Initial check in of big integer library

third_party/bigint/testsuite.cc

Index: third_party/bigint/testsuite.cc
diff --git a/third_party/bigint/testsuite.cc b/third_party/bigint/testsuite.cc
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+/* Test suite for the library.  First, it ``tests'' that all the constructs it
+ * uses compile successfully.  Then, its output to stdout is compared to the
+ * expected output automatically extracted from slash-slash comments below.
+ * 
+ * NOTE: For now, the test suite expects a 32-bit system.  On others, some tests
+ * may fail, and it may be ineffective at catching bugs.  TODO: Remedy this. */
+
+#include "BigIntegerLibrary.hh"
+
+#include <string>
+#include <iostream>
+using namespace std;
+
+// Evaluate expr and print the result or "error" as appropriate.
+#define TEST(expr) do {\
+	cout << "Line " << __LINE__ << ": ";\
+	try {\
+		cout << (expr);\
+	} catch (const char *err) {\
+		cout << "error";\
+	}\
+	cout << endl;\
+} while (0)
+
+const BigUnsigned &check(const BigUnsigned &x) {
+	unsigned int l = x.getLength();
+	if (l != 0 && x.getBlock(l-1) == 0)
+		cout << "check: Unzapped number!" << endl;
+	if (l > x.getCapacity())
+		cout << "check: Capacity inconsistent with length!" << endl;
+	return x;
+}
+
+const BigInteger &check(const BigInteger &x) {
+	if (x.getSign() == 0 && !x.getMagnitude().isZero())
+		cout << "check: Sign should not be zero!" << endl;
+	if (x.getSign() != 0 && x.getMagnitude().isZero())
+		cout << "check: Sign should be zero!" << endl;
+	check(x.getMagnitude());
+	return x;
+}
+
+short pathologicalShort = ~((unsigned short)(~0) >> 1);
+int pathologicalInt = ~((unsigned int)(~0) >> 1);
+long pathologicalLong = ~((unsigned long)(~0) >> 1);
+
+int main() {
+
+try {
+
+BigUnsigned z(0), one(1), ten(10);
+TEST(z); //0
+TEST(1); //1
+TEST(10); //10
+
+// TODO: Comprehensively test the general and special cases of each function.
+
+// === Default constructors ===
+
+TEST(check(BigUnsigned())); //0
+TEST(check(BigInteger())); //0
+
+// === Block-array constructors ===
+
+BigUnsigned::Blk myBlocks[3];
+myBlocks[0] = 3;
+myBlocks[1] = 4;
+myBlocks[2] = 0;
+BigUnsigned bu(myBlocks, 3);
+TEST(check(bu)); //17179869187
+TEST(check(BigInteger(myBlocks, 3))); //17179869187
+TEST(check(BigInteger(bu         ))); //17179869187
+
+// For nonzero magnitude, reject zero and invalid signs.
+TEST(check(BigInteger(myBlocks, 3, BigInteger::positive))); //17179869187
+TEST(check(BigInteger(myBlocks, 3, BigInteger::negative))); //-17179869187
+TEST(check(BigInteger(myBlocks, 3, BigInteger::zero    ))); //error
+TEST(check(BigInteger(bu,          BigInteger::positive))); //17179869187
+TEST(check(BigInteger(bu,          BigInteger::negative))); //-17179869187
+TEST(check(BigInteger(bu,          BigInteger::zero    ))); //error
+
+// For zero magnitude, force the sign to zero without error.
+BigUnsigned::Blk myZeroBlocks[1];
+myZeroBlocks[0] = 0;
+TEST(check(BigInteger(myZeroBlocks, 1, BigInteger::positive))); //0
+TEST(check(BigInteger(myZeroBlocks, 1, BigInteger::negative))); //0
+TEST(check(BigInteger(myZeroBlocks, 1, BigInteger::zero    ))); //0
+
+// === BigUnsigned conversion limits ===
+
+TEST(BigUnsigned(0).toUnsignedLong()); //0
+TEST(BigUnsigned(4294967295U).toUnsignedLong()); //4294967295
+TEST(stringToBigUnsigned("4294967296").toUnsignedLong()); //error
+
+TEST(BigUnsigned(0).toLong()); //0
+TEST(BigUnsigned(2147483647).toLong()); //2147483647
+TEST(BigUnsigned(2147483648U).toLong()); //error
+
+// int is the same as long on a 32-bit system
+TEST(BigUnsigned(0).toUnsignedInt()); //0
+TEST(BigUnsigned(4294967295U).toUnsignedInt()); //4294967295
+TEST(stringToBigUnsigned("4294967296").toUnsignedInt()); //error
+
+TEST(BigUnsigned(0).toInt()); //0
+TEST(BigUnsigned(2147483647).toInt()); //2147483647
+TEST(BigUnsigned(2147483648U).toInt()); //error
+
+TEST(BigUnsigned(0).toUnsignedShort()); //0
+TEST(BigUnsigned(65535).toUnsignedShort()); //65535
+TEST(BigUnsigned(65536).toUnsignedShort()); //error
+
+TEST(BigUnsigned(0).toShort()); //0
+TEST(BigUnsigned(32767).toShort()); //32767
+TEST(BigUnsigned(32768).toShort()); //error
+
+// === BigInteger conversion limits ===
+
+TEST(BigInteger(-1).toUnsignedLong()); //error
+TEST(BigInteger(0).toUnsignedLong()); //0
+TEST(BigInteger(4294967295U).toUnsignedLong()); //4294967295
+TEST(stringToBigInteger("4294967296").toUnsignedLong()); //error
+
+TEST(stringToBigInteger("-2147483649").toLong()); //error
+TEST(stringToBigInteger("-2147483648").toLong()); //-2147483648
+TEST(BigInteger(-2147483647).toLong()); //-2147483647
+TEST(BigInteger(0).toLong()); //0
+TEST(BigInteger(2147483647).toLong()); //2147483647
+TEST(BigInteger(2147483648U).toLong()); //error
+
+// int is the same as long on a 32-bit system
+TEST(BigInteger(-1).toUnsignedInt()); //error
+TEST(BigInteger(0).toUnsignedInt()); //0
+TEST(BigInteger(4294967295U).toUnsignedInt()); //4294967295
+TEST(stringToBigInteger("4294967296").toUnsignedInt()); //error
+
+TEST(stringToBigInteger("-2147483649").toInt()); //error
+TEST(stringToBigInteger("-2147483648").toInt()); //-2147483648
+TEST(BigInteger(-2147483647).toInt()); //-2147483647
+TEST(BigInteger(0).toInt()); //0
+TEST(BigInteger(2147483647).toInt()); //2147483647
+TEST(BigInteger(2147483648U).toInt()); //error
+
+TEST(BigInteger(-1).toUnsignedShort()); //error
+TEST(BigInteger(0).toUnsignedShort()); //0
+TEST(BigInteger(65535).toUnsignedShort()); //65535
+TEST(BigInteger(65536).toUnsignedShort()); //error
+
+TEST(BigInteger(-32769).toShort()); //error
+TEST(BigInteger(-32768).toShort()); //-32768
+TEST(BigInteger(-32767).toShort()); //-32767
+TEST(BigInteger(0).toShort()); //0
+TEST(BigInteger(32767).toShort()); //32767
+TEST(BigInteger(32768).toShort()); //error
+
+// === Negative BigUnsigneds ===
+
+// ...during construction
+TEST(BigUnsigned(short(-1))); //error
+TEST(BigUnsigned(pathologicalShort)); //error
+TEST(BigUnsigned(-1)); //error
+TEST(BigUnsigned(pathologicalInt)); //error
+TEST(BigUnsigned(long(-1))); //error
+TEST(BigUnsigned(pathologicalLong)); //error
+
+// ...during subtraction
+TEST(BigUnsigned(5) - BigUnsigned(6)); //error
+TEST(stringToBigUnsigned("314159265358979323") - stringToBigUnsigned("314159265358979324")); //error
+TEST(check(BigUnsigned(5) - BigUnsigned(5))); //0
+TEST(check(stringToBigUnsigned("314159265358979323") - stringToBigUnsigned("314159265358979323"))); //0
+TEST(check(stringToBigUnsigned("4294967296") - BigUnsigned(1))); //4294967295
+
+// === BigUnsigned addition ===
+
+TEST(check(BigUnsigned(0) + 0)); //0
+TEST(check(BigUnsigned(0) + 1)); //1
+// Ordinary carry
+TEST(check(stringToBigUnsigned("8589934591" /* 2^33 - 1*/)
+		+ stringToBigUnsigned("4294967298" /* 2^32 + 2 */))); //12884901889
+// Creation of a new block
+TEST(check(BigUnsigned(0xFFFFFFFFU) + 1)); //4294967296
+
+// === BigUnsigned subtraction ===
+
+TEST(check(BigUnsigned(1) - 0)); //1
+TEST(check(BigUnsigned(1) - 1)); //0
+TEST(check(BigUnsigned(2) - 1)); //1
+// Ordinary borrow
+TEST(check(stringToBigUnsigned("12884901889")
+		- stringToBigUnsigned("4294967298"))); //8589934591
+// Borrow that removes a block
+TEST(check(stringToBigUnsigned("4294967296") - 1)); //4294967295
+
+// === BigUnsigned multiplication and division ===
+
+BigUnsigned a = check(BigUnsigned(314159265) * 358979323);
+TEST(a); //112776680263877595
+TEST(a / 123); //916883579381118
+TEST(a % 123); //81
+
+TEST(BigUnsigned(5) / 0); //error
+
+// === Block accessors ===
+
+BigUnsigned b;
+TEST(b); //0
+TEST(b.getBlock(0)); //0
+b.setBlock(1, 314);
+// Did b grow properly?  And did we zero intermediate blocks?
+TEST(check(b)); //1348619730944
+TEST(b.getLength()); //2
+TEST(b.getBlock(0)); //0
+TEST(b.getBlock(1)); //314
+// Did b shrink properly?
+b.setBlock(1, 0);
+TEST(check(b)); //0
+
+BigUnsigned bb(314);
+bb.setBlock(1, 159);
+// Make sure we used allocateAndCopy, not allocate
+TEST(bb.getBlock(0)); //314
+TEST(bb.getBlock(1)); //159
+// Blocks beyond the number should be zero regardless of whether they are
+// within the capacity.
+bb.add(1, 2);
+TEST(bb.getBlock(0)); //3
+TEST(bb.getBlock(1)); //0
+TEST(bb.getBlock(2)); //0
+TEST(bb.getBlock(314159)); //0
+
+// === Bit accessors ===
+
+TEST(BigUnsigned(0).bitLength()); //0
+TEST(BigUnsigned(1).bitLength()); //1
+TEST(BigUnsigned(4095).bitLength()); //12
+TEST(BigUnsigned(4096).bitLength()); //13
+// 5 billion is between 2^32 (about 4 billion) and 2^33 (about 8 billion).
+TEST(stringToBigUnsigned("5000000000").bitLength()); //33
+
+// 25 is binary 11001.
+BigUnsigned bbb(25);
+TEST(bbb.getBit(4)); //1
+TEST(bbb.getBit(3)); //1
+TEST(bbb.getBit(2)); //0
+TEST(bbb.getBit(1)); //0
+TEST(bbb.getBit(0)); //1
+TEST(bbb.bitLength()); //5
+// Effectively add 2^32.
+bbb.setBit(32, true);
+TEST(bbb); //4294967321
+bbb.setBit(31, true);
+bbb.setBit(32, false);
+TEST(check(bbb)); //2147483673
+
+// === Combining BigUnsigned, BigInteger, and primitive integers ===
+
+BigUnsigned p1 = BigUnsigned(3) * 5;
+TEST(p1); //15
+/* In this case, we would like g++ to implicitly promote the BigUnsigned to a
+ * BigInteger, but it seems to prefer converting the -5 to a BigUnsigned, which
+ * causes an error.  If I take out constructors for BigUnsigned from signed
+ * primitive integers, the BigUnsigned(3) becomes ambiguous, and if I take out
+ * all the constructors but BigUnsigned(unsigned long), g++ uses that
+ * constructor and gets a wrong (positive) answer.  Thus, I think we'll just
+ * have to live with this cast. */
+BigInteger p2 = BigInteger(BigUnsigned(3)) * -5;
+TEST(p2); //-15
+
+// === Test some previous bugs ===
+
+{
+	/* Test that BigInteger division sets the sign to zero.
+	 * Bug reported by David Allen. */
+	BigInteger num(3), denom(5), quotient;
+	num.divideWithRemainder(denom, quotient);
+	check(quotient);
+	num = 5;
+	num.divideWithRemainder(denom, quotient);
+	check(num);
+}
+
+{
+	/* Test that BigInteger subtraction sets the sign properly.
+	 * Bug reported by Samuel Larkin. */
+	BigInteger zero(0), three(3), ans;
+	ans = zero - three;
+	TEST(check(ans).getSign()); //-1
+}
+
+{
+	/* Test that BigInteger multiplication shifts bits properly on systems
+	 * where long is bigger than int.  (Obviously, this would only catch the
+	 * bug when run on such a system.)
+	 * Bug reported by Mohand Mezmaz. */
+	BigInteger f=4; f*=3;
+	TEST(check(f)); //12
+}
+
+{
+	/* Test that bitwise XOR allocates the larger length.
+	 * Bug reported by Sriram Sankararaman. */
+	BigUnsigned a(0), b(3), ans;
+	ans = a ^ b;
+	TEST(ans); //3
+}
+
+{
+	/* Test that an aliased multiplication works.
+	 * Bug reported by Boris Dessy. */
+	BigInteger num(5);
+	num *= num;
+	TEST(check(num)); //25
+}
+
+{
+	/* Test that BigUnsignedInABase(std::string) constructor rejects digits
+	 * too big for the specified base.
+	 * Bug reported by Niakam Kazemi. */
+	TEST(BigUnsignedInABase("f", 10)); //error
+}
+
+} catch (const char *err) {
+	cout << "UNCAUGHT ERROR: " << err << endl;
+}
+
+return 0;
+}