fixes to bugs exposed by regressions

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

src/ast/pb_decl_plugin.cpp

@@ -118,8 +118,8 @@ app * pb_util::mk_at_most_k(unsigned num_args, expr * const * args, unsigned k)
     return m.mk_app(m_fid, OP_AT_MOST_K, 1, &param, num_args, args, m.mk_bool_sort());
 }
 
-bool pb_util::is_at_most_k(app *a) const {
-    return is_app_of(a, m_fid, OP_AT_MOST_K);
+bool pb_util::is_at_most_k(func_decl *a) const {
+    return is_decl_of(a, m_fid, OP_AT_MOST_K);
 }
 
 bool pb_util::is_at_most_k(app *a, rational& k) const {
@@ -138,8 +138,8 @@ app * pb_util::mk_at_least_k(unsigned num_args, expr * const * args, unsigned k)
     return m.mk_app(m_fid, OP_AT_LEAST_K, 1, &param, num_args, args, m.mk_bool_sort());
 }
 
-bool pb_util::is_at_least_k(app *a) const {
-    return is_app_of(a, m_fid, OP_AT_LEAST_K);
+bool pb_util::is_at_least_k(func_decl *a) const {
+    return is_decl_of(a, m_fid, OP_AT_LEAST_K);
 }
 
 bool pb_util::is_at_least_k(app *a, rational& k) const {
@@ -152,8 +152,8 @@ bool pb_util::is_at_least_k(app *a, rational& k) const {
     }
 }
 
-rational pb_util::get_k(app *a) const {
-    parameter const& p = a->get_decl()->get_parameter(0);
+rational pb_util::get_k(func_decl *a) const {
+    parameter const& p = a->get_parameter(0);
     if (is_at_most_k(a) || is_at_least_k(a)) {
         return to_rational(p);
     }
@@ -164,8 +164,8 @@ rational pb_util::get_k(app *a) const {
 }
 
 
-bool pb_util::is_le(app *a) const {
-    return is_app_of(a, m_fid, OP_PB_LE);
+bool pb_util::is_le(func_decl *a) const {
+    return is_decl_of(a, m_fid, OP_PB_LE);
 }
 
 bool pb_util::is_le(app* a, rational& k) const {
@@ -178,8 +178,8 @@ bool pb_util::is_le(app* a, rational& k) const {
     }
 }
 
-bool pb_util::is_ge(app *a) const {
-    return is_app_of(a, m_fid, OP_PB_GE);
+bool pb_util::is_ge(func_decl *a) const {
+    return is_decl_of(a, m_fid, OP_PB_GE);
 }
 
 bool pb_util::is_ge(app* a, rational& k) const {
@@ -192,13 +192,13 @@ bool pb_util::is_ge(app* a, rational& k) const {
     }
 }
 
-rational pb_util::get_coeff(app* a, unsigned index) {
+rational pb_util::get_coeff(func_decl* a, unsigned index) const {
     if (is_at_most_k(a) || is_at_least_k(a)) {
         return rational::one();
     }
     SASSERT(is_le(a) || is_ge(a));
-    SASSERT(1 + index < a->get_decl()->get_num_parameters());
-    return to_rational(a->get_decl()->get_parameter(index + 1));
+    SASSERT(1 + index < a->get_num_parameters());
+    return to_rational(a->get_parameter(index + 1));
 }
 
 rational pb_util::to_rational(parameter const& p) const {

src/ast/pb_decl_plugin.h

@@ -82,16 +82,22 @@ public:
     app * mk_at_least_k(unsigned num_args, expr * const * args, unsigned k);
     app * mk_le(unsigned num_args, rational const * coeffs, expr * const * args, rational const& k);
     app * mk_ge(unsigned num_args, rational const * coeffs, expr * const * args, rational const& k);
-    bool is_at_most_k(app *a) const;
+    bool is_at_most_k(func_decl *a) const;
+    bool is_at_most_k(app *a) const { return is_at_most_k(a->get_decl()); }
     bool is_at_most_k(app *a, rational& k) const;
-    bool is_at_least_k(app *a) const;
+    bool is_at_least_k(func_decl *a) const;
+    bool is_at_least_k(app *a) const { return is_at_most_k(a->get_decl()); }
     bool is_at_least_k(app *a, rational& k) const;
-    rational get_k(app *a) const;
-    bool is_le(app *a) const;
+    rational get_k(func_decl *a) const;
+    rational get_k(app *a) const { return get_k(a->get_decl()); }
+    bool is_le(func_decl *a) const;
+    bool is_le(app *a) const { return is_le(a->get_decl()); }
     bool is_le(app* a, rational& k) const;
-    bool is_ge(app* a) const;
+    bool is_ge(func_decl* a) const;
+    bool is_ge(app* a) const { return is_ge(a->get_decl()); }
     bool is_ge(app* a, rational& k) const;
-    rational get_coeff(app* a, unsigned index); 
+    rational get_coeff(app* a, unsigned index) const { return get_coeff(a->get_decl(), index); }
+    rational get_coeff(func_decl* a, unsigned index) const; 
 private:
     rational to_rational(parameter const& p) const;
 };

src/ast/rewriter/pb_rewriter.cpp

@@ -0,0 +1,65 @@
+/*++
+Copyright (c) 2013 Microsoft Corporation
+
+Module Name:
+
+    pb_rewriter.cpp
+
+Abstract:
+
+    Basic rewriting rules for PB constraints.
+
+Author:
+
+    Nikolaj Bjorner (nbjorner) 2013-14-12
+
+Notes:
+
+--*/
+
+#include "pb_rewriter.h"
+
+br_status pb_rewriter::mk_app_core(func_decl * f, unsigned num_args, expr * const * args, expr_ref & result) {
+    ast_manager& m = result.get_manager();
+    rational sum(0), maxsum(0);
+    for (unsigned i = 0; i < num_args; ++i) {
+        if (m.is_true(args[i])) {
+            sum += m_util.get_coeff(f, i);
+            maxsum += m_util.get_coeff(f, i);
+        }
+        else if (!m.is_false(args[i])) {
+            maxsum += m_util.get_coeff(f, i);            
+        }
+    }
+    rational k = m_util.get_k(f);
+    
+    switch(f->get_decl_kind()) {
+    case OP_AT_MOST_K:
+    case OP_PB_LE:
+        if (sum > k) {
+            result = m.mk_false();
+            return BR_DONE;
+        }
+        if (maxsum <= k) {
+            result = m.mk_true();
+            return BR_DONE;
+        }
+        return BR_FAILED;
+    case OP_AT_LEAST_K:
+    case OP_PB_GE:
+        if (sum >= k) {
+            result = m.mk_true();
+            return BR_DONE;
+        }
+        if (maxsum < k) {
+            result = m.mk_false();
+            return BR_DONE;
+        }
+        return BR_FAILED;
+    default:
+        UNREACHABLE();
+        return BR_FAILED;
+    }    
+}
+
+

src/ast/rewriter/pb_rewriter.h

@@ -0,0 +1,45 @@
+/*++
+Copyright (c) 2013 Microsoft Corporation
+
+Module Name:
+
+    pb_rewriter.h
+
+Abstract:
+
+    Basic rewriting rules for PB constraints.
+
+Author:
+
+    Nikolaj Bjorner (nbjorner) 2013-14-12
+
+Notes:
+
+--*/
+#ifndef _PB_REWRITER_H_
+#define _PB_REWRITER_H_
+
+#include"pb_decl_plugin.h"
+#include"rewriter_types.h"
+#include"params.h"
+
+/**
+   \brief Cheap rewrite rules for PB constraints
+*/
+class pb_rewriter {
+    pb_util       m_util;
+public:    
+    pb_rewriter(ast_manager & m, params_ref const & p = params_ref()):
+        m_util(m) {
+    }
+    ast_manager & m() const { return m_util.get_manager(); }
+    family_id get_fid() const { return m_util.get_family_id(); }
+
+    void updt_params(params_ref const & p) {}
+    static void get_param_descrs(param_descrs & r) {}
+
+    br_status mk_app_core(func_decl * f, unsigned num_args, expr * const * args, expr_ref & result);
+
+};
+
+#endif

src/ast/rewriter/th_rewriter.cpp

@@ -25,6 +25,7 @@ Notes:
 #include"array_rewriter.h"
 #include"float_rewriter.h"
 #include"dl_rewriter.h"
+#include"pb_rewriter.h"
 #include"rewriter_def.h"
 #include"expr_substitution.h"
 #include"ast_smt2_pp.h"
@@ -41,6 +42,7 @@ struct th_rewriter_cfg : public default_rewriter_cfg {
     datatype_rewriter   m_dt_rw;
     float_rewriter      m_f_rw;
     dl_rewriter         m_dl_rw;
+    pb_rewriter         m_pb_rw;
     arith_util          m_a_util;
     bv_util             m_bv_util;
     unsigned long long  m_max_memory; // in bytes
@@ -195,6 +197,8 @@ struct th_rewriter_cfg : public default_rewriter_cfg {
             return m_f_rw.mk_app_core(f, num, args, result);
         if (fid == m_dl_rw.get_fid())
             return m_dl_rw.mk_app_core(f, num, args, result);
+        if (fid == m_pb_rw.get_fid())
+            return m_pb_rw.mk_app_core(f, num, args, result);
         return BR_FAILED;
     }
 
@@ -644,6 +648,7 @@ struct th_rewriter_cfg : public default_rewriter_cfg {
         m_dt_rw(m),
         m_f_rw(m, p),
         m_dl_rw(m),
+        m_pb_rw(m),
         m_a_util(m),
         m_bv_util(m),
         m_used_dependencies(m),