add incremental version of value propagate

src/ast/simplifiers/propagate_values.h

@@ -0,0 +1,45 @@
+/*++
+Copyright (c) 2022 Microsoft Corporation
+
+Module Name:
+
+    propagate_values.h
+
+Abstract:
+
+    relatively cheap value propagation
+
+Author:
+
+    Nikolaj Bjorner (nbjorner) 2022-11-24
+
+Notes:
+    incremental version of propagate_values_tactic, to be replaced
+
+--*/
+
+#pragma once
+
+#include "ast/simplifiers/dependent_expr_state.h"
+#include "ast/rewriter/th_rewriter.h"
+
+
+class propagate_values : public dependent_expr_simplifier {
+
+    struct stats {
+        unsigned m_num_rewrites = 0;
+        void reset() { memset(this, 0, sizeof(*this)); }
+    };
+
+    th_rewriter            m_rewriter;
+    stats                  m_stats;
+    unsigned               m_max_rounds = 4;
+
+public:
+    propagate_values(ast_manager& m, dependent_expr_state& fmls);
+    void reduce() override;
+    void collect_statistics(statistics& st) const override;
+    void reset_statistics() override { m_stats.reset(); }
+    void updt_params(params_ref const& p) override;
+    void collect_param_descrs(param_descrs& r) override;
+};