Added ezSAT library

1 files changed, 524 insertions, 0 deletions

diff --git a/libs/ezsat/testbench.cc b/libs/ezsat/testbench.cc
new file mode 100644
index 000000000..cc0fe5734
--- /dev/null
+++ b/libs/ezsat/testbench.cc
@@ -0,0 +1,524 @@
+/*
+ *  ezSAT -- A simple and easy to use CNF generator for SAT solvers
+ *
+ *  Copyright (C) 2013  Clifford Wolf <clifford@clifford.at>
+ *  
+ *  Permission to use, copy, modify, and/or distribute this software for any
+ *  purpose with or without fee is hereby granted, provided that the above
+ *  copyright notice and this permission notice appear in all copies.
+ *  
+ *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "ezminisat.h"
+#include <stdio.h>
+
+struct xorshift128 {
+	uint32_t x, y, z, w;
+	xorshift128() {
+		x = 123456789;
+		y = 362436069;
+		z = 521288629;
+		w = 88675123;
+	}
+	uint32_t operator()() {
+		uint32_t t = x ^ (x << 11);
+		x = y; y = z; z = w;
+		w ^= (w >> 19) ^ t ^ (t >> 8);
+		return w;
+	}
+};
+
+bool test(ezSAT &sat, int assumption = 0)
+{
+	for (auto id : sat.assumed())
+		printf("%s\n", sat.to_string(id).c_str());
+	if (assumption)
+		printf("%s\n", sat.to_string(assumption).c_str());
+
+	std::vector<int> modelExpressions;
+	std::vector<bool> modelValues;
+
+	for (int id = 1; id <= sat.numLiterals(); id++)
+		if (sat.bound(id))
+			modelExpressions.push_back(id);
+
+	if (sat.solve(modelExpressions, modelValues, assumption)) {
+		printf("satisfiable:");
+		for (int i = 0; i < int(modelExpressions.size()); i++)
+			printf(" %s=%d", sat.to_string(modelExpressions[i]).c_str(), int(modelValues[i]));
+		printf("\n\n");
+		return true;
+	} else {
+		printf("not satisfiable.\n\n");
+		return false;
+	}
+}
+
+// ------------------------------------------------------------------------------------------------------------
+
+void test_simple()
+{
+	printf("==== %s ====\n\n", __PRETTY_FUNCTION__);
+
+	ezSAT sat;
+	sat.assume(sat.OR("A", "B"));
+	sat.assume(sat.NOT(sat.AND("A", "B")));
+	test(sat);
+}
+
+// ------------------------------------------------------------------------------------------------------------
+
+void test_basic_operators(ezSAT &sat, xorshift128 &rng, int iter, bool buildTrees, bool buildClusters, std::vector<bool> &log)
+{
+	int vars[6] = {
+		sat.VAR("A"), sat.VAR("B"), sat.VAR("C"),
+		sat.NOT("A"), sat.NOT("B"), sat.NOT("C")
+	};
+	for (int i = 0; i < iter; i++) {
+		int assumption = 0, op = rng() % 6, to = rng() % 6;
+		int a = vars[rng() % 6], b = vars[rng() % 6], c = vars[rng() % 6];
+		// printf("--> %d %d:%s %d:%s %d:%s\n", op, a, sat.to_string(a).c_str(), b, sat.to_string(b).c_str(), c, sat.to_string(c).c_str());
+		switch (op)
+		{
+		case 0:
+			assumption = sat.NOT(a);
+			break;
+		case 1:
+			assumption = sat.AND(a, b);
+			break;
+		case 2:
+			assumption = sat.OR(a, b);
+			break;
+		case 3:
+			assumption = sat.XOR(a, b);
+			break;
+		case 4:
+			assumption = sat.IFF(a, b);
+			break;
+		case 5:
+			assumption = sat.ITE(a, b, c);
+			break;
+		}
+		// printf("  --> %d:%s\n", to, sat.to_string(assumption).c_str());
+		if (buildTrees)
+			vars[to] = assumption;
+		if (!buildClusters)
+			sat.clear();
+		sat.assume(assumption);
+		if (sat.numCnfVariables() < 15) {
+			printf("%d:\n", int(log.size()));
+			log.push_back(test(sat));
+		} else {
+			// printf("** skipping large problem **\n");
+		}
+	}
+}
+
+void test_basic_operators(ezSAT &sat, std::vector<bool> &log)
+{
+	printf("-- %s --\n\n", __PRETTY_FUNCTION__);
+
+	xorshift128 rng;
+	test_basic_operators(sat, rng, 1000, false, false, log);
+	for (int i = 0; i < 100; i++)
+		test_basic_operators(sat, rng, 10, true, false, log);
+	for (int i = 0; i < 100; i++)
+		test_basic_operators(sat, rng, 10, false, true, log);
+}
+
+void test_basic_operators()
+{
+	printf("==== %s ====\n\n", __PRETTY_FUNCTION__);
+
+	ezSAT sat;
+	ezMiniSAT miniSat;
+	std::vector<bool> logSat, logMiniSat;
+
+	test_basic_operators(sat, logSat);
+	test_basic_operators(miniSat, logMiniSat);
+
+	if (logSat != logMiniSat) {
+		printf("Differences between logSat and logMiniSat:");
+		for (int i = 0; i < int(std::max(logSat.size(), logMiniSat.size())); i++)
+			if (i >= int(logSat.size()) || i >= int(logMiniSat.size()) || logSat[i] != logMiniSat[i])
+				printf(" %d", i);
+		printf("\n");
+		abort();
+	} else {
+		printf("Completed %d tests with identical results with ezSAT and ezMiniSAT.\n\n", int(logSat.size()));
+	}
+}
+
+// ------------------------------------------------------------------------------------------------------------
+
+void test_xorshift32_try(ezSAT &sat, uint32_t input_pattern)
+{
+	uint32_t output_pattern = input_pattern;
+	output_pattern ^= output_pattern << 13;
+	output_pattern ^= output_pattern >> 17;
+	output_pattern ^= output_pattern << 5;
+
+	std::vector<int> modelExpressions;
+	std::vector<int> forwardAssumptions, backwardAssumptions;
+	std::vector<bool> forwardModel, backwardModel;
+
+	sat.vec_append(modelExpressions, sat.vec_var("i", 32));
+	sat.vec_append(modelExpressions, sat.vec_var("o", 32));
+
+	sat.vec_append_unsigned(forwardAssumptions,  sat.vec_var("i", 32), input_pattern);
+	sat.vec_append_unsigned(backwardAssumptions,  sat.vec_var("o", 32), output_pattern);
+
+	if (!sat.solve(modelExpressions, backwardModel, backwardAssumptions)) {
+		printf("backward solving failed!\n");
+		abort();
+	}
+
+	if (!sat.solve(modelExpressions, forwardModel, forwardAssumptions)) {
+		printf("forward solving failed!\n");
+		abort();
+	}
+
+	printf("xorshift32 test with input pattern 0x%08x:\n", input_pattern);
+
+	printf("forward  solution: input=0x%08x output=0x%08x\n",
+			(unsigned int)sat.vec_model_get_unsigned(modelExpressions, forwardModel, sat.vec_var("i", 32)),
+			(unsigned int)sat.vec_model_get_unsigned(modelExpressions, forwardModel, sat.vec_var("o", 32)));
+
+	printf("backward solution: input=0x%08x output=0x%08x\n",
+			(unsigned int)sat.vec_model_get_unsigned(modelExpressions, backwardModel, sat.vec_var("i", 32)),
+			(unsigned int)sat.vec_model_get_unsigned(modelExpressions, backwardModel, sat.vec_var("o", 32)));
+
+	if (forwardModel != backwardModel) {
+		printf("forward and backward results are inconsistend!\n");
+		abort();
+	}
+
+	printf("passed.\n\n");
+}
+
+void test_xorshift32()
+{
+	printf("==== %s ====\n\n", __PRETTY_FUNCTION__);
+
+	ezMiniSAT sat;
+	xorshift128 rng;
+
+	std::vector<int> bits = sat.vec_var("i", 32);
+
+	bits = sat.vec_xor(bits, sat.vec_shl(bits, 13));
+	bits = sat.vec_xor(bits, sat.vec_shr(bits, 17));
+	bits = sat.vec_xor(bits, sat.vec_shl(bits,  5));
+
+	sat.vec_set(bits, sat.vec_var("o", 32));
+
+	test_xorshift32_try(sat, 0);
+	test_xorshift32_try(sat, 314159265);
+	test_xorshift32_try(sat, rng());
+	test_xorshift32_try(sat, rng());
+	test_xorshift32_try(sat, rng());
+	test_xorshift32_try(sat, rng());
+}
+
+// ------------------------------------------------------------------------------------------------------------
+
+#define CHECK(_expr1, _expr2) check(#_expr1, _expr1, #_expr2, _expr2)
+
+void check(const char *expr1_str, bool expr1, const char *expr2_str, bool expr2)
+{
+	if (expr1 == expr2) {
+		printf("[ %s ] == [ %s ] .. ok (%s == %s)\n", expr1_str, expr2_str, expr1 ? "true" : "false", expr2 ? "true" : "false");
+	} else {
+		printf("[ %s ] != [ %s ] .. ERROR (%s != %s)\n", expr1_str, expr2_str, expr1 ? "true" : "false", expr2 ? "true" : "false");
+		abort();
+	}
+}
+
+void test_signed(int8_t a, int8_t b, int8_t c)
+{
+	ezSAT sat;
+
+	std::vector<int> av = sat.vec_const_signed(a, 8);
+	std::vector<int> bv = sat.vec_const_signed(b, 8);
+	std::vector<int> cv = sat.vec_const_signed(c, 8);
+
+	printf("Testing signed arithmetic using: a=%+d, b=%+d, c=%+d\n", int(a), int(b), int(c));
+
+	CHECK(a <  b+c, sat.solve(sat.vec_lt_signed(av, sat.vec_add(bv, cv))));
+	CHECK(a <= b-c, sat.solve(sat.vec_le_signed(av, sat.vec_sub(bv, cv))));
+
+	CHECK(a >  b+c, sat.solve(sat.vec_gt_signed(av, sat.vec_add(bv, cv))));
+	CHECK(a >= b-c, sat.solve(sat.vec_ge_signed(av, sat.vec_sub(bv, cv))));
+
+	printf("\n");
+}
+
+void test_unsigned(uint8_t a, uint8_t b, uint8_t c)
+{
+	ezSAT sat;
+
+	if (b < c)
+		b ^= c, c ^= b, b ^= c;
+
+	std::vector<int> av = sat.vec_const_unsigned(a, 8);
+	std::vector<int> bv = sat.vec_const_unsigned(b, 8);
+	std::vector<int> cv = sat.vec_const_unsigned(c, 8);
+
+	printf("Testing unsigned arithmetic using: a=%d, b=%d, c=%d\n", int(a), int(b), int(c));
+
+	CHECK(a <  b+c, sat.solve(sat.vec_lt_unsigned(av, sat.vec_add(bv, cv))));
+	CHECK(a <= b-c, sat.solve(sat.vec_le_unsigned(av, sat.vec_sub(bv, cv))));
+
+	CHECK(a >  b+c, sat.solve(sat.vec_gt_unsigned(av, sat.vec_add(bv, cv))));
+	CHECK(a >= b-c, sat.solve(sat.vec_ge_unsigned(av, sat.vec_sub(bv, cv))));
+
+	printf("\n");
+}
+
+void test_count(uint32_t x)
+{
+	ezSAT sat;
+
+	int count = 0;
+	for (int i = 0; i < 32; i++)
+		if (((x >> i) & 1) != 0)
+			count++;
+
+	printf("Testing bit counting using x=0x%08x (%d set bits) .. ", x, count);
+
+	std::vector<int> v = sat.vec_const_unsigned(x, 32);
+
+	std::vector<int> cv6 = sat.vec_const_unsigned(count, 6);
+	std::vector<int> cv4 = sat.vec_const_unsigned(count <= 15 ? count : 15, 4);
+
+	if (cv6 != sat.vec_count(v, 6, false)) {
+		fprintf(stderr, "FAILED 6bit-no-clipping test!\n");
+		abort();
+	}
+	
+	if (cv4 != sat.vec_count(v, 4, true)) {
+		fprintf(stderr, "FAILED 4bit-clipping test!\n");
+		abort();
+	}
+	
+	printf("ok.\n");
+}
+
+void test_arith()
+{
+	printf("==== %s ====\n\n", __PRETTY_FUNCTION__);
+
+	xorshift128 rng;
+
+	for (int i = 0; i < 100; i++)
+		test_signed(rng() % 19 - 10, rng() % 19 - 10, rng() % 19 - 10);
+
+	for (int i = 0; i < 100; i++)
+		test_unsigned(rng() % 10, rng() % 10, rng() % 10);
+
+	test_count(0x00000000);
+	test_count(0xffffffff);
+	for (int i = 0; i < 30; i++)
+		test_count(rng());
+
+	printf("\n");
+}
+
+// ------------------------------------------------------------------------------------------------------------
+
+void test_onehot()
+{
+	printf("==== %s ====\n\n", __PRETTY_FUNCTION__);
+	ezMiniSAT ez;
+
+	int a = ez.literal("a");
+	int b = ez.literal("b");
+	int c = ez.literal("c");
+	int d = ez.literal("d");
+
+	std::vector<int> abcd;
+	abcd.push_back(a);
+	abcd.push_back(b);
+	abcd.push_back(c);
+	abcd.push_back(d);
+
+	ez.assume(ez.onehot(abcd));
+
+	int solution_counter = 0;
+	while (1)
+	{
+		std::vector<bool> modelValues;
+		bool ok = ez.solve(abcd, modelValues);
+
+		if (!ok)
+			break;
+
+		printf("Solution: %d %d %d %d\n", int(modelValues[0]), int(modelValues[1]), int(modelValues[2]), int(modelValues[3]));
+
+		int count_hot = 0;
+		std::vector<int> sol;
+		for (int i = 0; i < 4; i++) {
+			if (modelValues[i])
+				count_hot++;
+			sol.push_back(modelValues[i] ? abcd[i] : ez.NOT(abcd[i]));
+		}
+		ez.assume(ez.NOT(ez.expression(ezSAT::OpAnd, sol)));
+
+		if (count_hot != 1) {
+			fprintf(stderr, "Wrong number of hot bits!\n");
+			abort();
+		}
+
+		solution_counter++;
+	}
+
+	if (solution_counter != 4) {
+		fprintf(stderr, "Wrong number of one-hot solutions!\n");
+		abort();
+	}
+
+	printf("\n");
+}
+
+void test_manyhot()
+{
+	printf("==== %s ====\n\n", __PRETTY_FUNCTION__);
+	ezMiniSAT ez;
+
+	int a = ez.literal("a");
+	int b = ez.literal("b");
+	int c = ez.literal("c");
+	int d = ez.literal("d");
+
+	std::vector<int> abcd;
+	abcd.push_back(a);
+	abcd.push_back(b);
+	abcd.push_back(c);
+	abcd.push_back(d);
+
+	ez.assume(ez.manyhot(abcd, 1, 2));
+
+	int solution_counter = 0;
+	while (1)
+	{
+		std::vector<bool> modelValues;
+		bool ok = ez.solve(abcd, modelValues);
+
+		if (!ok)
+			break;
+
+		printf("Solution: %d %d %d %d\n", int(modelValues[0]), int(modelValues[1]), int(modelValues[2]), int(modelValues[3]));
+
+		int count_hot = 0;
+		std::vector<int> sol;
+		for (int i = 0; i < 4; i++) {
+			if (modelValues[i])
+				count_hot++;
+			sol.push_back(modelValues[i] ? abcd[i] : ez.NOT(abcd[i]));
+		}
+		ez.assume(ez.NOT(ez.expression(ezSAT::OpAnd, sol)));
+
+		if (count_hot != 1 && count_hot != 2) {
+			fprintf(stderr, "Wrong number of hot bits!\n");
+			abort();
+		}
+
+		solution_counter++;
+	}
+
+	if (solution_counter != 4 + 4*3/2) {
+		fprintf(stderr, "Wrong number of one-hot solutions!\n");
+		abort();
+	}
+
+	printf("\n");
+}
+
+void test_ordered()
+{
+	printf("==== %s ====\n\n", __PRETTY_FUNCTION__);
+	ezMiniSAT ez;
+
+	int a = ez.literal("a");
+	int b = ez.literal("b");
+	int c = ez.literal("c");
+
+	int x = ez.literal("x");
+	int y = ez.literal("y");
+	int z = ez.literal("z");
+
+	std::vector<int> abc;
+	abc.push_back(a);
+	abc.push_back(b);
+	abc.push_back(c);
+
+	std::vector<int> xyz;
+	xyz.push_back(x);
+	xyz.push_back(y);
+	xyz.push_back(z);
+
+	ez.assume(ez.ordered(abc, xyz));
+
+	int solution_counter = 0;
+
+	while (1)
+	{
+		std::vector<int> modelVariables;
+		std::vector<bool> modelValues;
+
+		modelVariables.push_back(a);
+		modelVariables.push_back(b);
+		modelVariables.push_back(c);
+
+		modelVariables.push_back(x);
+		modelVariables.push_back(y);
+		modelVariables.push_back(z);
+
+		bool ok = ez.solve(modelVariables, modelValues);
+
+		if (!ok)
+			break;
+
+		printf("Solution: %d %d %d | %d %d %d\n",
+				int(modelValues[0]), int(modelValues[1]), int(modelValues[2]),
+				int(modelValues[3]), int(modelValues[4]), int(modelValues[5]));
+
+		std::vector<int> sol;
+		for (size_t i = 0; i < modelVariables.size(); i++)
+			sol.push_back(modelValues[i] ? modelVariables[i] : ez.NOT(modelVariables[i]));
+		ez.assume(ez.NOT(ez.expression(ezSAT::OpAnd, sol)));
+
+		solution_counter++;
+	}
+
+	if (solution_counter != 8+7+6+5+4+3+2+1) {
+		fprintf(stderr, "Wrong number of solutions!\n");
+		abort();
+	}
+
+	printf("\n");
+}
+
+// ------------------------------------------------------------------------------------------------------------
+
+
+int main()
+{
+	test_simple();
+	test_basic_operators();
+	test_xorshift32();
+	test_arith();
+	test_onehot();
+	test_manyhot();
+	test_ordered();
+	printf("Passed all tests.\n\n");
+	return 0;
+}
+