more bugfixes, some basic propagation, and testcases to cover them

12 files changed, 141 insertions, 13 deletions

diff --git a/src/prop/cnf_stream.cpp b/src/prop/cnf_stream.cpp
index 0c692501f..99cd26297 100644
--- a/src/prop/cnf_stream.cpp
+++ b/src/prop/cnf_stream.cpp
@@ -147,7 +147,7 @@ SatLiteral CnfStream::convertAtom(TNode node) {
 
 SatLiteral CnfStream::getLiteral(TNode node) {
   TranslationCache::iterator find = d_translationCache.find(node);
-  Assert(find != d_translationCache.end(), "Literal not in the CNF Cache");
+  Assert(find != d_translationCache.end(), "Literal not in the CNF Cache: ", node.toString().c_str());
   SatLiteral literal = find->second.literal;
   Debug("cnf") << "CnfStream::getLiteral(" << node << ") => " << literal << std::endl;
   return literal;
diff --git a/src/theory/bv/equality_engine.h b/src/theory/bv/equality_engine.h
index 6fa1b7d22..5d4212849 100644
--- a/src/theory/bv/equality_engine.h
+++ b/src/theory/bv/equality_engine.h
@@ -30,6 +30,7 @@
 #include "util/output.h"
 #include "util/stats.h"
 #include "theory/rewriter.h"
+#include "theory/bv/theory_bv_utils.h"
 
 namespace CVC4 {
 namespace theory {
@@ -447,7 +448,11 @@ bool EqualityEngine<OwnerClass, NotifyClass, UnionFindPreferences>::addEquality(
   // Check for constants
   if (d_nodes[t1classId].getMetaKind() == kind::metakind::CONSTANT &&
       d_nodes[t2classId].getMetaKind() == kind::metakind::CONSTANT) {
-    d_notify.conflict(reason);
+    std::vector<TNode> reasons;
+    getExplanation(t1, d_nodes[t1classId], reasons);
+    getExplanation(t2, d_nodes[t2classId], reasons);
+    reasons.push_back(reason);
+    d_notify.conflict(utils::mkAnd(reasons));
     return false;
   }
 
@@ -665,12 +670,13 @@ std::string EqualityEngine<OwnerClass, NotifyClass, UnionFindPreferences>::edges
 
 template <typename OwnerClass, typename NotifyClass, typename UnionFindPreferences>
 void EqualityEngine<OwnerClass, NotifyClass, UnionFindPreferences>::getExplanation(TNode t1, TNode t2, std::vector<TNode>& equalities) const {
-  Assert(equalities.empty());
-  Assert(t1 != t2);
   Assert(getRepresentative(t1) == getRepresentative(t2));
 
   Debug("equality") << "EqualityEngine::getExplanation(" << t1 << "," << t2 << ")" << std::endl;
 
+  // If the nodes are the same, we're done
+  if (t1 == t2) return;
+
   const_cast<EqualityEngine*>(this)->backtrack();
 
   // Queue for the BFS containing nodes
diff --git a/src/theory/bv/kinds b/src/theory/bv/kinds
index 2df4c361c..381e90d47 100644
--- a/src/theory/bv/kinds
+++ b/src/theory/bv/kinds
@@ -6,7 +6,7 @@
 
 theory THEORY_BV ::CVC4::theory::bv::TheoryBV "theory/bv/theory_bv.h"
 
-properties finite check  
+properties finite check propagate
 
 rewriter ::CVC4::theory::bv::TheoryBVRewriter "theory/bv/theory_bv_rewriter.h"
 
diff --git a/src/theory/bv/theory_bv.cpp b/src/theory/bv/theory_bv.cpp
index 2d989a563..51de8df28 100644
--- a/src/theory/bv/theory_bv.cpp
+++ b/src/theory/bv/theory_bv.cpp
@@ -139,10 +139,12 @@ bool TheoryBV::triggerEquality(size_t triggerId) {
   // If we have a negation asserted, we have a confict
   if (d_assertions.contains(equality.notNode())) {
 
-    vector<TNode> assertions;
-    d_eqEngine.getExplanation(equality[0], equality[1], assertions);
-    assertions.push_back(equality.notNode());
-    d_out->conflict(mkAnd(assertions));
+    std::vector<TNode> explanation;
+    d_eqEngine.getExplanation(equality[0], equality[1], explanation);
+    std::set<TNode> assumptions;
+    assumptions.insert(equality.notNode());
+    utils::getConjuncts(explanation, assumptions);
+    d_out->conflict(utils::mkConjunction(assumptions));
 
     return false;
   }
@@ -169,3 +171,16 @@ Node TheoryBV::getValue(TNode n, Valuation* valuation) {
     Unhandled(n.getKind());
   }
 }
+
+void TheoryBV::explain(TNode node) {
+  Debug("bitvector") << "TheoryBV::explain(" << node << ")" << std::endl;
+  if(node.getKind() == kind::EQUAL) {
+    std::vector<TNode> reasons;
+    d_eqEngine.getExplanation(node[0], node[1], reasons);
+    std::set<TNode> simpleReasons;
+    utils::getConjuncts(reasons, simpleReasons);
+    d_out->explanation(utils::mkConjunction(simpleReasons));
+    return;
+  }
+  Unreachable();
+}
diff --git a/src/theory/bv/theory_bv.h b/src/theory/bv/theory_bv.h
index 474c4d0cd..f2c2fa332 100644
--- a/src/theory/bv/theory_bv.h
+++ b/src/theory/bv/theory_bv.h
@@ -45,7 +45,9 @@ public:
       return d_theoryBV.triggerEquality(triggerId);
     }
     void conflict(Node explanation) {
-      d_theoryBV.d_out->conflict(explanation);
+      std::set<TNode> assumptions;
+      utils::getConjuncts(explanation, assumptions);
+      d_theoryBV.d_out->conflict(utils::mkConjunction(assumptions));
     }
   };
 
@@ -119,7 +121,7 @@ public:
 
   void propagate(Effort e) { }
 
-  void explain(TNode n) { }
+  void explain(TNode n);
 
   Node getValue(TNode n, Valuation* valuation);
 
diff --git a/src/theory/bv/theory_bv_utils.h b/src/theory/bv/theory_bv_utils.h
index ad924f8a0..781b5cddb 100644
--- a/src/theory/bv/theory_bv_utils.h
+++ b/src/theory/bv/theory_bv_utils.h
@@ -50,7 +50,11 @@ inline Node mkFalse() {
 }
 
 inline Node mkAnd(std::vector<TNode>& children) {
-  return NodeManager::currentNM()->mkNode(kind::AND, children);
+  if (children.size() > 1) {
+    return NodeManager::currentNM()->mkNode(kind::AND, children);
+  } else {
+    return children[0];
+  }
 }
 
 inline Node mkAnd(std::vector<Node>& children) {
@@ -90,6 +94,13 @@ inline void getConjuncts(TNode node, std::set<TNode>& conjuncts) {
   }
 }
 
+inline void getConjuncts(std::vector<TNode>& nodes, std::set<TNode>& conjuncts) {
+  for (unsigned i = 0, i_end = nodes.size(); i < i_end; ++ i) {
+    getConjuncts(nodes[i], conjuncts);
+  }
+}
+
+
 inline Node mkConjunction(const std::set<TNode> nodes) {
   std::set<TNode> expandedNodes;
 
diff --git a/test/regress/regress0/bv/core/Makefile.am b/test/regress/regress0/bv/core/Makefile.am
index 9182bfbc6..e204a29b5 100644
--- a/test/regress/regress0/bv/core/Makefile.am
+++ b/test/regress/regress0/bv/core/Makefile.am
@@ -64,7 +64,12 @@ TESTS =	\
 	slice-19.smt \
 	slice-20.smt \
 	ext_con_004_001_1024.smt \
-	a78test0002.smt
+	a78test0002.smt \
+	a95test0002.smt \
+	bitvec0.smt \
+	bitvec2.smt \
+	bitvec3.smt \
+	bitvec5.smt 
 			
 EXTRA_DIST = $(TESTS)
 
diff --git a/test/regress/regress0/bv/core/a95test0002.smt b/test/regress/regress0/bv/core/a95test0002.smt
new file mode 100644
index 000000000..3a4862a24
--- /dev/null
+++ b/test/regress/regress0/bv/core/a95test0002.smt
@@ -0,0 +1,17 @@
+(benchmark a95test0002.smt
+  :source {
+Bit-vector benchmarks from Dawson Engler's tool contributed by Vijay Ganesh
+(vganesh@stanford.edu).  Translated into SMT-LIB format by Clark Barrett using
+CVC3.
+
+}
+  :status sat
+  :difficulty { 0 }
+  :category { industrial }
+  :logic QF_BV
+  :extrafuns ((a BitVec[32]))
+  :assumption
+(not (not (= (concat bv0[16] (extract[15:0] a)) a)))
+  :formula
+(not false)
+)
diff --git a/test/regress/regress0/bv/core/bitvec1.smt b/test/regress/regress0/bv/core/bitvec1.smt
new file mode 100644
index 000000000..345bc6e6d
--- /dev/null
+++ b/test/regress/regress0/bv/core/bitvec1.smt
@@ -0,0 +1,18 @@
+(benchmark bitvec1.smt
+  :source {
+Hand-crafted bit-vector benchmarks.  Some are from the SVC benchmark suite.
+Contributed by Vijay Ganesh (vganesh@stanford.edu).  Translated into SMT-LIB
+format by Clark Barrett using CVC3.
+
+}
+  :status unsat
+  :difficulty { 0 }
+  :category { crafted }
+  :logic QF_BV
+  :extrafuns ((a BitVec[32]))
+  :extrafuns ((b BitVec[32]))
+  :extrafuns ((c BitVec[32]))
+  :extrafuns ((res BitVec[32]))
+  :formula
+(flet ($cvc_1 (= (extract[0:0] a) bv1[1])) (flet ($cvc_2 (= (extract[0:0] b) bv1[1])) (let (?cvc_0 (extract[0:0] c)) (flet ($cvc_6 (= ?cvc_0 bv1[1])) (let (?cvc_3 (extract[0:0] res)) (flet ($cvc_4 (= (extract[1:1] a) bv1[1])) (flet ($cvc_5 (= (extract[1:1] b) bv1[1])) (flet ($cvc_8 (if_then_else $cvc_4 (not $cvc_5) $cvc_5)) (let (?cvc_7 (extract[1:1] c)) (let (?cvc_9 (extract[1:1] res)) (not (implies (and (and (and (= (extract[1:0] a) bv1[2]) (= (extract[1:0] b) bv1[2])) (and (if_then_else (and $cvc_1 $cvc_2) $cvc_6 (= ?cvc_0 bv0[1])) (if_then_else (if_then_else $cvc_1 (not $cvc_2) $cvc_2) (= ?cvc_3 bv1[1]) (= ?cvc_3 bv0[1])))) (and (if_then_else (or (and $cvc_4 $cvc_5)  (and $cvc_8 $cvc_6) ) (= ?cvc_7 bv1[1]) (= ?cvc_7 bv0[1])) (if_then_else (if_then_else $cvc_6 (not $cvc_8) $cvc_8) (= ?cvc_9 bv1[1]) (= ?cvc_9 bv0[1])))) (and (= (extract[1:0] res) bv2[2]) (= (extract[1:0] c) bv1[2]))))))))))))))
+)
diff --git a/test/regress/regress0/bv/core/bitvec2.smt b/test/regress/regress0/bv/core/bitvec2.smt
new file mode 100644
index 000000000..bb479a5f8
--- /dev/null
+++ b/test/regress/regress0/bv/core/bitvec2.smt
@@ -0,0 +1,15 @@
+(benchmark bitvec2.smt
+  :source {
+Hand-crafted bit-vector benchmarks.  Some are from the SVC benchmark suite.
+Contributed by Vijay Ganesh (vganesh@stanford.edu).  Translated into SMT-LIB
+format by Clark Barrett using CVC3.
+
+}
+  :status unsat
+  :difficulty { 0 }
+  :category { crafted }
+  :logic QF_BV
+  :extrapreds ((a))
+  :formula
+(not (= (concat bv1[1] (ite a bv0[1] bv1[1])) (ite a bv2[2] bv3[2])))
+)
diff --git a/test/regress/regress0/bv/core/bitvec3.smt b/test/regress/regress0/bv/core/bitvec3.smt
new file mode 100644
index 000000000..054ec25ac
--- /dev/null
+++ b/test/regress/regress0/bv/core/bitvec3.smt
@@ -0,0 +1,20 @@
+(benchmark bitvec3.smt
+  :source {
+Hand-crafted bit-vector benchmarks.  Some are from the SVC benchmark suite.
+Contributed by Vijay Ganesh (vganesh@stanford.edu).  Translated into SMT-LIB
+format by Clark Barrett using CVC3.
+
+}
+  :status unsat
+  :difficulty { 0 }
+  :category { crafted }
+  :logic QF_BV
+  :extrafuns ((a BitVec[32]))
+  :extrafuns ((b BitVec[32]))
+  :extrafuns ((c1 BitVec[32]))
+  :extrafuns ((c2 BitVec[32]))
+  :extrafuns ((out BitVec[32]))
+  :extrafuns ((carry BitVec[32]))
+  :formula
+(let (?cvc_0 (extract[1:0] b)) (let (?cvc_1 (extract[2:0] c1)) (let (?cvc_3 (concat bv0[1] bv0[2])) (let (?cvc_2 (extract[2:0] c2)) (flet ($cvc_4 (= (extract[0:0] c1) bv1[1])) (flet ($cvc_5 (= (extract[0:0] c2) bv1[1])) (let (?cvc_6 (extract[0:0] carry)) (let (?cvc_7 (extract[1:1] c1)) (flet ($cvc_11 (= ?cvc_7 bv1[1])) (let (?cvc_8 (extract[1:1] c2)) (flet ($cvc_10 (= ?cvc_8 bv0[1])) (flet ($cvc_9 (= ?cvc_7 bv0[1])) (flet ($cvc_12 (= ?cvc_8 bv1[1])) (flet ($cvc_14 (or (and $cvc_11 $cvc_10)  (and $cvc_9 $cvc_12) )) (flet ($cvc_13 (= ?cvc_6 bv1[1])) (let (?cvc_15 (extract[1:1] carry)) (let (?cvc_16 (extract[2:2] c1)) (flet ($cvc_20 (= ?cvc_16 bv1[1])) (let (?cvc_17 (extract[2:2] c2)) (flet ($cvc_19 (= ?cvc_17 bv0[1])) (flet ($cvc_18 (= ?cvc_16 bv0[1])) (flet ($cvc_21 (= ?cvc_17 bv1[1])) (flet ($cvc_22 (= ?cvc_15 bv1[1])) (not (implies (and (= (extract[1:0] a) bv3[2]) (= ?cvc_0 bv3[2])) (implies (and (and (and (and (and (and (and (if_then_else (= (extract[0:0] a) bv1[1]) (= ?cvc_1 (concat bv0[1] ?cvc_0)) (= ?cvc_1 ?cvc_3)) (if_then_else (= (extract[1:1] a) bv1[1]) (= ?cvc_2 (concat ?cvc_0 bv0[1])) (= ?cvc_2 ?cvc_3))) (= (extract[0:0] out) (ite (or $cvc_4  $cvc_5 ) bv1[1] bv0[1]))) (= ?cvc_6 (ite (and $cvc_4 $cvc_5) bv1[1] bv0[1]))) (= (extract[1:1] out) (ite (or (and (= ?cvc_6 bv0[1]) $cvc_14)  (and $cvc_13 (and $cvc_9 $cvc_10)) ) bv1[1] bv0[1]))) (= ?cvc_15 (ite (or (and $cvc_11 $cvc_12)  (and $cvc_13 $cvc_14) ) bv1[1] bv0[1]))) (= (extract[2:2] out) (ite (or (and (= ?cvc_15 bv0[1]) (or (and $cvc_20 $cvc_19)  (and $cvc_18 $cvc_21) ))  (and $cvc_22 (and $cvc_18 $cvc_19)) ) bv1[1] bv0[1]))) (= (extract[2:2] carry) (ite (or (and $cvc_20 $cvc_21)  (and $cvc_22 (or $cvc_20  $cvc_21 )) ) bv1[1] bv0[1]))) (and (= (extract[2:0] out) bv1[3]) (= (extract[2:0] carry) bv6[3]))))))))))))))))))))))))))))
+)
diff --git a/test/regress/regress0/bv/core/bitvec5.smt b/test/regress/regress0/bv/core/bitvec5.smt
new file mode 100644
index 000000000..3b6f2f3b9
--- /dev/null
+++ b/test/regress/regress0/bv/core/bitvec5.smt
@@ -0,0 +1,19 @@
+(benchmark bitvec5.smt
+  :source {
+Hand-crafted bit-vector benchmarks.  Some are from the SVC benchmark suite.
+Contributed by Vijay Ganesh (vganesh@stanford.edu).  Translated into SMT-LIB
+format by Clark Barrett using CVC3.
+
+}
+  :status unsat
+  :difficulty { 0 }
+  :category { crafted }
+  :logic QF_BV
+  :extrafuns ((a BitVec[32]))
+  :extrafuns ((b BitVec[32]))
+  :extrafuns ((c BitVec[32]))
+  :extrafuns ((d BitVec[32]))
+  :extrafuns ((e BitVec[32]))
+  :formula
+(not (and (implies (and (and (= (extract[31:0] a) (extract[31:0] b)) (= (extract[31:16] a) (extract[15:0] c))) (= (extract[31:8] b) (extract[23:0] d))) (= (extract[11:8] c) (extract[19:16] d))) (implies (= (extract[30:0] e) (extract[31:1] e)) (= (extract[0:0] e) (extract[31:31] e)))))
+)