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fix : incorrect bvurem rewrite when divisor=0

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also, always enable this rewrite, since it shrinks formula size globally
This commit is contained in:
Nuno Lopes 2020-04-22 15:26:30 +01:00
parent dd064a5554
commit 220bc7fcd9
2 changed files with 3 additions and 5 deletions

5
src/ast/rewriter/bv_rewriter.cpp
View file

@ -29,7 +29,6 @@ void bv_rewriter::updt_local_params(params_ref const & _p) {
m_elim_sign_ext = p.elim_sign_ext();
m_mul2concat = p.mul2concat();
m_bit2bool = p.bit2bool();
m_urem_simpl = p.bv_urem_simpl();
m_blast_eq_value = p.blast_eq_value();
m_split_concat_eq = p.split_concat_eq();
m_bvnot2arith = p.bvnot2arith();
@ -2608,7 +2607,7 @@ br_status bv_rewriter::mk_eq_core(expr * lhs, expr * rhs, expr_ref & result) {
return st;
}
if (m_urem_simpl) {
{
expr * dividend;
expr * divisor;
numeral divisor_val, rhs_val;
@ -2616,7 +2615,7 @@ br_status bv_rewriter::mk_eq_core(expr * lhs, expr * rhs, expr_ref & result) {
if (is_urem_any(lhs, dividend, divisor)
&& is_numeral(rhs, rhs_val, rhs_sz)
&& is_numeral(divisor, divisor_val, divisor_sz)) {
if (rhs_val >= divisor_val) {//(= (bvurem x c1) c2) where c2 >= c1
if (!divisor_val.is_zero() && rhs_val >= divisor_val) {//(= (bvurem x c1) c2) where c2 >= c1
result = m().mk_false();
return BR_DONE;
}

3
src/ast/rewriter/bv_rewriter_params.pyg
View file

@ -12,6 +12,5 @@ def_module_params(module_name='rewriter',
("bv_extract_prop", BOOL, False, "attempt to partially propagate extraction inwards"),
("bv_not_simpl", BOOL, False, "apply simplifications for bvnot"),
("bv_ite2id", BOOL, False, "rewrite ite that can be simplified to identity"),
("bv_le_extra", BOOL, False, "additional bu_(u/s)le simplifications"),
("bv_urem_simpl", BOOL, False, "additional simplification for bvurem")
("bv_le_extra", BOOL, False, "additional bu_(u/s)le simplifications")
))