only allow flip if it doesn't increase unsat score

Signed-off-by: Nikolaj Bjorner <[email protected]>
Z3Prover · Jan 2, 2025 · f67e1b8 · f67e1b8
1 parent 814d7f4
commit f67e1b8
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diff --git a/src/ast/rewriter/bool_rewriter.cpp b/src/ast/rewriter/bool_rewriter.cpp
@@ -729,6 +729,8 @@ br_status bool_rewriter::mk_eq_core(expr * lhs, expr * rhs, expr_ref & result) {
         return BR_REWRITE1;
 
     if (m_ite_extra_rules) {
+        expr* c1, * t1, * e1;
+        expr* c2, * t2, * e2;
         if (m().is_ite(lhs) && m().is_value(rhs)) {
             r = try_ite_value(to_app(lhs), to_app(rhs), result);
             CTRACE("try_ite_value", r != BR_FAILED,
@@ -739,6 +741,16 @@ br_status bool_rewriter::mk_eq_core(expr * lhs, expr * rhs, expr_ref & result) {
             CTRACE("try_ite_value", r != BR_FAILED,
                    tout << mk_bounded_pp(lhs, m()) << "\n" << mk_bounded_pp(rhs, m()) << "\n--->\n" << mk_bounded_pp(result, m()) << "\n";);
         }
+        else if (m().is_ite(lhs, c1, t1, e1) && m().is_ite(rhs, c2, t2, e2) &&
+            m().is_value(t1) && m().is_value(e1) && m().is_value(t2) && m().is_value(e2)) {
+            expr_ref_vector args(m());
+            args.push_back(m().mk_or(c1, c2, m().mk_eq(e1, e2)));
+            args.push_back(m().mk_or(m().mk_not(c1), m().mk_not(c2), m().mk_eq(t1, t2)));
+            args.push_back(m().mk_or(m().mk_not(c1), c2, m().mk_eq(t1, e2)));
+            args.push_back(m().mk_or(c1, m().mk_not(c2), m().mk_eq(e1, t2)));
+            result = m().mk_and(args);
+            return BR_REWRITE_FULL;
+        }
         if (r != BR_FAILED)
             return r;
     }

diff --git a/src/ast/rewriter/bv_rewriter.cpp b/src/ast/rewriter/bv_rewriter.cpp
@@ -2934,6 +2934,7 @@ br_status bv_rewriter::mk_eq_core(expr * lhs, expr * rhs, expr_ref & result) {
         return BR_DONE;
     }
 
+
     return BR_FAILED;
 }
 

diff --git a/src/ast/sls/sls_bv_lookahead.cpp b/src/ast/sls/sls_bv_lookahead.cpp
@@ -553,8 +553,11 @@ namespace sls {
                             continue;
                         if (ctx.is_true(v) == v1)
                             continue;
+                        unsigned num_unsat = ctx.unsat().size();
                         TRACE("bv", tout << "update flip " << mk_bounded_pp(e, m) << "\n";);
                         ctx.flip(v);
+                        if (num_unsat < ctx.unsat().size())
+                            ctx.flip(v);
                     }
                     m_ev.set_bool_value(to_app(e), v1);
                 }
-Original file line number
+Diff line change
@@ Expand Up @@
             return BR_DONE;
         }
         return BR_FAILED;
     }
@@ Expand Down @@