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fix subtraction

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2019-12-27 15:49:54 -08:00
parent dd07d21f6c
commit 1e99059a5d
3 changed files with 37 additions and 33 deletions
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30
src/math/dd/dd_pdd.cpp
View file

@ -171,32 +171,24 @@ namespace dd {
}
break;
case pdd_sub_op:
if (is_val(p)) {
if (is_val(p) || (!is_val(q) && level_p < level_q)) {
// p - (ax + b) = -ax + (p - b)
push(apply_rec(p, lo(q), op));
r = make_node(level_q, read(1), hi(q));
npop = 1;
push(minus_rec(hi(q)));
r = make_node(level_q, read(2), read(1));
}
else if (is_val(q)) {
push(apply_rec(lo(p), q, op));
r = make_node(level_p, read(1), hi(p));
npop = 1;
}
else if (level_p == level_q) {
push(apply_rec(lo(p), lo(q), op));
push(apply_rec(hi(p), hi(q), op));
r = make_node(level_p, read(2), read(1));
}
else if (level_p > level_q) {
// x*hi(p) + (lo(p) - q)
else if (is_val(q) || (level_p > level_q)) {
// (ax + b) - k = ax + (b - k)
push(apply_rec(lo(p), q, op));
r = make_node(level_p, read(1), hi(p));
npop = 1;
}
else {
// x*hi(q) + (p - lo(q))
push(apply_rec(p, lo(q), op));
r = make_node(level_q, read(1), hi(q));
npop = 1;
SASSERT(level_p == level_q);
// (ax + b) - (cx + d) = (a - c)x + (b - d)
push(apply_rec(lo(p), lo(q), op));
push(apply_rec(hi(p), hi(q), op));
r = make_node(level_p, read(2), read(1));
}
break;
case pdd_mul_op:

22
src/math/grobner/pdd_grobner.cpp
View file

@ -12,6 +12,7 @@
--*/
#include "math/grobner/pdd_grobner.h"
#include "util/uint_set.h"
namespace dd {
@ -125,6 +126,7 @@ namespace dd {
}
void grobner::saturate() {
simplify();
if (is_tuned()) tuned_init();
try {
while (!done() && step()) {
@ -214,7 +216,10 @@ namespace dd {
equation_vector linear;
for (equation* e : m_to_simplify) {
pdd p = e->poly();
if (p.is_linear() && (!binary || p.is_binary())) {
if (binary) {
if (p.is_binary()) linear.push_back(e);
}
else if (p.is_linear()) {
linear.push_back(e);
}
}
@ -798,10 +803,17 @@ namespace dd {
}
i = 0;
uint_set head_vars;
for (auto* e : m_solved) {
VERIFY(e->state() == solved);
VERIFY(e->idx() == i);
++i;
pdd p = e->poly();
if (!p.is_val() && p.hi().is_val()) {
unsigned v = p.var();
SASSERT(!head_vars.contains(v));
head_vars.insert(v);
}
}
// equations in to_simplify have correct indices
@ -811,11 +823,9 @@ namespace dd {
for (auto* e : m_to_simplify) {
VERIFY(e->idx() == i);
VERIFY(e->state() == to_simplify);
VERIFY(!e->poly().is_val());
if (is_tuned()) {
pdd const& p = e->poly();
VERIFY(p.is_val() || m_watch[p.var()].contains(e));
}
pdd const& p = e->poly();
VERIFY(!p.is_val());
VERIFY(!is_tuned() || m_watch[p.var()].contains(e));
++i;
}
// the watch list consists of equations in to_simplify

18
src/test/pdd_grobner.cpp
View file

@ -28,21 +28,23 @@ namespace dd {
grobner gb(lim, m);
gb.add(v1*v2 + v1*v3);
gb.add(v1 - 1);
print_eqs(gb.equations());
gb.display(std::cout);
gb.saturate();
print_eqs(gb.equations());
gb.display(std::cout);
gb.reset();
gb.add(v1*v1*v2 + v2*v3);
gb.add(v1*v1*v2 + v2*v1);
gb.display(std::cout);
gb.saturate();
print_eqs(gb.equations());
gb.display(std::cout);
gb.reset();
gb.add(v1*v1*v2 + v2*v1);
gb.add(v1*v1*v2 + v2*v1);
gb.display(std::cout);
gb.saturate();
print_eqs(gb.equations());
gb.display(std::cout);
gb.reset();
// stop early on contradiction
@ -52,7 +54,7 @@ namespace dd {
gb.add(v3*v1 + v1*v2 + v2*v3 + v1);
gb.add(v3*v1 + v1*v2 + v2*v3 + v2);
gb.saturate();
print_eqs(gb.equations());
gb.display(std::cout << "early contradiction\n");
gb.reset();
// result is v1 = 0, v2 = 0.
@ -61,15 +63,15 @@ namespace dd {
gb.add(v3*v1 + v1*v2 + v2*v3 + v1);
gb.add(v3*v1 + v1*v2 + v2*v3 + v2);
gb.saturate();
print_eqs(gb.equations());
gb.display(std::cout << "v1 = v2 = 0\n");
gb.reset();
// everything rewrites to a multiple of v0
gb.add(v3 - 2*v2);
gb.add(v2 - 2*v1);
gb.add(v1 - 2*v0);
gb.saturate();
print_eqs(gb.equations());
gb.saturate();
gb.display(std::cout << "multiple of v0\n");
gb.reset();
//