From ccf36cb7d81a9513db15b8a36c240d2c7ec9f5b5 Mon Sep 17 00:00:00 2001
From: Clifford Wolf <clifford@clifford.at>
Date: Sun, 11 Aug 2013 16:27:15 +0200
Subject: [PATCH] Added SAT support for $div and $mod cells
---
kernel/satgen.h | 46 +++++++++++++++++++++++++++++++++++++++++++++
libs/ezsat/ezsat.cc | 6 ++++++
libs/ezsat/ezsat.h | 3 +++
3 files changed, 55 insertions(+)
diff --git a/kernel/satgen.h b/kernel/satgen.h
index 26e3fd7ec..b2f8b15b7 100644
--- a/kernel/satgen.h
+++ b/kernel/satgen.h
@@ -267,6 +267,52 @@ struct SatGen
return true;
}
+ if (cell->type == "$div" || cell->type == "$mod")
+ {
+ std::vector<int> a = importSigSpec(cell->connections.at("\\A"), timestep);
+ std::vector<int> b = importSigSpec(cell->connections.at("\\B"), timestep);
+ std::vector<int> y = importSigSpec(cell->connections.at("\\Y"), timestep);
+ extendSignalWidth(a, b, y, cell);
+
+ std::vector<int> a_u, b_u;
+ if (cell->parameters["\\A_SIGNED"].as_bool() && cell->parameters["\\B_SIGNED"].as_bool()) {
+ a_u = ez->vec_ite(a.back(), ez->vec_neg(a), a);
+ b_u = ez->vec_ite(b.back(), ez->vec_neg(b), b);
+ } else {
+ a_u = a;
+ b_u = b;
+ }
+
+ std::vector<int> chain_buf = a_u;
+ std::vector<int> y_u(a_u.size(), ez->FALSE);
+ for (int i = int(a.size())-1; i >= 0; i--)
+ {
+ chain_buf.insert(chain_buf.end(), chain_buf.size(), ez->FALSE);
+
+ std::vector<int> b_shl(i, ez->FALSE);
+ b_shl.insert(b_shl.end(), b_u.begin(), b_u.end());
+ b_shl.insert(b_shl.end(), chain_buf.size()-b_shl.size(), ez->FALSE);
+
+ y_u.at(i) = ez->vec_ge_unsigned(chain_buf, b_shl);
+ chain_buf = ez->vec_ite(y_u.at(i), ez->vec_sub(chain_buf, b_shl), chain_buf);
+
+ chain_buf.erase(chain_buf.begin() + a_u.size(), chain_buf.end());
+ }
+
+ if (cell->type == "$div") {
+ if (cell->parameters["\\A_SIGNED"].as_bool() && cell->parameters["\\B_SIGNED"].as_bool())
+ ez->assume(ez->vec_eq(y, ez->vec_ite(ez->XOR(a.back(), b.back()), ez->vec_neg(y_u), y_u)));
+ else
+ ez->assume(ez->vec_eq(y, y_u));
+ } else {
+ if (cell->parameters["\\A_SIGNED"].as_bool() && cell->parameters["\\B_SIGNED"].as_bool())
+ ez->assume(ez->vec_eq(y, ez->vec_ite(a.back(), ez->vec_neg(chain_buf), chain_buf)));
+ else
+ ez->assume(ez->vec_eq(y, chain_buf));
+ }
+ return true;
+ }
+
if (timestep > 0 && (cell->type == "$dff" || cell->type == "$_DFF_N_" || cell->type == "$_DFF_P_")) {
if (timestep == 1) {
initial_state.add((*sigmap)(cell->connections.at("\\Q")));
diff --git a/libs/ezsat/ezsat.cc b/libs/ezsat/ezsat.cc
index 00918f62f..4258fb6fe 100644
--- a/libs/ezsat/ezsat.cc
+++ b/libs/ezsat/ezsat.cc
@@ -852,6 +852,12 @@ std::vector<int> ezSAT::vec_sub(const std::vector<int> &vec1, const std::vector<
return vec;
}
+std::vector<int> ezSAT::vec_neg(const std::vector<int> &vec)
+{
+ std::vector<int> zero(vec.size(), FALSE);
+ return vec_sub(zero, vec);
+}
+
void ezSAT::vec_cmp(const std::vector<int> &vec1, const std::vector<int> &vec2, int &carry, int &overflow, int &sign, int &zero)
{
assert(vec1.size() == vec2.size());
diff --git a/libs/ezsat/ezsat.h b/libs/ezsat/ezsat.h
index 2d0307d51..4a6a72785 100644
--- a/libs/ezsat/ezsat.h
+++ b/libs/ezsat/ezsat.h
@@ -223,6 +223,7 @@ public:
std::vector<int> vec_count(const std::vector<int> &vec, int bits, bool clip = true);
std::vector<int> vec_add(const std::vector<int> &vec1, const std::vector<int> &vec2);
std::vector<int> vec_sub(const std::vector<int> &vec1, const std::vector<int> &vec2);
+ std::vector<int> vec_neg(const std::vector<int> &vec);
void vec_cmp(const std::vector<int> &vec1, const std::vector<int> &vec2, int &carry, int &overflow, int &sign, int &zero);
@@ -305,6 +306,8 @@ struct ezSATvec
ezSATvec(ezSAT &sat, const std::vector<int> &vec) : sat(sat), vec(vec) { }
ezSATvec operator ~() { return ezSATvec(sat, sat.vec_not(vec)); }
+ ezSATvec operator -() { return ezSATvec(sat, sat.vec_neg(vec)); }
+
ezSATvec operator &(const ezSATvec &other) { return ezSATvec(sat, sat.vec_and(vec, other.vec)); }
ezSATvec operator |(const ezSATvec &other) { return ezSATvec(sat, sat.vec_or(vec, other.vec)); }
ezSATvec operator ^(const ezSATvec &other) { return ezSATvec(sat, sat.vec_xor(vec, other.vec)); }