remove unnecessary parameter copies

src/ast/array_decl_plugin.cpp

@@ -49,7 +49,7 @@ sort * array_decl_plugin::mk_sort(decl_kind k, unsigned num_parameters, paramete
             m_manager->raise_exception("invalid array sort definition, invalid number of parameters");
             return nullptr;
         }
-        parameter params[2] = { parameters[0], parameter(m_manager->mk_bool_sort()) };
+        parameter params[2] = { parameter(parameters[0]), parameter(m_manager->mk_bool_sort()) };
         return mk_sort(ARRAY_SORT, 2, params);
     }
     SASSERT(k == ARRAY_SORT);

src/ast/ast.cpp

@@ -48,21 +48,13 @@ parameter::~parameter() {
     }
 }
 
-parameter& parameter::operator=(parameter const& other) {
-    if (this == &other) {
-        return *this;
-    }
-
-    this->~parameter();
-    m_val = other.m_val;
-
+parameter::parameter(parameter const& other) : m_val(other.m_val) {
     if (auto p = std::get_if<rational*>(&m_val)) {
         m_val = alloc(rational, **p);
     }
     if (auto p = std::get_if<zstring*>(&m_val)) {
         m_val = alloc(zstring, **p);
     }
-    return *this;
 }
 
 void parameter::init_eh(ast_manager & m) {

src/ast/ast.h

@@ -142,15 +142,18 @@ class parameter {
     explicit parameter(const char *s): m_val(symbol(s)) {}
     explicit parameter(const std::string &s): m_val(symbol(s)) {}
     explicit parameter(unsigned ext_id, bool): m_val(ext_id) {}
-    parameter(parameter const& other) { *this = other; }
+    explicit parameter(parameter const& other);
 
     parameter(parameter && other) noexcept : m_val(std::move(other.m_val)) {
         other.m_val = 0;
     }
 
     ~parameter();
 
-    parameter& operator=(parameter const& other);
+    parameter& operator=(parameter && other) {
+        std::swap(other.m_val, m_val);
+        return *this;
+    }
 
     kind_t get_kind() const { return static_cast<kind_t>(m_val.index()); }
     bool is_int() const { return get_kind() == PARAM_INT; }
@@ -1099,7 +1102,7 @@ class decl_plugin {
 
     // Event handlers for deleting/translating PARAM_EXTERNAL
     virtual void del(parameter const & p) {}
-    virtual parameter translate(parameter const & p, decl_plugin & target) { UNREACHABLE(); return p; }
+    virtual parameter translate(parameter const & p, decl_plugin & target) { UNREACHABLE(); return {}; }
 
     virtual bool is_considered_uninterpreted(func_decl * f) { return false; }
 };

src/ast/ast_lt.cpp

@@ -68,8 +68,8 @@ bool lt(ast * n1, ast * n2) {
         num = to_sort(n1)->get_num_parameters();
         SASSERT(num > 0);
         for (unsigned i = 0; i < num; i++) {
-            parameter p1 = to_sort(n1)->get_parameter(i);
-            parameter p2 = to_sort(n2)->get_parameter(i);
+            const parameter &p1 = to_sort(n1)->get_parameter(i);
+            const parameter &p2 = to_sort(n2)->get_parameter(i);
             check_parameter(p1, p2);
         }
         UNREACHABLE();
@@ -80,8 +80,8 @@ bool lt(ast * n1, ast * n2) {
         check_value(to_func_decl(n1)->get_num_parameters(), to_func_decl(n2)->get_num_parameters());
         num = to_func_decl(n1)->get_num_parameters();
         for (unsigned i = 0; i < num; i++) {
-            parameter p1 = to_func_decl(n1)->get_parameter(i);
-            parameter p2 = to_func_decl(n2)->get_parameter(i);
+            const parameter &p1 = to_func_decl(n1)->get_parameter(i);
+            const parameter &p2 = to_func_decl(n2)->get_parameter(i);
             check_parameter(p1, p2);
         }
         num = to_func_decl(n1)->get_arity();

src/ast/bv_decl_plugin.cpp

@@ -454,9 +454,8 @@ func_decl * bv_decl_plugin::mk_num_decl(unsigned num_parameters, parameter const
     // This cannot be enforced now, since some Z3 modules try to generate these invalid numerals.
     // After SMT-COMP, I should find all offending modules.
     // For now, I will just simplify the numeral here.
-    rational v = parameters[0].get_rational();
-    parameter p0(mod2k(v, bv_size));
-    parameter ps[2] = { std::move(p0), parameters[1] };
+    const rational &v = parameters[0].get_rational();
+    parameter ps[2] = { parameter(mod2k(v, bv_size)), parameter(parameters[1]) };
     sort * bv = get_bv_sort(bv_size);
     return m_manager->mk_const_decl(m_bv_sym, bv, func_decl_info(m_family_id, OP_BV_NUM, num_parameters, ps));
 }

src/ast/fpa/bv2fpa_converter.cpp

@@ -319,7 +319,7 @@ func_interp * bv2fpa_converter::convert_func_interp(model_core * mc, func_decl *
 
         if (m_fpa_util.is_to_sbv(f) || m_fpa_util.is_to_ubv(f)) {
             auto k = m_fpa_util.is_to_sbv(f) ? OP_FPA_TO_SBV_I : OP_FPA_TO_UBV_I;
-            parameter param = f->get_parameter(0);
+            const parameter &param = f->get_parameter(0);
             func_decl_ref to_bv_i(m.mk_func_decl(fid, k, 1, &param, dom.size(), dom.data()), m);
             expr_ref else_value(m.mk_app(to_bv_i, dom.size(), dom.data()), m);
             result->set_else(else_value);

src/ast/fpa_decl_plugin.cpp

@@ -208,8 +208,7 @@ sort * fpa_decl_plugin::mk_float_sort(unsigned ebits, unsigned sbits) {
     if (ebits > 63)
         m_manager->raise_exception("maximum number of exponent bits is 63");
 
-    parameter p1(ebits), p2(sbits);
-    parameter ps[2] = { p1, p2 };
+    parameter ps[2] = { parameter(ebits), parameter(sbits) };
     sort_size sz;
     sz = sort_size::mk_very_big(); // TODO: refine
     return m_manager->mk_sort(symbol("FloatingPoint"), sort_info(m_family_id, FLOATING_POINT_SORT, sz, 2, ps));

src/ast/polymorphism_util.cpp

@@ -40,7 +40,7 @@ namespace polymorphism {
         unsigned n = s->get_num_parameters();
         vector<parameter> ps;
         for (unsigned i = 0; i < n; ++i) {
-            auto p = s->get_parameter(i);
+            auto &p = s->get_parameter(i);
             if (p.is_ast() && is_sort(p.get_ast())) {
                 sort_ref s = (*this)(to_sort(p.get_ast()));
                 ps.push_back(parameter(s.get()));
@@ -167,8 +167,8 @@ namespace polymorphism {
         if (s1->get_num_parameters() != s2->get_num_parameters())
             return false;
         for (unsigned i = s1->get_num_parameters(); i-- > 0;) {
-            auto p1 = s1->get_parameter(i);
-            auto p2 = s2->get_parameter(i);
+            auto &p1 = s1->get_parameter(i);
+            auto &p2 = s2->get_parameter(i);
             if (p1.is_ast() && is_sort(p1.get_ast())) {
                 if (!p2.is_ast())
                     return false;
@@ -204,8 +204,8 @@ namespace polymorphism {
         if (s1->get_num_parameters() != s2->get_num_parameters())
             return false;
         for (unsigned i = s1->get_num_parameters(); i-- > 0;) {
-            auto p1 = s1->get_parameter(i);
-            auto p2 = s2->get_parameter(i);
+            auto &p1 = s1->get_parameter(i);
+            auto &p2 = s2->get_parameter(i);
             if (p1.is_ast() && is_sort(p1.get_ast())) {
                 if (!p2.is_ast())
                     return false;
@@ -282,7 +282,7 @@ namespace polymorphism {
         }
         vector<parameter> params;
         for (unsigned i = 0; i < s->get_num_parameters(); ++i) {
-            parameter p = s->get_parameter(i);
+            const parameter &p = s->get_parameter(i);
             if (p.is_ast() && is_sort(p.get_ast())) {
                 sort_ref fs = fresh(to_sort(p.get_ast()));
                 params.push_back(parameter(fs.get()));

src/muz/spacer/spacer_proof_utils.cpp

@@ -209,18 +209,14 @@ namespace spacer {
 
     static proof_ref  mk_th_lemma(ast_manager &m, ptr_buffer<proof> const &parents,
                                   unsigned num_params, parameter const *params) {
-        buffer<parameter> v;
-        for (unsigned i = 1; i < num_params; ++i)
-            v.push_back(params[i]);
-
         SASSERT(params[0].is_symbol());
         family_id tid = m.mk_family_id(params[0].get_symbol());
         SASSERT(tid != null_family_id);
 
         proof_ref pf(m);
         pf =  m.mk_th_lemma(tid, m.mk_false(),
                             parents.size(), parents.data(),
-                            v.size(), v.data());
+                            num_params - 1, params + 1);
         return pf;
     }