228 lines
7.2 KiB
C++
228 lines
7.2 KiB
C++
/*
|
|
Copyright (c) 2013-2014 Microsoft Corporation. All rights reserved.
|
|
Released under Apache 2.0 license as described in the file LICENSE.
|
|
|
|
Author: Leonardo de Moura
|
|
*/
|
|
#include <vector>
|
|
#include <memory>
|
|
#include "kernel/replace_fn.h"
|
|
|
|
#ifndef LEAN_DEFAULT_REPLACE_CACHE_CAPACITY
|
|
#define LEAN_DEFAULT_REPLACE_CACHE_CAPACITY 1024*32
|
|
#endif
|
|
|
|
namespace lean {
|
|
struct replace_cache {
|
|
struct entry {
|
|
expr_cell * m_cell;
|
|
unsigned m_offset;
|
|
expr m_result;
|
|
entry():m_cell(nullptr) {}
|
|
};
|
|
unsigned m_capacity;
|
|
std::vector<entry> m_cache;
|
|
std::vector<unsigned> m_used;
|
|
replace_cache(unsigned c):m_capacity(c), m_cache(c) {}
|
|
|
|
expr * find(expr const & e, unsigned offset) {
|
|
unsigned i = hash(e.hash_alloc(), offset) % m_capacity;
|
|
if (m_cache[i].m_cell == e.raw())
|
|
return &m_cache[i].m_result;
|
|
else
|
|
return nullptr;
|
|
}
|
|
|
|
void insert(expr const & e, unsigned offset, expr const & v) {
|
|
unsigned i = hash(e.hash_alloc(), offset) % m_capacity;
|
|
if (m_cache[i].m_cell == nullptr)
|
|
m_used.push_back(i);
|
|
m_cache[i].m_cell = e.raw();
|
|
m_cache[i].m_offset = offset;
|
|
m_cache[i].m_result = v;
|
|
}
|
|
|
|
void clear() {
|
|
for (unsigned i : m_used) {
|
|
m_cache[i].m_cell = nullptr;
|
|
m_cache[i].m_result = expr();
|
|
}
|
|
m_used.clear();
|
|
}
|
|
};
|
|
|
|
struct replace_cache_stack {
|
|
unsigned m_top;
|
|
std::vector<std::unique_ptr<replace_cache>> m_cache_stack;
|
|
replace_cache_stack():m_top(0) {}
|
|
};
|
|
|
|
MK_THREAD_LOCAL_GET_DEF(replace_cache_stack, get_replace_cache_stack);
|
|
|
|
class replace_cache_ref {
|
|
replace_cache * m_cache;
|
|
public:
|
|
replace_cache_ref() {
|
|
replace_cache_stack & s = get_replace_cache_stack();
|
|
lean_assert(s.m_top <= s.m_cache_stack.size());
|
|
if (s.m_top == s.m_cache_stack.size())
|
|
s.m_cache_stack.push_back(std::unique_ptr<replace_cache>(new replace_cache(LEAN_DEFAULT_REPLACE_CACHE_CAPACITY)));
|
|
m_cache = s.m_cache_stack[s.m_top].get();
|
|
s.m_top++;
|
|
}
|
|
~replace_cache_ref() {
|
|
replace_cache_stack & s = get_replace_cache_stack();
|
|
lean_assert(s.m_top > 0);
|
|
s.m_top--;
|
|
m_cache->clear();
|
|
}
|
|
replace_cache * operator->() const { return m_cache; }
|
|
};
|
|
|
|
/**
|
|
\brief Functional for applying <tt>F</tt> 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 <tt>F(s, n)</tt>, 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> frame_stack;
|
|
typedef buffer<expr> result_stack;
|
|
|
|
std::function<optional<expr>(expr const &, unsigned)> m_f;
|
|
frame_stack m_fs;
|
|
result_stack m_rs;
|
|
replace_cache_ref m_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 (is_shared(e)) {
|
|
if (auto r = m_cache->find(e, offset)) {
|
|
m_rs.push_back(*r);
|
|
return true;
|
|
}
|
|
shared = true;
|
|
}
|
|
|
|
optional<expr> 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 <tt>f.m_index == idx</tt>.
|
|
When the result is true, <tt>f.m_index</tt> 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<typename F>
|
|
replace_fn(F const & f):m_f(f) {}
|
|
|
|
expr operator()(expr const & e) {
|
|
expr r;
|
|
visit(e, 0);
|
|
while (!m_fs.empty()) {
|
|
begin_loop:
|
|
check_interrupted();
|
|
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;
|
|
}
|
|
};
|
|
|
|
expr replace(expr const & e, std::function<optional<expr>(expr const &, unsigned)> const & f) {
|
|
return replace_fn(f)(e);
|
|
}
|
|
}
|