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fix bug in conflict clause generation in seq-branch-variable

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2016-02-26 18:15:45 -08:00
parent 4c408165ab
commit ce8862d415
11 changed files with 344 additions and 87 deletions
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40
src/ast/rewriter/seq_rewriter.cpp
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@ -437,7 +437,12 @@ br_status seq_rewriter::mk_seq_contains(expr* a, expr* b, expr_ref& result) {
m_util.str.get_concat(a, as);
m_util.str.get_concat(b, bs);
bool all_values = true;
if (bs.empty()) {
result = m().mk_true();
return BR_DONE;
}
for (unsigned i = 0; all_values && i < bs.size(); ++i) {
all_values = m().is_value(bs[i].get());
}
@ -459,6 +464,39 @@ br_status seq_rewriter::mk_seq_contains(expr* a, expr* b, expr_ref& result) {
result = m().mk_false();
return BR_DONE;
}
unsigned lenA = 0, lenB = 0;
bool lA = min_length(as.size(), as.c_ptr(), lenA);
if (lA) {
bool lB = min_length(bs.size(), bs.c_ptr(), lenB);
if (lenB > lenA) {
result = m().mk_false();
return BR_DONE;
}
}
if (as.empty()) {
result = m().mk_eq(b, m_util.str.mk_empty(m().get_sort(b)));
return BR_REWRITE2;
}
unsigned offs = 0;
unsigned sz = as.size();
expr* b0 = bs[0].get();
expr* bL = bs[bs.size()-1].get();
for (; offs < as.size() && m().are_distinct(b0, as[offs].get()); ++offs) {};
for (; sz > offs && m().are_distinct(bL, as[sz-1].get()); --sz) {}
if (offs == sz) {
result = m().mk_eq(b, m_util.str.mk_empty(m().get_sort(b)));
return BR_REWRITE2;
}
if (offs > 0 || sz < as.size()) {
SASSERT(sz > offs);
result = m_util.str.mk_contains(m_util.str.mk_concat(sz-offs, as.c_ptr()+offs), b);
return BR_REWRITE2;
}
return BR_FAILED;
}