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add rewriting option to simplify store equalities

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2013-05-13 11:43:30 -07:00
parent 5eed106ffe
commit e35fd58968
5 changed files with 47 additions and 1 deletions

View file

@ -25,6 +25,7 @@ void array_rewriter::updt_params(params_ref const & _p) {
array_rewriter_params p(_p);
m_sort_store = p.sort_store();
m_expand_select_store = p.expand_select_store();
m_expand_store_eq = p.expand_store_eq();
}
void array_rewriter::get_param_descrs(param_descrs & r) {
@ -365,3 +366,40 @@ br_status array_rewriter::mk_set_subset(expr * arg1, expr * arg2, expr_ref & res
return BR_REWRITE3;
}
br_status array_rewriter::mk_eq_core(expr * lhs, expr * rhs, expr_ref & result) {
if (!m_expand_store_eq) {
return BR_FAILED;
}
expr* lhs1 = lhs;
while (m_util.is_store(lhs1)) {
lhs1 = to_app(lhs1)->get_arg(0);
}
expr* rhs1 = rhs;
while (m_util.is_store(rhs1)) {
rhs1 = to_app(rhs1)->get_arg(0);
}
if (lhs1 != rhs1) {
return BR_FAILED;
}
ptr_buffer<expr> fmls, args;
expr* e;
expr_ref tmp1(m()), tmp2(m());
#define MK_EQ() \
while (m_util.is_store(e)) { \
args.push_back(lhs); \
args.append(to_app(e)->get_num_args()-2,to_app(e)->get_args()+1); \
mk_select(args.size(), args.c_ptr(), tmp1); \
args[0] = rhs; \
mk_select(args.size(), args.c_ptr(), tmp2); \
fmls.push_back(m().mk_eq(tmp1, tmp2)); \
e = to_app(e)->get_arg(0); \
args.reset(); \
} \
e = lhs;
MK_EQ();
e = rhs;
MK_EQ();
result = m().mk_and(fmls.size(), fmls.c_ptr());
return BR_REWRITE_FULL;
}

View file

@ -31,12 +31,14 @@ class array_rewriter {
array_util m_util;
bool m_sort_store;
bool m_expand_select_store;
bool m_expand_store_eq;
template<bool CHECK_DISEQ>
lbool compare_args(unsigned num_args, expr * const * args1, expr * const * args2);
public:
array_rewriter(ast_manager & m, params_ref const & p = params_ref()):
m_util(m) {
updt_params(p);
}
ast_manager & m() const { return m_util.get_manager(); }
family_id get_fid() const { return m_util.get_family_id(); }
@ -60,6 +62,7 @@ public:
br_status mk_set_complement(expr * arg, expr_ref & result);
br_status mk_set_difference(expr * arg1, expr * arg2, expr_ref & result);
br_status mk_set_subset(expr * arg1, expr * arg2, expr_ref & result);
br_status mk_eq_core(expr * lhs, expr * rhs, expr_ref & result);
};
#endif

View file

@ -2,4 +2,5 @@ def_module_params(module_name='rewriter',
class_name='array_rewriter_params',
export=True,
params=(("expand_select_store", BOOL, False, "replace a (select (store ...) ...) term by an if-then-else term"),
("expand_store_eq", BOOL, False, "reduce (store ...) = (store ...) with a common base into selects"),
("sort_store", BOOL, False, "sort nested stores when the indices are known to be different")))

View file

@ -62,6 +62,8 @@ struct mk_simplified_app::imp {
st = m_dt_rw.mk_eq_core(args[0], args[1], result);
else if (s_fid == m_f_rw.get_fid())
st = m_f_rw.mk_eq_core(args[0], args[1], result);
else if (s_fid == m_ar_rw.get_fid())
st = m_ar_rw.mk_eq_core(args[0], args[1], result);
if (st != BR_FAILED)
return st;

View file

@ -169,7 +169,9 @@ struct th_rewriter_cfg : public default_rewriter_cfg {
st = m_dt_rw.mk_eq_core(args[0], args[1], result);
else if (s_fid == m_f_rw.get_fid())
st = m_f_rw.mk_eq_core(args[0], args[1], result);
else if (s_fid == m_ar_rw.get_fid())
st = m_ar_rw.mk_eq_core(args[0], args[1], result);
if (st != BR_FAILED)
return st;
}