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add rewrite rules to bv-rewriter

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This commit is contained in:
Nikolaj Bjorner 2022-11-08 12:20:51 -08:00
parent a34701471f
commit 3a4b8e2334
1 changed files with 35 additions and 9 deletions
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44
src/ast/rewriter/bv_rewriter.cpp
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@ -1513,11 +1513,14 @@ br_status bv_rewriter::mk_concat(unsigned num_args, expr * const * args, expr_re
bool fused_numeral = false; bool fused_numeral = false;
bool expanded = false; bool expanded = false;
bool fused_extract = false; bool fused_extract = false;
bool eq_args = true;
for (unsigned i = 0; i < num_args; i++) { for (unsigned i = 0; i < num_args; i++) {
expr * arg = args[i]; expr * arg = args[i];
expr * prev = nullptr; expr * prev = nullptr;
if (i > 0) if (i > 0) {
prev = new_args.back(); prev = new_args.back();
eq_args &= prev == arg;
}
if (is_numeral(arg, v1, sz1) && prev != nullptr && is_numeral(prev, v2, sz2)) { if (is_numeral(arg, v1, sz1) && prev != nullptr && is_numeral(prev, v2, sz2)) {
v2 *= rational::power_of_two(sz1); v2 *= rational::power_of_two(sz1);
v2 += v1; v2 += v1;
@ -1526,10 +1529,8 @@ br_status bv_rewriter::mk_concat(unsigned num_args, expr * const * args, expr_re
fused_numeral = true; fused_numeral = true;
} }
else if (m_flat && m_util.is_concat(arg)) { else if (m_flat && m_util.is_concat(arg)) {
unsigned num2 = to_app(arg)->get_num_args(); for (expr* arg2 : *to_app(arg))
for (unsigned j = 0; j < num2; j++) { new_args.push_back(arg2);
new_args.push_back(to_app(arg)->get_arg(j));
}
expanded = true; expanded = true;
} }
else if (m_util.is_extract(arg) && else if (m_util.is_extract(arg) &&
@ -1539,8 +1540,8 @@ br_status bv_rewriter::mk_concat(unsigned num_args, expr * const * args, expr_re
m_util.get_extract_low(prev) == m_util.get_extract_high(arg) + 1) { m_util.get_extract_low(prev) == m_util.get_extract_high(arg) + 1) {
// (concat (extract[h1,l1] a) (extract[h2,l2] a)) --> (extract[h1,l2] a) if l1 == h2+1 // (concat (extract[h1,l1] a) (extract[h2,l2] a)) --> (extract[h1,l2] a) if l1 == h2+1
expr * new_arg = m_mk_extract(m_util.get_extract_high(prev), expr * new_arg = m_mk_extract(m_util.get_extract_high(prev),
m_util.get_extract_low(arg), m_util.get_extract_low(arg),
to_app(arg)->get_arg(0)); to_app(arg)->get_arg(0));
new_args.pop_back(); new_args.pop_back();
new_args.push_back(new_arg); new_args.push_back(new_arg);
fused_extract = true; fused_extract = true;
@ -1549,14 +1550,26 @@ br_status bv_rewriter::mk_concat(unsigned num_args, expr * const * args, expr_re
new_args.push_back(arg); new_args.push_back(arg);
} }
} }
if (!fused_numeral && !expanded && !fused_extract) if (!fused_numeral && !expanded && !fused_extract) {
expr* x, *y, *z;
if (eq_args) {
if (m().is_ite(new_args.back(), x, y, z)) {
ptr_buffer<expr> args1, args2;
for (expr* arg : new_args)
args1.push_back(y), args2.push_back(z);
result = m().mk_ite(x, m_util.mk_concat(args1), m_util.mk_concat(args2));
return BR_REWRITE2;
}
}
return BR_FAILED; return BR_FAILED;
}
SASSERT(!new_args.empty()); SASSERT(!new_args.empty());
if (new_args.size() == 1) { if (new_args.size() == 1) {
result = new_args.back(); result = new_args.back();
return fused_extract ? BR_REWRITE1 : BR_DONE; return fused_extract ? BR_REWRITE1 : BR_DONE;
} }
result = m_util.mk_concat(new_args.size(), new_args.data()); result = m_util.mk_concat(new_args);
if (fused_extract) if (fused_extract)
return BR_REWRITE2; return BR_REWRITE2;
else if (expanded) else if (expanded)
@ -2013,6 +2026,19 @@ br_status bv_rewriter::mk_bv_not(expr * arg, expr_ref & result) {
return BR_REWRITE2; return BR_REWRITE2;
} }
expr* x, *y, *z;
if (m().is_ite(arg, x, y, z) && m_util.is_numeral(y, val, bv_size)) {
val = bitwise_not(bv_size, val);
result = m().mk_ite(x, m_util.mk_numeral(val, bv_size), m_util.mk_bv_not(z));
return BR_REWRITE2;
}
if (m().is_ite(arg, x, y, z) && m_util.is_numeral(z, val, bv_size)) {
val = bitwise_not(bv_size, val);
result = m().mk_ite(x, m_util.mk_bv_not(y), m_util.mk_numeral(val, bv_size));
return BR_REWRITE2;
}
if (m_bvnot_simpl) { if (m_bvnot_simpl) {
expr *s(nullptr), *t(nullptr); expr *s(nullptr), *t(nullptr);
if (m_util.is_bv_mul(arg, s, t)) { if (m_util.is_bv_mul(arg, s, t)) {