abstraction`.
+ ** For more information see 3.4 Refactoring Isomorphic Circuits in [1].
+ **
+ ** [1] Liana Hadarean, An Efficient and Trustworthy Theory Solver for
+ **     Bit-vectors in Satisfiability Modulo Theories
+ **     https://cs.nyu.edu/media/publications/hadarean_liana.pdf
+ **/
+
+#include "preprocessing/passes/bv_abstraction.h"
+
+#include <vector>
+
+#include "options/bv_options.h"
+#include "theory/bv/theory_bv.h"
+#include "theory/rewriter.h"
+
+namespace CVC4 {
+namespace preprocessing {
+namespace passes {
+
+using namespace CVC4::theory;
+
+BvAbstraction::BvAbstraction(PreprocessingPassContext* preprocContext)
+    : PreprocessingPass(preprocContext, "bv-abstraction"){};
+
+PreprocessingPassResult BvAbstraction::applyInternal(
+    AssertionPipeline* assertionsToPreprocess)
+{
+  std::vector<Node> new_assertions;
+  std::vector<Node> assertions(assertionsToPreprocess->begin(),
+                               assertionsToPreprocess->end());
+  TheoryEngine* te = d_preprocContext->getTheoryEngine();
+  bv::TheoryBV* bv_theory = static_cast<bv::TheoryBV*>(te->theoryOf(THEORY_BV));
+  bool changed = bv_theory->applyAbstraction(assertions, new_assertions);
+  for (unsigned i = 0, size = assertionsToPreprocess->size(); i < size; ++i)
+  {
+    assertionsToPreprocess->replace(i, Rewriter::rewrite(new_assertions[i]));
+  }
+  // If we are using the lazy solver and the abstraction applies, then UF
+  // symbols were introduced.
+  if (options::bitblastMode() == bv::BITBLAST_MODE_LAZY && changed)
+  {
+    d_preprocContext->widenLogic(theory::THEORY_UF);
+  }
+  return PreprocessingPassResult::NO_CONFLICT;
+}
+
+}  // namespace passes
+}  // namespace preprocessing
+}  // namespace CVC4
diff --git a/src/preprocessing/passes/bv_abstraction.h b/src/preprocessing/passes/bv_abstraction.h
new file mode 100644
index 000000000..67e2ef296
--- /dev/null
+++ b/src/preprocessing/passes/bv_abstraction.h
@@ -0,0 +1,50 @@
+/*********************                                                        */
+/*! \file bv_abstraction.h
+ ** \verbatim
+ ** Top contributors (to current version):
+ **   Mathias Preiner
+ ** This file is part of the CVC4 project.
+ ** Copyright (c) 2009-2018 by the authors listed in the file AUTHORS
+ ** in the top-level source directory) and their institutional affiliations.
+ ** All rights reserved.  See the file COPYING in the top-level source
+ ** directory for licensing information.\endverbatim
+ **
+ ** \brief The BvAbstraction preprocessing pass
+ **
+ ** Abstract common structures over small domains to UF. This preprocessing
+ ** is particularly useful on QF_BV/mcm benchmarks and can be enabled via
+ ** option `--bv-abstraction`.
+ ** For more information see 3.4 Refactoring Isomorphic Circuits in [1].
+ **
+ ** [1] Liana Hadarean, An Efficient and Trustworthy Theory Solver for
+ **     Bit-vectors in Satisfiability Modulo Theories
+ **     https://cs.nyu.edu/media/publications/hadarean_liana.pdf
+ **/
+
+#include "cvc4_private.h"
+
+#ifndef __CVC4__PREPROCESSING__PASSES__BV_ABSTRACTION_H
+#define __CVC4__PREPROCESSING__PASSES__BV_ABSTRACTION_H
+
+#include "preprocessing/preprocessing_pass.h"
+#include "preprocessing/preprocessing_pass_context.h"
+
+namespace CVC4 {
+namespace preprocessing {
+namespace passes {
+
+class BvAbstraction : public PreprocessingPass
+{
+ public:
+  BvAbstraction(PreprocessingPassContext* preprocContext);
+
+ protected:
+  PreprocessingPassResult applyInternal(
+      AssertionPipeline* assertionsToPreprocess) override;
+};
+
+}  // namespace passes
+}  // namespace preprocessing
+}  // namespace CVC4
+
+#endif /* __CVC4__PREPROCESSING__PASSES__BV_ABSTRACTION_H */
diff --git a/src/preprocessing/preprocessing_pass_context.cpp b/src/preprocessing/preprocessing_pass_context.cpp
index a738f9484..7d2ceab2e 100644
--- a/src/preprocessing/preprocessing_pass_context.cpp
+++ b/src/preprocessing/preprocessing_pass_context.cpp
@@ -22,5 +22,11 @@ namespace preprocessing {
 PreprocessingPassContext::PreprocessingPassContext(SmtEngine* smt)
     : d_smt(smt) {}
 
+void PreprocessingPassContext::widenLogic(theory::TheoryId id)
+{
+  LogicRequest req(*d_smt);
+  req.widenLogic(id);
+}
+
 }  // namespace preprocessing
 }  // namespace CVC4
diff --git a/src/preprocessing/preprocessing_pass_context.h b/src/preprocessing/preprocessing_pass_context.h
index 66f4d9297..28f51d154 100644
--- a/src/preprocessing/preprocessing_pass_context.h
+++ b/src/preprocessing/preprocessing_pass_context.h
@@ -38,6 +38,9 @@ class PreprocessingPassContext {
   prop::PropEngine* getPropEngine() { return d_smt->d_propEngine; }
   context::Context* getUserContext() { return d_smt->d_userContext; }
 
+  /* Widen the logic to include the given theory. */
+  void widenLogic(theory::TheoryId id);
+
  private:
   /* Pointer to the SmtEngine that this context was created in. */
   SmtEngine* d_smt;