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intblast with lazy expansion of shl, ashr, lshr

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2023-12-16 15:12:57 -08:00
parent 50e0fd3ba6
commit d0a59f3740
10 changed files with 321 additions and 83 deletions
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75
src/sat/smt/intblast_solver.cpp
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@ -656,24 +656,58 @@ namespace intblast {
break;
}
case OP_BSHL: {
expr* x = arg(0), * y = umod(e, 1);
r = a.mk_int(0);
for (unsigned i = 0; i < bv.get_bv_size(e); ++i)
r = m.mk_ite(m.mk_eq(y, a.mk_int(i)), a.mk_mul(x, a.mk_int(rational::power_of_two(i))), r);
if (!a.is_numeral(arg(0)) && !a.is_numeral(arg(1)))
r = a.mk_shl(bv.get_bv_size(e), arg(0),arg(1));
else {
expr* x = arg(0), * y = umod(e, 1);
r = a.mk_int(0);
IF_VERBOSE(2, verbose_stream() << "shl " << mk_bounded_pp(e, m) << " " << bv.get_bv_size(e) << "\n");
for (unsigned i = 0; i < bv.get_bv_size(e); ++i)
r = m.mk_ite(m.mk_eq(y, a.mk_int(i)), a.mk_mul(x, a.mk_int(rational::power_of_two(i))), r);
}
break;
}
case OP_BNOT:
r = bnot(arg(0));
break;
case OP_BLSHR: {
expr* x = arg(0), * y = umod(e, 1);
r = a.mk_int(0);
for (unsigned i = 0; i < bv.get_bv_size(e); ++i)
r = m.mk_ite(m.mk_eq(y, a.mk_int(i)), a.mk_idiv(x, a.mk_int(rational::power_of_two(i))), r);
case OP_BLSHR:
if (!a.is_numeral(arg(0)) && !a.is_numeral(arg(1)))
r = a.mk_lshr(bv.get_bv_size(e), arg(0), arg(1));
else {
expr* x = arg(0), * y = umod(e, 1);
r = a.mk_int(0);
IF_VERBOSE(2, verbose_stream() << "lshr " << mk_bounded_pp(e, m) << " " << bv.get_bv_size(e) << "\n");
for (unsigned i = 0; i < bv.get_bv_size(e); ++i)
r = m.mk_ite(m.mk_eq(y, a.mk_int(i)), a.mk_idiv(x, a.mk_int(rational::power_of_two(i))), r);
}
break;
case OP_BASHR:
if (!a.is_numeral(arg(1)))
r = a.mk_ashr(bv.get_bv_size(e), arg(0), arg(1));
else {
//
// ashr(x, y)
// if y = k & x >= 0 -> x / 2^k
// if y = k & x < 0 -> (x / 2^k) - 2^{N-k}
//
unsigned sz = bv.get_bv_size(e);
rational N = bv_size(e);
expr* x = umod(e, 0), *y = umod(e, 1);
expr* signx = a.mk_ge(x, a.mk_int(N / 2));
r = m.mk_ite(signx, a.mk_int(- 1), a.mk_int(0));
IF_VERBOSE(1, verbose_stream() << "ashr " << mk_bounded_pp(e, m) << " " << bv.get_bv_size(e) << "\n");
for (unsigned i = 0; i < sz; ++i) {
expr* d = a.mk_idiv(x, a.mk_int(rational::power_of_two(i)));
r = m.mk_ite(m.mk_eq(y, a.mk_int(i)),
m.mk_ite(signx, a.mk_add(d, a.mk_int(- rational::power_of_two(sz-i))), d),
r);
}
}
break;
}
case OP_BOR: {
// p | q := (p + q) - band(p, q)
IF_VERBOSE(2, verbose_stream() << "bor " << mk_bounded_pp(e, m) << " " << bv.get_bv_size(e) << "\n");
r = arg(0);
for (unsigned i = 1; i < args.size(); ++i)
r = a.mk_sub(a.mk_add(r, arg(i)), a.mk_band(bv.get_bv_size(e), r, arg(i)));
@ -683,12 +717,14 @@ namespace intblast {
r = bnot(band(args));
break;
case OP_BAND:
IF_VERBOSE(2, verbose_stream() << "band " << mk_bounded_pp(e, m) << " " << bv.get_bv_size(e) << "\n");
r = band(args);
break;
case OP_BXNOR:
case OP_BXOR: {
// p ^ q := (p + q) - 2*band(p, q);
unsigned sz = bv.get_bv_size(e);
IF_VERBOSE(2, verbose_stream() << "bxor " << bv.get_bv_size(e) << "\n");
r = arg(0);
for (unsigned i = 1; i < args.size(); ++i) {
expr* q = arg(i);
@ -698,25 +734,6 @@ namespace intblast {
r = bnot(r);
break;
}
case OP_BASHR: {
//
// ashr(x, y)
// if y = k & x >= 0 -> x / 2^k
// if y = k & x < 0 -> (x / 2^k) - 1 + 2^{N-k}
//
unsigned sz = bv.get_bv_size(e);
rational N = bv_size(e);
expr* x = umod(e, 0), *y = umod(e, 1);
expr* signx = a.mk_ge(x, a.mk_int(N / 2));
r = m.mk_ite(signx, a.mk_int(- 1), a.mk_int(0));
for (unsigned i = 0; i < sz; ++i) {
expr* d = a.mk_idiv(x, a.mk_int(rational::power_of_two(i)));
r = m.mk_ite(m.mk_eq(y, a.mk_int(i)),
m.mk_ite(signx, a.mk_add(d, a.mk_int(- rational::power_of_two(sz-i))), d),
r);
}
break;
}
case OP_ZERO_EXT:
bv_expr = e->get_arg(0);
r = umod(bv_expr, 0);