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make the two monotonicity tests into one using push/pop; fix division modelling (#5220)

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* make the two monotonicity tests into one using push/pop

* whitespace...

* proper division modelling for monotonicity test -- overflow checks still missing, though

* double bitwidth for overflow checking in monotonicity example
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alexandernutz 2021-05-20 19:00:13 +02:00 • committed by GitHub
parent 973a32a015
commit 8a5addd891
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1 changed files with 41 additions and 60 deletions
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101
src/test/polysat.cpp
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@ -346,108 +346,89 @@ namespace polysat {
/**
* Monotonicity example from certora (1)
* expected: unsat
* Monotonicity example from certora
*/
static void test_monot1() {
static void test_monot() {
scoped_solver s(__func__);
auto bw = 5;
auto baseBw = 5;
auto max_int_const = 31; // (2^5 - 1) -- change this if you change baseBw
auto bw = 2 * baseBw;
auto max_int = s.var(s.add_var(bw));
s.add_eq(max_int - max_int_const);
auto tb1 = s.var(s.add_var(bw));
s.add_ule(tb1, max_int);
auto tb2 = s.var(s.add_var(bw));
s.add_ule(tb2, max_int);
auto a = s.var(s.add_var(bw));
s.add_ule(a, max_int);
auto v = s.var(s.add_var(bw));
s.add_ule(v, max_int);
auto base1 = s.var(s.add_var(bw));
s.add_ule(base1, max_int);
auto base2 = s.var(s.add_var(bw));
s.add_ule(base2, max_int);
auto elastic1 = s.var(s.add_var(bw));
s.add_ule(elastic1, max_int);
auto elastic2 = s.var(s.add_var(bw));
s.add_ule(elastic2, max_int);
auto err = s.var(s.add_var(bw));
s.add_ule(err, max_int);
auto zero = a - a;
auto rem1 = s.var(s.add_var(bw));
auto quot2 = s.var(s.add_var(bw));
s.add_ule(quot2, max_int);
auto rem2 = s.var(s.add_var(bw));
auto rem3 = s.var(s.add_var(bw));
auto quot4 = s.var(s.add_var(bw));
s.add_ule(quot4, max_int);
auto rem4 = s.var(s.add_var(bw));
s.add_diseq(elastic1);
// tb1 = (v * base1) / elastic1;
// division: tb1 = (v * base1) / elastic1;
s.add_eq((tb1 * elastic1) + rem1 - (v * base1));
s.add_ult(rem1, elastic1);
s.add_ule((tb1 * elastic1), max_int);
// quot2 = (a * base1) / elastic1
// division: quot2 = (a * base1) / elastic1
s.add_eq((quot2 * elastic1) + rem2 - (a * base1));
s.add_ult(rem2, elastic1);
s.add_ule((quot2 * elastic1), max_int);
s.add_eq(base1 + quot2 - base2);
s.add_eq(elastic1 + a - elastic2);
// tb2 = ((v * base2) / elastic2);
// division: tb2 = ((v * base2) / elastic2);
s.add_eq((tb2 * elastic2) + rem3 - (v * base2));
s.add_ult(rem3, elastic2);
s.add_ule((tb2 * elastic2), max_int);
// quot4 = v / (elastic1 + a);
s.add_eq((quot4 * (elastic1 + a)) + rem4 - v);
// division: quot4 = v / elastic2;
s.add_eq((quot4 * elastic2) + rem4 - v);
s.add_ult(rem4, elastic2);
s.add_ule((quot4 * elastic2), max_int);
s.add_eq(quot4 + 1 - err);
s.push();
s.add_ult(tb1, tb2);
s.check();
s.expect_unsat();
}
s.pop();
/**
* Monotonicity example from certora (2)
* expected: unsat
*
* only difference to (1) is the inequality right before the check
*/
static void test_monot2() {
scoped_solver s(__func__);
auto bw = 5;
auto tb1 = s.var(s.add_var(bw));
auto tb2 = s.var(s.add_var(bw));
auto a = s.var(s.add_var(bw));
auto v = s.var(s.add_var(bw));
auto base1 = s.var(s.add_var(bw));
auto base2 = s.var(s.add_var(bw));
auto elastic1 = s.var(s.add_var(bw));
auto elastic2 = s.var(s.add_var(bw));
auto err = s.var(s.add_var(bw));
auto rem1 = s.var(s.add_var(bw));
auto quot2 = s.var(s.add_var(bw));
auto rem2 = s.var(s.add_var(bw));
auto rem3 = s.var(s.add_var(bw));
auto quot4 = s.var(s.add_var(bw));
auto rem4 = s.var(s.add_var(bw));
s.add_diseq(elastic1);
// tb1 = (v * base1) / elastic1;
s.add_eq((tb1 * elastic1) + rem1 - (v * base1));
// quot2 = (a * base1) / elastic1
s.add_eq((quot2 * elastic1) + rem2 - (a * base1));
s.add_eq(base1 + quot2 - base2);
s.add_eq(elastic1 + a - elastic2);
// tb2 = ((v * base2) / elastic2);
s.add_eq((tb2 * elastic2) + rem3 - (v * base2));
// quot4 = v / (elastic1 + a);
s.add_eq((quot4 * (elastic1 + a)) + rem4 - v);
s.add_eq(quot4 + 1 - err);
s.add_ult(tb1 + err, tb2);
s.push();
s.add_ult(tb2 + err, tb1);
s.check();
s.expect_unsat();
s.pop();
}
// Goal: we probably mix up polysat variables and PDD variables at several points; try to uncover such cases
// NOTE: actually, add_var seems to keep them in sync, so this is not an issue at the moment (but we should still test it later)
// static void test_mixed_vars() {