From 026622a790afbc29e3246fdcedaf457245d7debe Mon Sep 17 00:00:00 2001 From: Leonardo de Moura Date: Thu, 12 Mar 2015 16:22:49 -0700 Subject: [PATCH] refactor(src/kernel/replace_fn): remove stack-less replace_fn it is slower than the simple one --- src/kernel/replace_fn.cpp | 150 +------------------------------------- 1 file changed, 1 insertion(+), 149 deletions(-) diff --git a/src/kernel/replace_fn.cpp b/src/kernel/replace_fn.cpp index 4f9fd265e..3c29845e3 100644 --- a/src/kernel/replace_fn.cpp +++ b/src/kernel/replace_fn.cpp @@ -58,151 +58,6 @@ struct replace_cache { MK_CACHE_STACK(replace_cache, LEAN_DEFAULT_REPLACE_CACHE_CAPACITY) -/** - \brief Functional for applying F to the subexpressions of a given expression. - - The signature of \c F is - expr const &, unsigned -> optional(expr) - - F is invoked for each subexpression \c s of the input expression e. - In a call F(s, n), n is the scope level, i.e., the number of - bindings operators that enclosing \c s. The replaces only visits children of \c e - if F return none_expr -*/ -class replace_fn { - struct frame { - expr m_expr; - unsigned m_offset; - bool m_shared; - unsigned m_index; - frame(expr const & e, unsigned o, bool s):m_expr(e), m_offset(o), m_shared(s), m_index(0) {} - }; - typedef buffer frame_stack; - typedef buffer result_stack; - - std::function(expr const &, unsigned)> m_f; - frame_stack m_fs; - result_stack m_rs; - replace_cache_ref m_cache; - bool m_use_cache; - - void save_result(expr const & e, expr const & r, unsigned offset, bool shared) { - if (shared) - m_cache->insert(e, offset, r); - m_rs.push_back(r); - } - - /** - \brief Visit \c e at the given offset. Return true iff the result is on the - result stack \c m_rs. Return false iff a new frame was pushed on the stack \c m_fs. - The idea is that after the frame is processed, the result will be on the result stack. - */ - bool visit(expr const & e, unsigned offset) { - bool shared = false; - if (m_use_cache && is_shared(e)) { - if (auto r = m_cache->find(e, offset)) { - m_rs.push_back(*r); - return true; - } - shared = true; - } - - optional r = m_f(e, offset); - if (r) { - save_result(e, *r, offset, shared); - return true; - } else if (is_atomic(e)) { - save_result(e, e, offset, shared); - return true; - } else { - m_fs.emplace_back(e, offset, shared); - return false; - } - } - - /** - \brief Return true iff f.m_index == idx. - When the result is true, f.m_index is incremented. - */ - bool check_index(frame & f, unsigned idx) { - if (f.m_index == idx) { - f.m_index++; - return true; - } else { - return false; - } - } - - expr const & rs(int i) { - lean_assert(i < 0); - return m_rs[m_rs.size() + i]; - } - - void pop_rs(unsigned num) { - m_rs.shrink(m_rs.size() - num); - } - -public: - template - replace_fn(F const & f, bool use_cache):m_f(f), m_use_cache(use_cache) {} - - expr operator()(expr const & e) { - expr r; - visit(e, 0); - while (!m_fs.empty()) { - begin_loop: - check_interrupted(); - check_memory("replace"); - frame & f = m_fs.back(); - expr const & e = f.m_expr; - unsigned offset = f.m_offset; - switch (e.kind()) { - case expr_kind::Constant: case expr_kind::Sort: - case expr_kind::Var: - lean_unreachable(); // LCOV_EXCL_LINE - case expr_kind::Meta: case expr_kind::Local: - if (check_index(f, 0) && !visit(mlocal_type(e), offset)) - goto begin_loop; - r = update_mlocal(e, rs(-1)); - pop_rs(1); - break; - case expr_kind::App: - if (check_index(f, 0) && !visit(app_fn(e), offset)) - goto begin_loop; - if (check_index(f, 1) && !visit(app_arg(e), offset)) - goto begin_loop; - r = update_app(e, rs(-2), rs(-1)); - pop_rs(2); - break; - case expr_kind::Pi: case expr_kind::Lambda: - if (check_index(f, 0) && !visit(binding_domain(e), offset)) - goto begin_loop; - if (check_index(f, 1) && !visit(binding_body(e), offset + 1)) - goto begin_loop; - r = update_binding(e, rs(-2), rs(-1)); - pop_rs(2); - break; - case expr_kind::Macro: - while (f.m_index < macro_num_args(e)) { - unsigned idx = f.m_index; - f.m_index++; - if (!visit(macro_arg(e, idx), offset)) - goto begin_loop; - } - r = update_macro(e, macro_num_args(e), &rs(-macro_num_args(e))); - pop_rs(macro_num_args(e)); - break; - } - save_result(e, r, offset, f.m_shared); - m_fs.pop_back(); - } - lean_assert(m_rs.size() == 1); - r = m_rs.back(); - m_rs.pop_back(); - return r; - } -}; - class replace_rec_fn { replace_cache_ref m_cache; std::function(expr const &, unsigned)> m_f; @@ -262,9 +117,6 @@ public: }; expr replace(expr const & e, std::function(expr const &, unsigned)> const & f, bool use_cache) { - if (get_weight(e) < LEAN_REPLACE_SMALL_TERM_THRESHOLD) - return replace_rec_fn(f, use_cache)(e); - else - return replace_fn(f, use_cache)(e); + return replace_rec_fn(f, use_cache)(e); } }