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authorBo Xu <bo_xu@foxitsoftware.com>2014-12-02 13:06:22 -0800
committerBo Xu <bo_xu@foxitsoftware.com>2014-12-02 16:57:19 -0800
commit8ad0040bbb42d7738965eea99e029145cce0b24e (patch)
tree2ebd20da7529d0f0c58618fbd2883fdb1ae71142 /third_party
parent610b751e894371a2933d7ba17efeee325381465d (diff)
downloadpdfium-8ad0040bbb42d7738965eea99e029145cce0b24e.tar.xz
Merge "Add big integer library""
This patch merges the 3 commits in master branch into one
Diffstat (limited to 'third_party')
-rw-r--r--third_party/bigint/BigInteger.cc443
-rw-r--r--third_party/bigint/BigInteger.hh241
-rw-r--r--third_party/bigint/BigIntegerLibrary.hh14
-rw-r--r--third_party/bigint/BigIntegerUtils.cc60
-rw-r--r--third_party/bigint/BigIntegerUtils.hh78
-rw-r--r--third_party/bigint/BigUnsigned.cc727
-rw-r--r--third_party/bigint/BigUnsigned.hh456
-rw-r--r--third_party/bigint/BigUnsignedInABase.cc159
-rw-r--r--third_party/bigint/BigUnsignedInABase.hh128
-rw-r--r--third_party/bigint/LICENSE71
-rw-r--r--third_party/bigint/NumberlikeArray.hh184
11 files changed, 2561 insertions, 0 deletions
diff --git a/third_party/bigint/BigInteger.cc b/third_party/bigint/BigInteger.cc
new file mode 100644
index 0000000000..bac578f974
--- /dev/null
+++ b/third_party/bigint/BigInteger.cc
@@ -0,0 +1,443 @@
+// Copyright 2014 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code by Matt McCutchen, see the LICENSE file.
+
+#include "BigInteger.hh"
+
+void BigInteger::operator =(const BigInteger &x) {
+ // Calls like a = a have no effect
+ if (this == &x)
+ return;
+ // Copy sign
+ sign = x.sign;
+ // Copy the rest
+ mag = x.mag;
+}
+
+BigInteger::BigInteger(const Blk *b, Index blen, Sign s) : mag(b, blen) {
+ switch (s) {
+ case zero:
+ if (!mag.isZero())
+#ifdef FOXIT_CHROME_BUILD
+ abort();
+#else
+ throw "BigInteger::BigInteger(const Blk *, Index, Sign): Cannot use a sign of zero with a nonzero magnitude";
+#endif
+ sign = zero;
+ break;
+ case positive:
+ case negative:
+ // If the magnitude is zero, force the sign to zero.
+ sign = mag.isZero() ? zero : s;
+ break;
+ default:
+ /* g++ seems to be optimizing out this case on the assumption
+ * that the sign is a valid member of the enumeration. Oh well. */
+#ifdef FOXIT_CHROME_BUILD
+ abort();
+#else
+ throw "BigInteger::BigInteger(const Blk *, Index, Sign): Invalid sign";
+#endif
+ }
+}
+
+BigInteger::BigInteger(const BigUnsigned &x, Sign s) : mag(x) {
+ switch (s) {
+ case zero:
+ if (!mag.isZero())
+#ifdef FOXIT_CHROME_BUILD
+ abort();
+#else
+ throw "BigInteger::BigInteger(const BigUnsigned &, Sign): Cannot use a sign of zero with a nonzero magnitude";
+#endif
+ sign = zero;
+ break;
+ case positive:
+ case negative:
+ // If the magnitude is zero, force the sign to zero.
+ sign = mag.isZero() ? zero : s;
+ break;
+ default:
+ /* g++ seems to be optimizing out this case on the assumption
+ * that the sign is a valid member of the enumeration. Oh well. */
+#ifdef FOXIT_CHROME_BUILD
+ abort();
+#else
+ throw "BigInteger::BigInteger(const BigUnsigned &, Sign): Invalid sign";
+#endif
+ }
+}
+
+/* CONSTRUCTION FROM PRIMITIVE INTEGERS
+ * Same idea as in BigUnsigned.cc, except that negative input results in a
+ * negative BigInteger instead of an exception. */
+
+// Done longhand to let us use initialization.
+BigInteger::BigInteger(unsigned long x) : mag(x) { sign = mag.isZero() ? zero : positive; }
+BigInteger::BigInteger(unsigned int x) : mag(x) { sign = mag.isZero() ? zero : positive; }
+BigInteger::BigInteger(unsigned short x) : mag(x) { sign = mag.isZero() ? zero : positive; }
+
+// For signed input, determine the desired magnitude and sign separately.
+
+namespace {
+ template <class X, class UX>
+ BigInteger::Blk magOf(X x) {
+ /* UX(...) cast needed to stop short(-2^15), which negates to
+ * itself, from sign-extending in the conversion to Blk. */
+ return BigInteger::Blk(x < 0 ? UX(-x) : x);
+ }
+ template <class X>
+ BigInteger::Sign signOf(X x) {
+ return (x == 0) ? BigInteger::zero
+ : (x > 0) ? BigInteger::positive
+ : BigInteger::negative;
+ }
+}
+
+BigInteger::BigInteger(long x) : sign(signOf(x)), mag(magOf<long , unsigned long >(x)) {}
+BigInteger::BigInteger(int x) : sign(signOf(x)), mag(magOf<int , unsigned int >(x)) {}
+BigInteger::BigInteger(short x) : sign(signOf(x)), mag(magOf<short, unsigned short>(x)) {}
+
+// CONVERSION TO PRIMITIVE INTEGERS
+
+/* Reuse BigUnsigned's conversion to an unsigned primitive integer.
+ * The friend is a separate function rather than
+ * BigInteger::convertToUnsignedPrimitive to avoid requiring BigUnsigned to
+ * declare BigInteger. */
+template <class X>
+inline X convertBigUnsignedToPrimitiveAccess(const BigUnsigned &a) {
+ return a.convertToPrimitive<X>();
+}
+
+template <class X>
+X BigInteger::convertToUnsignedPrimitive() const {
+ if (sign == negative)
+#ifdef FOXIT_CHROME_BUILD
+ abort();
+#else
+ throw "BigInteger::to<Primitive>: "
+ "Cannot convert a negative integer to an unsigned type";
+#endif
+ else
+ return convertBigUnsignedToPrimitiveAccess<X>(mag);
+}
+
+/* Similar to BigUnsigned::convertToPrimitive, but split into two cases for
+ * nonnegative and negative numbers. */
+template <class X, class UX>
+X BigInteger::convertToSignedPrimitive() const {
+ if (sign == zero)
+ return 0;
+ else if (mag.getLength() == 1) {
+ // The single block might fit in an X. Try the conversion.
+ Blk b = mag.getBlock(0);
+ if (sign == positive) {
+ X x = X(b);
+ if (x >= 0 && Blk(x) == b)
+ return x;
+ } else {
+ X x = -X(b);
+ /* UX(...) needed to avoid rejecting conversion of
+ * -2^15 to a short. */
+ if (x < 0 && Blk(UX(-x)) == b)
+ return x;
+ }
+ // Otherwise fall through.
+ }
+#ifdef FOXIT_CHROME_BUILD
+ abort();
+#else
+ throw "BigInteger::to<Primitive>: "
+ "Value is too big to fit in the requested type";
+#endif
+}
+
+unsigned long BigInteger::toUnsignedLong () const { return convertToUnsignedPrimitive<unsigned long > (); }
+unsigned int BigInteger::toUnsignedInt () const { return convertToUnsignedPrimitive<unsigned int > (); }
+unsigned short BigInteger::toUnsignedShort() const { return convertToUnsignedPrimitive<unsigned short> (); }
+long BigInteger::toLong () const { return convertToSignedPrimitive <long , unsigned long> (); }
+int BigInteger::toInt () const { return convertToSignedPrimitive <int , unsigned int> (); }
+short BigInteger::toShort () const { return convertToSignedPrimitive <short, unsigned short>(); }
+
+// COMPARISON
+BigInteger::CmpRes BigInteger::compareTo(const BigInteger &x) const {
+ // A greater sign implies a greater number
+ if (sign < x.sign)
+ return less;
+ else if (sign > x.sign)
+ return greater;
+ else switch (sign) {
+ // If the signs are the same...
+ case zero:
+ return equal; // Two zeros are equal
+ case positive:
+ // Compare the magnitudes
+ return mag.compareTo(x.mag);
+ case negative:
+ // Compare the magnitudes, but return the opposite result
+ return CmpRes(-mag.compareTo(x.mag));
+ default:
+#ifdef FOXIT_CHROME_BUILD
+ abort();
+#else
+ throw "BigInteger internal error";
+#endif
+ }
+}
+
+/* COPY-LESS OPERATIONS
+ * These do some messing around to determine the sign of the result,
+ * then call one of BigUnsigned's copy-less operations. */
+
+// See remarks about aliased calls in BigUnsigned.cc .
+#define DTRT_ALIASED(cond, op) \
+ if (cond) { \
+ BigInteger tmpThis; \
+ tmpThis.op; \
+ *this = tmpThis; \
+ return; \
+ }
+
+void BigInteger::add(const BigInteger &a, const BigInteger &b) {
+ DTRT_ALIASED(this == &a || this == &b, add(a, b));
+ // If one argument is zero, copy the other.
+ if (a.sign == zero)
+ operator =(b);
+ else if (b.sign == zero)
+ operator =(a);
+ // If the arguments have the same sign, take the
+ // common sign and add their magnitudes.
+ else if (a.sign == b.sign) {
+ sign = a.sign;
+ mag.add(a.mag, b.mag);
+ } else {
+ // Otherwise, their magnitudes must be compared.
+ switch (a.mag.compareTo(b.mag)) {
+ case equal:
+ // If their magnitudes are the same, copy zero.
+ mag = 0;
+ sign = zero;
+ break;
+ // Otherwise, take the sign of the greater, and subtract
+ // the lesser magnitude from the greater magnitude.
+ case greater:
+ sign = a.sign;
+ mag.subtract(a.mag, b.mag);
+ break;
+ case less:
+ sign = b.sign;
+ mag.subtract(b.mag, a.mag);
+ break;
+ }
+ }
+}
+
+void BigInteger::subtract(const BigInteger &a, const BigInteger &b) {
+ // Notice that this routine is identical to BigInteger::add,
+ // if one replaces b.sign by its opposite.
+ DTRT_ALIASED(this == &a || this == &b, subtract(a, b));
+ // If a is zero, copy b and flip its sign. If b is zero, copy a.
+ if (a.sign == zero) {
+ mag = b.mag;
+ // Take the negative of _b_'s, sign, not ours.
+ // Bug pointed out by Sam Larkin on 2005.03.30.
+ sign = Sign(-b.sign);
+ } else if (b.sign == zero)
+ operator =(a);
+ // If their signs differ, take a.sign and add the magnitudes.
+ else if (a.sign != b.sign) {
+ sign = a.sign;
+ mag.add(a.mag, b.mag);
+ } else {
+ // Otherwise, their magnitudes must be compared.
+ switch (a.mag.compareTo(b.mag)) {
+ // If their magnitudes are the same, copy zero.
+ case equal:
+ mag = 0;
+ sign = zero;
+ break;
+ // If a's magnitude is greater, take a.sign and
+ // subtract a from b.
+ case greater:
+ sign = a.sign;
+ mag.subtract(a.mag, b.mag);
+ break;
+ // If b's magnitude is greater, take the opposite
+ // of b.sign and subtract b from a.
+ case less:
+ sign = Sign(-b.sign);
+ mag.subtract(b.mag, a.mag);
+ break;
+ }
+ }
+}
+
+void BigInteger::multiply(const BigInteger &a, const BigInteger &b) {
+ DTRT_ALIASED(this == &a || this == &b, multiply(a, b));
+ // If one object is zero, copy zero and return.
+ if (a.sign == zero || b.sign == zero) {
+ sign = zero;
+ mag = 0;
+ return;
+ }
+ // If the signs of the arguments are the same, the result
+ // is positive, otherwise it is negative.
+ sign = (a.sign == b.sign) ? positive : negative;
+ // Multiply the magnitudes.
+ mag.multiply(a.mag, b.mag);
+}
+
+/*
+ * DIVISION WITH REMAINDER
+ * Please read the comments before the definition of
+ * `BigUnsigned::divideWithRemainder' in `BigUnsigned.cc' for lots of
+ * information you should know before reading this function.
+ *
+ * Following Knuth, I decree that x / y is to be
+ * 0 if y==0 and floor(real-number x / y) if y!=0.
+ * Then x % y shall be x - y*(integer x / y).
+ *
+ * Note that x = y * (x / y) + (x % y) always holds.
+ * In addition, (x % y) is from 0 to y - 1 if y > 0,
+ * and from -(|y| - 1) to 0 if y < 0. (x % y) = x if y = 0.
+ *
+ * Examples: (q = a / b, r = a % b)
+ * a b q r
+ * === === === ===
+ * 4 3 1 1
+ * -4 3 -2 2
+ * 4 -3 -2 -2
+ * -4 -3 1 -1
+ */
+void BigInteger::divideWithRemainder(const BigInteger &b, BigInteger &q) {
+ // Defend against aliased calls;
+ // same idea as in BigUnsigned::divideWithRemainder .
+ if (this == &q)
+#ifdef FOXIT_CHROME_BUILD
+ abort();
+#else
+ throw "BigInteger::divideWithRemainder: Cannot write quotient and remainder into the same variable";
+#endif
+ if (this == &b || &q == &b) {
+ BigInteger tmpB(b);
+ divideWithRemainder(tmpB, q);
+ return;
+ }
+
+ // Division by zero gives quotient 0 and remainder *this
+ if (b.sign == zero) {
+ q.mag = 0;
+ q.sign = zero;
+ return;
+ }
+ // 0 / b gives quotient 0 and remainder 0
+ if (sign == zero) {
+ q.mag = 0;
+ q.sign = zero;
+ return;
+ }
+
+ // Here *this != 0, b != 0.
+
+ // Do the operands have the same sign?
+ if (sign == b.sign) {
+ // Yes: easy case. Quotient is zero or positive.
+ q.sign = positive;
+ } else {
+ // No: harder case. Quotient is negative.
+ q.sign = negative;
+ // Decrease the magnitude of the dividend by one.
+ mag--;
+ /*
+ * We tinker with the dividend before and with the
+ * quotient and remainder after so that the result
+ * comes out right. To see why it works, consider the following
+ * list of examples, where A is the magnitude-decreased
+ * a, Q and R are the results of BigUnsigned division
+ * with remainder on A and |b|, and q and r are the
+ * final results we want:
+ *
+ * a A b Q R q r
+ * -3 -2 3 0 2 -1 0
+ * -4 -3 3 1 0 -2 2
+ * -5 -4 3 1 1 -2 1
+ * -6 -5 3 1 2 -2 0
+ *
+ * It appears that we need a total of 3 corrections:
+ * Decrease the magnitude of a to get A. Increase the
+ * magnitude of Q to get q (and make it negative).
+ * Find r = (b - 1) - R and give it the desired sign.
+ */
+ }
+
+ // Divide the magnitudes.
+ mag.divideWithRemainder(b.mag, q.mag);
+
+ if (sign != b.sign) {
+ // More for the harder case (as described):
+ // Increase the magnitude of the quotient by one.
+ q.mag++;
+ // Modify the remainder.
+ mag.subtract(b.mag, mag);
+ mag--;
+ }
+
+ // Sign of the remainder is always the sign of the divisor b.
+ sign = b.sign;
+
+ // Set signs to zero as necessary. (Thanks David Allen!)
+ if (mag.isZero())
+ sign = zero;
+ if (q.mag.isZero())
+ q.sign = zero;
+
+ // WHEW!!!
+}
+
+// Negation
+void BigInteger::negate(const BigInteger &a) {
+ DTRT_ALIASED(this == &a, negate(a));
+ // Copy a's magnitude
+ mag = a.mag;
+ // Copy the opposite of a.sign
+ sign = Sign(-a.sign);
+}
+
+// INCREMENT/DECREMENT OPERATORS
+
+// Prefix increment
+void BigInteger::operator ++() {
+ if (sign == negative) {
+ mag--;
+ if (mag == 0)
+ sign = zero;
+ } else {
+ mag++;
+ sign = positive; // if not already
+ }
+}
+
+// Postfix increment: same as prefix
+void BigInteger::operator ++(int) {
+ operator ++();
+}
+
+// Prefix decrement
+void BigInteger::operator --() {
+ if (sign == positive) {
+ mag--;
+ if (mag == 0)
+ sign = zero;
+ } else {
+ mag++;
+ sign = negative;
+ }
+}
+
+// Postfix decrement: same as prefix
+void BigInteger::operator --(int) {
+ operator --();
+}
+
diff --git a/third_party/bigint/BigInteger.hh b/third_party/bigint/BigInteger.hh
new file mode 100644
index 0000000000..a239d3c954
--- /dev/null
+++ b/third_party/bigint/BigInteger.hh
@@ -0,0 +1,241 @@
+// Copyright 2014 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code by Matt McCutchen, see the LICENSE file.
+
+#ifndef BIGINTEGER_H
+#define BIGINTEGER_H
+
+#include "BigUnsigned.hh"
+
+/* A BigInteger object represents a signed integer of size limited only by
+ * available memory. BigUnsigneds support most mathematical operators and can
+ * be converted to and from most primitive integer types.
+ *
+ * A BigInteger is just an aggregate of a BigUnsigned and a sign. (It is no
+ * longer derived from BigUnsigned because that led to harmful implicit
+ * conversions.) */
+class BigInteger {
+
+public:
+ typedef BigUnsigned::Blk Blk;
+ typedef BigUnsigned::Index Index;
+ typedef BigUnsigned::CmpRes CmpRes;
+ static const CmpRes
+ less = BigUnsigned::less ,
+ equal = BigUnsigned::equal ,
+ greater = BigUnsigned::greater;
+ // Enumeration for the sign of a BigInteger.
+ enum Sign { negative = -1, zero = 0, positive = 1 };
+
+protected:
+ Sign sign;
+ BigUnsigned mag;
+
+public:
+ // Constructs zero.
+ BigInteger() : sign(zero), mag() {}
+
+ // Copy constructor
+ BigInteger(const BigInteger &x) : sign(x.sign), mag(x.mag) {};
+
+ // Assignment operator
+ void operator=(const BigInteger &x);
+
+ // Constructor that copies from a given array of blocks with a sign.
+ BigInteger(const Blk *b, Index blen, Sign s);
+
+ // Nonnegative constructor that copies from a given array of blocks.
+ BigInteger(const Blk *b, Index blen) : mag(b, blen) {
+ sign = mag.isZero() ? zero : positive;
+ }
+
+ // Constructor from a BigUnsigned and a sign
+ BigInteger(const BigUnsigned &x, Sign s);
+
+ // Nonnegative constructor from a BigUnsigned
+ BigInteger(const BigUnsigned &x) : mag(x) {
+ sign = mag.isZero() ? zero : positive;
+ }
+
+ // Constructors from primitive integer types
+ BigInteger(unsigned long x);
+ BigInteger( long x);
+ BigInteger(unsigned int x);
+ BigInteger( int x);
+ BigInteger(unsigned short x);
+ BigInteger( short x);
+
+ /* Converters to primitive integer types
+ * The implicit conversion operators caused trouble, so these are now
+ * named. */
+ unsigned long toUnsignedLong () const;
+ long toLong () const;
+ unsigned int toUnsignedInt () const;
+ int toInt () const;
+ unsigned short toUnsignedShort() const;
+ short toShort () const;
+protected:
+ // Helper
+ template <class X> X convertToUnsignedPrimitive() const;
+ template <class X, class UX> X convertToSignedPrimitive() const;
+public:
+
+ // ACCESSORS
+ Sign getSign() const { return sign; }
+ /* The client can't do any harm by holding a read-only reference to the
+ * magnitude. */
+ const BigUnsigned &getMagnitude() const { return mag; }
+
+ // Some accessors that go through to the magnitude
+ Index getLength() const { return mag.getLength(); }
+ Index getCapacity() const { return mag.getCapacity(); }
+ Blk getBlock(Index i) const { return mag.getBlock(i); }
+ bool isZero() const { return sign == zero; } // A bit special
+
+ // COMPARISONS
+
+ // Compares this to x like Perl's <=>
+ CmpRes compareTo(const BigInteger &x) const;
+
+ // Ordinary comparison operators
+ bool operator ==(const BigInteger &x) const {
+ return sign == x.sign && mag == x.mag;
+ }
+ bool operator !=(const BigInteger &x) const { return !operator ==(x); };
+ bool operator < (const BigInteger &x) const { return compareTo(x) == less ; }
+ bool operator <=(const BigInteger &x) const { return compareTo(x) != greater; }
+ bool operator >=(const BigInteger &x) const { return compareTo(x) != less ; }
+ bool operator > (const BigInteger &x) const { return compareTo(x) == greater; }
+
+ // OPERATORS -- See the discussion in BigUnsigned.hh.
+ void add (const BigInteger &a, const BigInteger &b);
+ void subtract(const BigInteger &a, const BigInteger &b);
+ void multiply(const BigInteger &a, const BigInteger &b);
+ /* See the comment on BigUnsigned::divideWithRemainder. Semantics
+ * differ from those of primitive integers when negatives and/or zeros
+ * are involved. */
+ void divideWithRemainder(const BigInteger &b, BigInteger &q);
+ void negate(const BigInteger &a);
+
+ /* Bitwise operators are not provided for BigIntegers. Use
+ * getMagnitude to get the magnitude and operate on that instead. */
+
+ BigInteger operator +(const BigInteger &x) const;
+ BigInteger operator -(const BigInteger &x) const;
+ BigInteger operator *(const BigInteger &x) const;
+ BigInteger operator /(const BigInteger &x) const;
+ BigInteger operator %(const BigInteger &x) const;
+ BigInteger operator -() const;
+
+ void operator +=(const BigInteger &x);
+ void operator -=(const BigInteger &x);
+ void operator *=(const BigInteger &x);
+ void operator /=(const BigInteger &x);
+ void operator %=(const BigInteger &x);
+ void flipSign();
+
+ // INCREMENT/DECREMENT OPERATORS
+ void operator ++( );
+ void operator ++(int);
+ void operator --( );
+ void operator --(int);
+};
+
+// NORMAL OPERATORS
+/* These create an object to hold the result and invoke
+ * the appropriate put-here operation on it, passing
+ * this and x. The new object is then returned. */
+inline BigInteger BigInteger::operator +(const BigInteger &x) const {
+ BigInteger ans;
+ ans.add(*this, x);
+ return ans;
+}
+inline BigInteger BigInteger::operator -(const BigInteger &x) const {
+ BigInteger ans;
+ ans.subtract(*this, x);
+ return ans;
+}
+inline BigInteger BigInteger::operator *(const BigInteger &x) const {
+ BigInteger ans;
+ ans.multiply(*this, x);
+ return ans;
+}
+inline BigInteger BigInteger::operator /(const BigInteger &x) const {
+ if (x.isZero())
+#ifdef FOXIT_CHROME_BUILD
+ abort();
+#else
+ throw "BigInteger::operator /: division by zero";
+#endif
+ BigInteger q, r;
+ r = *this;
+ r.divideWithRemainder(x, q);
+ return q;
+}
+inline BigInteger BigInteger::operator %(const BigInteger &x) const {
+ if (x.isZero())
+#ifdef FOXIT_CHROME_BUILD
+ abort();
+#else
+ throw "BigInteger::operator %: division by zero";
+#endif
+ BigInteger q, r;
+ r = *this;
+ r.divideWithRemainder(x, q);
+ return r;
+}
+inline BigInteger BigInteger::operator -() const {
+ BigInteger ans;
+ ans.negate(*this);
+ return ans;
+}
+
+/*
+ * ASSIGNMENT OPERATORS
+ *
+ * Now the responsibility for making a temporary copy if necessary
+ * belongs to the put-here operations. See Assignment Operators in
+ * BigUnsigned.hh.
+ */
+inline void BigInteger::operator +=(const BigInteger &x) {
+ add(*this, x);
+}
+inline void BigInteger::operator -=(const BigInteger &x) {
+ subtract(*this, x);
+}
+inline void BigInteger::operator *=(const BigInteger &x) {
+ multiply(*this, x);
+}
+inline void BigInteger::operator /=(const BigInteger &x) {
+ if (x.isZero())
+#ifdef FOXIT_CHROME_BUILD
+ abort();
+#else
+ throw "BigInteger::operator /=: division by zero";
+#endif
+ /* The following technique is slightly faster than copying *this first
+ * when x is large. */
+ BigInteger q;
+ divideWithRemainder(x, q);
+ // *this contains the remainder, but we overwrite it with the quotient.
+ *this = q;
+}
+inline void BigInteger::operator %=(const BigInteger &x) {
+ if (x.isZero())
+#ifdef FOXIT_CHROME_BUILD
+ abort();
+#else
+ throw "BigInteger::operator %=: division by zero";
+#endif
+ BigInteger q;
+ // Mods *this by x. Don't care about quotient left in q.
+ divideWithRemainder(x, q);
+}
+// This one is trivial
+inline void BigInteger::flipSign() {
+ sign = Sign(-sign);
+}
+
+#endif
diff --git a/third_party/bigint/BigIntegerLibrary.hh b/third_party/bigint/BigIntegerLibrary.hh
new file mode 100644
index 0000000000..2027804dfb
--- /dev/null
+++ b/third_party/bigint/BigIntegerLibrary.hh
@@ -0,0 +1,14 @@
+// Copyright 2014 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code by Matt McCutchen, see the LICENSE file.
+
+// This header file includes all of the library header files.
+
+#include "NumberlikeArray.hh"
+#include "BigUnsigned.hh"
+#include "BigInteger.hh"
+#include "BigUnsignedInABase.hh"
+#include "BigIntegerUtils.hh"
+
diff --git a/third_party/bigint/BigIntegerUtils.cc b/third_party/bigint/BigIntegerUtils.cc
new file mode 100644
index 0000000000..fac8ac34b1
--- /dev/null
+++ b/third_party/bigint/BigIntegerUtils.cc
@@ -0,0 +1,60 @@
+// Copyright 2014 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code by Matt McCutchen, see the LICENSE file.
+
+#include "BigIntegerUtils.hh"
+#include "BigUnsignedInABase.hh"
+
+std::string bigUnsignedToString(const BigUnsigned &x) {
+ return std::string(BigUnsignedInABase(x, 10));
+}
+
+std::string bigIntegerToString(const BigInteger &x) {
+ return (x.getSign() == BigInteger::negative)
+ ? (std::string("-") + bigUnsignedToString(x.getMagnitude()))
+ : (bigUnsignedToString(x.getMagnitude()));
+}
+
+BigUnsigned stringToBigUnsigned(const std::string &s) {
+ return BigUnsigned(BigUnsignedInABase(s, 10));
+}
+
+BigInteger stringToBigInteger(const std::string &s) {
+ // Recognize a sign followed by a BigUnsigned.
+ return (s[0] == '-') ? BigInteger(stringToBigUnsigned(s.substr(1, s.length() - 1)), BigInteger::negative)
+ : (s[0] == '+') ? BigInteger(stringToBigUnsigned(s.substr(1, s.length() - 1)))
+ : BigInteger(stringToBigUnsigned(s));
+}
+
+std::ostream &operator <<(std::ostream &os, const BigUnsigned &x) {
+ BigUnsignedInABase::Base base;
+ long osFlags = os.flags();
+ if (osFlags & os.dec)
+ base = 10;
+ else if (osFlags & os.hex) {
+ base = 16;
+ if (osFlags & os.showbase)
+ os << "0x";
+ } else if (osFlags & os.oct) {
+ base = 8;
+ if (osFlags & os.showbase)
+ os << '0';
+ } else
+#ifdef FOXIT_CHROME_BUILD
+ abort();
+#else
+ throw "std::ostream << BigUnsigned: Could not determine the desired base from output-stream flags";
+#endif
+ std::string s = std::string(BigUnsignedInABase(x, base));
+ os << s;
+ return os;
+}
+
+std::ostream &operator <<(std::ostream &os, const BigInteger &x) {
+ if (x.getSign() == BigInteger::negative)
+ os << '-';
+ os << x.getMagnitude();
+ return os;
+}
diff --git a/third_party/bigint/BigIntegerUtils.hh b/third_party/bigint/BigIntegerUtils.hh
new file mode 100644
index 0000000000..d2f81f48ab
--- /dev/null
+++ b/third_party/bigint/BigIntegerUtils.hh
@@ -0,0 +1,78 @@
+// Copyright 2014 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code by Matt McCutchen, see the LICENSE file.
+
+#ifndef BIGINTEGERUTILS_H
+#define BIGINTEGERUTILS_H
+
+#include "BigInteger.hh"
+#include <string>
+#include <iostream>
+
+/* This file provides:
+ * - Convenient std::string <-> BigUnsigned/BigInteger conversion routines
+ * - std::ostream << operators for BigUnsigned/BigInteger */
+
+// std::string conversion routines. Base 10 only.
+std::string bigUnsignedToString(const BigUnsigned &x);
+std::string bigIntegerToString(const BigInteger &x);
+BigUnsigned stringToBigUnsigned(const std::string &s);
+BigInteger stringToBigInteger(const std::string &s);
+
+// Creates a BigInteger from data such as `char's; read below for details.
+template <class T>
+BigInteger dataToBigInteger(const T* data, BigInteger::Index length, BigInteger::Sign sign);
+
+// Outputs x to os, obeying the flags `dec', `hex', `bin', and `showbase'.
+std::ostream &operator <<(std::ostream &os, const BigUnsigned &x);
+
+// Outputs x to os, obeying the flags `dec', `hex', `bin', and `showbase'.
+// My somewhat arbitrary policy: a negative sign comes before a base indicator (like -0xFF).
+std::ostream &operator <<(std::ostream &os, const BigInteger &x);
+
+// BEGIN TEMPLATE DEFINITIONS.
+
+/*
+ * Converts binary data to a BigInteger.
+ * Pass an array `data', its length, and the desired sign.
+ *
+ * Elements of `data' may be of any type `T' that has the following
+ * two properties (this includes almost all integral types):
+ *
+ * (1) `sizeof(T)' correctly gives the amount of binary data in one
+ * value of `T' and is a factor of `sizeof(Blk)'.
+ *
+ * (2) When a value of `T' is casted to a `Blk', the low bytes of
+ * the result contain the desired binary data.
+ */
+template <class T>
+BigInteger dataToBigInteger(const T* data, BigInteger::Index length, BigInteger::Sign sign) {
+ // really ceiling(numBytes / sizeof(BigInteger::Blk))
+ unsigned int pieceSizeInBits = 8 * sizeof(T);
+ unsigned int piecesPerBlock = sizeof(BigInteger::Blk) / sizeof(T);
+ unsigned int numBlocks = (length + piecesPerBlock - 1) / piecesPerBlock;
+
+ // Allocate our block array
+ BigInteger::Blk *blocks = new BigInteger::Blk[numBlocks];
+
+ BigInteger::Index blockNum, pieceNum, pieceNumHere;
+
+ // Convert
+ for (blockNum = 0, pieceNum = 0; blockNum < numBlocks; blockNum++) {
+ BigInteger::Blk curBlock = 0;
+ for (pieceNumHere = 0; pieceNumHere < piecesPerBlock && pieceNum < length;
+ pieceNumHere++, pieceNum++)
+ curBlock |= (BigInteger::Blk(data[pieceNum]) << (pieceSizeInBits * pieceNumHere));
+ blocks[blockNum] = curBlock;
+ }
+
+ // Create the BigInteger.
+ BigInteger x(blocks, numBlocks, sign);
+
+ delete [] blocks;
+ return x;
+}
+
+#endif
diff --git a/third_party/bigint/BigUnsigned.cc b/third_party/bigint/BigUnsigned.cc
new file mode 100644
index 0000000000..863fadcb39
--- /dev/null
+++ b/third_party/bigint/BigUnsigned.cc
@@ -0,0 +1,727 @@
+// Copyright 2014 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code by Matt McCutchen, see the LICENSE file.
+
+#include "BigUnsigned.hh"
+
+// Memory management definitions have moved to the bottom of NumberlikeArray.hh.
+
+// The templates used by these constructors and converters are at the bottom of
+// BigUnsigned.hh.
+
+BigUnsigned::BigUnsigned(unsigned long x) { initFromPrimitive (x); }
+BigUnsigned::BigUnsigned(unsigned int x) { initFromPrimitive (x); }
+BigUnsigned::BigUnsigned(unsigned short x) { initFromPrimitive (x); }
+BigUnsigned::BigUnsigned( long x) { initFromSignedPrimitive(x); }
+BigUnsigned::BigUnsigned( int x) { initFromSignedPrimitive(x); }
+BigUnsigned::BigUnsigned( short x) { initFromSignedPrimitive(x); }
+
+unsigned long BigUnsigned::toUnsignedLong () const { return convertToPrimitive <unsigned long >(); }
+unsigned int BigUnsigned::toUnsignedInt () const { return convertToPrimitive <unsigned int >(); }
+unsigned short BigUnsigned::toUnsignedShort() const { return convertToPrimitive <unsigned short>(); }
+long BigUnsigned::toLong () const { return convertToSignedPrimitive< long >(); }
+int BigUnsigned::toInt () const { return convertToSignedPrimitive< int >(); }
+short BigUnsigned::toShort () const { return convertToSignedPrimitive< short>(); }
+
+// BIT/BLOCK ACCESSORS
+
+void BigUnsigned::setBlock(Index i, Blk newBlock) {
+ if (newBlock == 0) {
+ if (i < len) {
+ blk[i] = 0;
+ zapLeadingZeros();
+ }
+ // If i >= len, no effect.
+ } else {
+ if (i >= len) {
+ // The nonzero block extends the number.
+ allocateAndCopy(i+1);
+ // Zero any added blocks that we aren't setting.
+ for (Index j = len; j < i; j++)
+ blk[j] = 0;
+ len = i+1;
+ }
+ blk[i] = newBlock;
+ }
+}
+
+/* Evidently the compiler wants BigUnsigned:: on the return type because, at
+ * that point, it hasn't yet parsed the BigUnsigned:: on the name to get the
+ * proper scope. */
+BigUnsigned::Index BigUnsigned::bitLength() const {
+ if (isZero())
+ return 0;
+ else {
+ Blk leftmostBlock = getBlock(len - 1);
+ Index leftmostBlockLen = 0;
+ while (leftmostBlock != 0) {
+ leftmostBlock >>= 1;
+ leftmostBlockLen++;
+ }
+ return leftmostBlockLen + (len - 1) * N;
+ }
+}
+
+void BigUnsigned::setBit(Index bi, bool newBit) {
+ Index blockI = bi / N;
+ Blk block = getBlock(blockI), mask = Blk(1) << (bi % N);
+ block = newBit ? (block | mask) : (block & ~mask);
+ setBlock(blockI, block);
+}
+
+// COMPARISON
+BigUnsigned::CmpRes BigUnsigned::compareTo(const BigUnsigned &x) const {
+ // A bigger length implies a bigger number.
+ if (len < x.len)
+ return less;
+ else if (len > x.len)
+ return greater;
+ else {
+ // Compare blocks one by one from left to right.
+ Index i = len;
+ while (i > 0) {
+ i--;
+ if (blk[i] == x.blk[i])
+ continue;
+ else if (blk[i] > x.blk[i])
+ return greater;
+ else
+ return less;
+ }
+ // If no blocks differed, the numbers are equal.
+ return equal;
+ }
+}
+
+// COPY-LESS OPERATIONS
+
+/*
+ * On most calls to copy-less operations, it's safe to read the inputs little by
+ * little and write the outputs little by little. However, if one of the
+ * inputs is coming from the same variable into which the output is to be
+ * stored (an "aliased" call), we risk overwriting the input before we read it.
+ * In this case, we first compute the result into a temporary BigUnsigned
+ * variable and then copy it into the requested output variable *this.
+ * Each put-here operation uses the DTRT_ALIASED macro (Do The Right Thing on
+ * aliased calls) to generate code for this check.
+ *
+ * I adopted this approach on 2007.02.13 (see Assignment Operators in
+ * BigUnsigned.hh). Before then, put-here operations rejected aliased calls
+ * with an exception. I think doing the right thing is better.
+ *
+ * Some of the put-here operations can probably handle aliased calls safely
+ * without the extra copy because (for example) they process blocks strictly
+ * right-to-left. At some point I might determine which ones don't need the
+ * copy, but my reasoning would need to be verified very carefully. For now
+ * I'll leave in the copy.
+ */
+#define DTRT_ALIASED(cond, op) \
+ if (cond) { \
+ BigUnsigned tmpThis; \
+ tmpThis.op; \
+ *this = tmpThis; \
+ return; \
+ }
+
+
+
+void BigUnsigned::add(const BigUnsigned &a, const BigUnsigned &b) {
+ DTRT_ALIASED(this == &a || this == &b, add(a, b));
+ // If one argument is zero, copy the other.
+ if (a.len == 0) {
+ operator =(b);
+ return;
+ } else if (b.len == 0) {
+ operator =(a);
+ return;
+ }
+ // Some variables...
+ // Carries in and out of an addition stage
+ bool carryIn, carryOut;
+ Blk temp;
+ Index i;
+ // a2 points to the longer input, b2 points to the shorter
+ const BigUnsigned *a2, *b2;
+ if (a.len >= b.len) {
+ a2 = &a;
+ b2 = &b;
+ } else {
+ a2 = &b;
+ b2 = &a;
+ }
+ // Set prelimiary length and make room in this BigUnsigned
+ len = a2->len + 1;
+ allocate(len);
+ // For each block index that is present in both inputs...
+ for (i = 0, carryIn = false; i < b2->len; i++) {
+ // Add input blocks
+ temp = a2->blk[i] + b2->blk[i];
+ // If a rollover occurred, the result is less than either input.
+ // This test is used many times in the BigUnsigned code.
+ carryOut = (temp < a2->blk[i]);
+ // If a carry was input, handle it
+ if (carryIn) {
+ temp++;
+ carryOut |= (temp == 0);
+ }
+ blk[i] = temp; // Save the addition result
+ carryIn = carryOut; // Pass the carry along
+ }
+ // If there is a carry left over, increase blocks until
+ // one does not roll over.
+ for (; i < a2->len && carryIn; i++) {
+ temp = a2->blk[i] + 1;
+ carryIn = (temp == 0);
+ blk[i] = temp;
+ }
+ // If the carry was resolved but the larger number
+ // still has blocks, copy them over.
+ for (; i < a2->len; i++)
+ blk[i] = a2->blk[i];
+ // Set the extra block if there's still a carry, decrease length otherwise
+ if (carryIn)
+ blk[i] = 1;
+ else
+ len--;
+}
+
+void BigUnsigned::subtract(const BigUnsigned &a, const BigUnsigned &b) {
+ DTRT_ALIASED(this == &a || this == &b, subtract(a, b));
+ if (b.len == 0) {
+ // If b is zero, copy a.
+ operator =(a);
+ return;
+ } else if (a.len < b.len)
+ // If a is shorter than b, the result is negative.
+#ifdef FOXIT_CHROME_BUILD
+ abort();
+#else
+ throw "BigUnsigned::subtract: "
+ "Negative result in unsigned calculation";
+#endif
+ // Some variables...
+ bool borrowIn, borrowOut;
+ Blk temp;
+ Index i;
+ // Set preliminary length and make room
+ len = a.len;
+ allocate(len);
+ // For each block index that is present in both inputs...
+ for (i = 0, borrowIn = false; i < b.len; i++) {
+ temp = a.blk[i] - b.blk[i];
+ // If a reverse rollover occurred,
+ // the result is greater than the block from a.
+ borrowOut = (temp > a.blk[i]);
+ // Handle an incoming borrow
+ if (borrowIn) {
+ borrowOut |= (temp == 0);
+ temp--;
+ }
+ blk[i] = temp; // Save the subtraction result
+ borrowIn = borrowOut; // Pass the borrow along
+ }
+ // If there is a borrow left over, decrease blocks until
+ // one does not reverse rollover.
+ for (; i < a.len && borrowIn; i++) {
+ borrowIn = (a.blk[i] == 0);
+ blk[i] = a.blk[i] - 1;
+ }
+ /* If there's still a borrow, the result is negative.
+ * Throw an exception, but zero out this object so as to leave it in a
+ * predictable state. */
+ if (borrowIn) {
+ len = 0;
+#ifdef FOXIT_CHROME_BUILD
+ abort();
+#else
+ throw "BigUnsigned::subtract: Negative result in unsigned calculation";
+#endif
+ } else
+ // Copy over the rest of the blocks
+ for (; i < a.len; i++)
+ blk[i] = a.blk[i];
+ // Zap leading zeros
+ zapLeadingZeros();
+}
+
+/*
+ * About the multiplication and division algorithms:
+ *
+ * I searched unsucessfully for fast C++ built-in operations like the `b_0'
+ * and `c_0' Knuth describes in Section 4.3.1 of ``The Art of Computer
+ * Programming'' (replace `place' by `Blk'):
+ *
+ * ``b_0[:] multiplication of a one-place integer by another one-place
+ * integer, giving a two-place answer;
+ *
+ * ``c_0[:] division of a two-place integer by a one-place integer,
+ * provided that the quotient is a one-place integer, and yielding
+ * also a one-place remainder.''
+ *
+ * I also missed his note that ``[b]y adjusting the word size, if
+ * necessary, nearly all computers will have these three operations
+ * available'', so I gave up on trying to use algorithms similar to his.
+ * A future version of the library might include such algorithms; I
+ * would welcome contributions from others for this.
+ *
+ * I eventually decided to use bit-shifting algorithms. To multiply `a'
+ * and `b', we zero out the result. Then, for each `1' bit in `a', we
+ * shift `b' left the appropriate amount and add it to the result.
+ * Similarly, to divide `a' by `b', we shift `b' left varying amounts,
+ * repeatedly trying to subtract it from `a'. When we succeed, we note
+ * the fact by setting a bit in the quotient. While these algorithms
+ * have the same O(n^2) time complexity as Knuth's, the ``constant factor''
+ * is likely to be larger.
+ *
+ * Because I used these algorithms, which require single-block addition
+ * and subtraction rather than single-block multiplication and division,
+ * the innermost loops of all four routines are very similar. Study one
+ * of them and all will become clear.
+ */
+
+/*
+ * This is a little inline function used by both the multiplication
+ * routine and the division routine.
+ *
+ * `getShiftedBlock' returns the `x'th block of `num << y'.
+ * `y' may be anything from 0 to N - 1, and `x' may be anything from
+ * 0 to `num.len'.
+ *
+ * Two things contribute to this block:
+ *
+ * (1) The `N - y' low bits of `num.blk[x]', shifted `y' bits left.
+ *
+ * (2) The `y' high bits of `num.blk[x-1]', shifted `N - y' bits right.
+ *
+ * But we must be careful if `x == 0' or `x == num.len', in
+ * which case we should use 0 instead of (2) or (1), respectively.
+ *
+ * If `y == 0', then (2) contributes 0, as it should. However,
+ * in some computer environments, for a reason I cannot understand,
+ * `a >> b' means `a >> (b % N)'. This means `num.blk[x-1] >> (N - y)'
+ * will return `num.blk[x-1]' instead of the desired 0 when `y == 0';
+ * the test `y == 0' handles this case specially.
+ */
+inline BigUnsigned::Blk getShiftedBlock(const BigUnsigned &num,
+ BigUnsigned::Index x, unsigned int y) {
+ BigUnsigned::Blk part1 = (x == 0 || y == 0) ? 0 : (num.blk[x - 1] >> (BigUnsigned::N - y));
+ BigUnsigned::Blk part2 = (x == num.len) ? 0 : (num.blk[x] << y);
+ return part1 | part2;
+}
+
+void BigUnsigned::multiply(const BigUnsigned &a, const BigUnsigned &b) {
+ DTRT_ALIASED(this == &a || this == &b, multiply(a, b));
+ // If either a or b is zero, set to zero.
+ if (a.len == 0 || b.len == 0) {
+ len = 0;
+ return;
+ }
+ /*
+ * Overall method:
+ *
+ * Set this = 0.
+ * For each 1-bit of `a' (say the `i2'th bit of block `i'):
+ * Add `b << (i blocks and i2 bits)' to *this.
+ */
+ // Variables for the calculation
+ Index i, j, k;
+ unsigned int i2;
+ Blk temp;
+ bool carryIn, carryOut;
+ // Set preliminary length and make room
+ len = a.len + b.len;
+ allocate(len);
+ // Zero out this object
+ for (i = 0; i < len; i++)
+ blk[i] = 0;
+ // For each block of the first number...
+ for (i = 0; i < a.len; i++) {
+ // For each 1-bit of that block...
+ for (i2 = 0; i2 < N; i2++) {
+ if ((a.blk[i] & (Blk(1) << i2)) == 0)
+ continue;
+ /*
+ * Add b to this, shifted left i blocks and i2 bits.
+ * j is the index in b, and k = i + j is the index in this.
+ *
+ * `getShiftedBlock', a short inline function defined above,
+ * is now used for the bit handling. It replaces the more
+ * complex `bHigh' code, in which each run of the loop dealt
+ * immediately with the low bits and saved the high bits to
+ * be picked up next time. The last run of the loop used to
+ * leave leftover high bits, which were handled separately.
+ * Instead, this loop runs an additional time with j == b.len.
+ * These changes were made on 2005.01.11.
+ */
+ for (j = 0, k = i, carryIn = false; j <= b.len; j++, k++) {
+ /*
+ * The body of this loop is very similar to the body of the first loop
+ * in `add', except that this loop does a `+=' instead of a `+'.
+ */
+ temp = blk[k] + getShiftedBlock(b, j, i2);
+ carryOut = (temp < blk[k]);
+ if (carryIn) {
+ temp++;
+ carryOut |= (temp == 0);
+ }
+ blk[k] = temp;
+ carryIn = carryOut;
+ }
+ // No more extra iteration to deal with `bHigh'.
+ // Roll-over a carry as necessary.
+ for (; carryIn; k++) {
+ blk[k]++;
+ carryIn = (blk[k] == 0);
+ }
+ }
+ }
+ // Zap possible leading zero
+ if (blk[len - 1] == 0)
+ len--;
+}
+
+/*
+ * DIVISION WITH REMAINDER
+ * This monstrous function mods *this by the given divisor b while storing the
+ * quotient in the given object q; at the end, *this contains the remainder.
+ * The seemingly bizarre pattern of inputs and outputs was chosen so that the
+ * function copies as little as possible (since it is implemented by repeated
+ * subtraction of multiples of b from *this).
+ *
+ * "modWithQuotient" might be a better name for this function, but I would
+ * rather not change the name now.
+ */
+void BigUnsigned::divideWithRemainder(const BigUnsigned &b, BigUnsigned &q) {
+ /* Defending against aliased calls is more complex than usual because we
+ * are writing to both *this and q.
+ *
+ * It would be silly to try to write quotient and remainder to the
+ * same variable. Rule that out right away. */
+ if (this == &q)
+#ifdef FOXIT_CHROME_BUILD
+ abort();
+#else
+ throw "BigUnsigned::divideWithRemainder: Cannot write quotient and remainder into the same variable";
+#endif
+ /* Now *this and q are separate, so the only concern is that b might be
+ * aliased to one of them. If so, use a temporary copy of b. */
+ if (this == &b || &q == &b) {
+ BigUnsigned tmpB(b);
+ divideWithRemainder(tmpB, q);
+ return;
+ }
+
+ /*
+ * Knuth's definition of mod (which this function uses) is somewhat
+ * different from the C++ definition of % in case of division by 0.
+ *
+ * We let a / 0 == 0 (it doesn't matter much) and a % 0 == a, no
+ * exceptions thrown. This allows us to preserve both Knuth's demand
+ * that a mod 0 == a and the useful property that
+ * (a / b) * b + (a % b) == a.
+ */
+ if (b.len == 0) {
+ q.len = 0;
+ return;
+ }
+
+ /*
+ * If *this.len < b.len, then *this < b, and we can be sure that b doesn't go into
+ * *this at all. The quotient is 0 and *this is already the remainder (so leave it alone).
+ */
+ if (len < b.len) {
+ q.len = 0;
+ return;
+ }
+
+ // At this point we know (*this).len >= b.len > 0. (Whew!)
+
+ /*
+ * Overall method:
+ *
+ * For each appropriate i and i2, decreasing:
+ * Subtract (b << (i blocks and i2 bits)) from *this, storing the
+ * result in subtractBuf.
+ * If the subtraction succeeds with a nonnegative result:
+ * Turn on bit i2 of block i of the quotient q.
+ * Copy subtractBuf back into *this.
+ * Otherwise bit i2 of block i remains off, and *this is unchanged.
+ *
+ * Eventually q will contain the entire quotient, and *this will
+ * be left with the remainder.
+ *
+ * subtractBuf[x] corresponds to blk[x], not blk[x+i], since 2005.01.11.
+ * But on a single iteration, we don't touch the i lowest blocks of blk
+ * (and don't use those of subtractBuf) because these blocks are
+ * unaffected by the subtraction: we are subtracting
+ * (b << (i blocks and i2 bits)), which ends in at least `i' zero
+ * blocks. */
+ // Variables for the calculation
+ Index i, j, k;
+ unsigned int i2;
+ Blk temp;
+ bool borrowIn, borrowOut;
+
+ /*
+ * Make sure we have an extra zero block just past the value.
+ *
+ * When we attempt a subtraction, we might shift `b' so
+ * its first block begins a few bits left of the dividend,
+ * and then we'll try to compare these extra bits with
+ * a nonexistent block to the left of the dividend. The
+ * extra zero block ensures sensible behavior; we need
+ * an extra block in `subtractBuf' for exactly the same reason.
+ */
+ Index origLen = len; // Save real length.
+ /* To avoid an out-of-bounds access in case of reallocation, allocate
+ * first and then increment the logical length. */
+ allocateAndCopy(len + 1);
+ len++;
+ blk[origLen] = 0; // Zero the added block.
+
+ // subtractBuf holds part of the result of a subtraction; see above.
+ Blk *subtractBuf = new Blk[len];
+
+ // Set preliminary length for quotient and make room
+ q.len = origLen - b.len + 1;
+ q.allocate(q.len);
+ // Zero out the quotient
+ for (i = 0; i < q.len; i++)
+ q.blk[i] = 0;
+
+ // For each possible left-shift of b in blocks...
+ i = q.len;
+ while (i > 0) {
+ i--;
+ // For each possible left-shift of b in bits...
+ // (Remember, N is the number of bits in a Blk.)
+ q.blk[i] = 0;
+ i2 = N;
+ while (i2 > 0) {
+ i2--;
+ /*
+ * Subtract b, shifted left i blocks and i2 bits, from *this,
+ * and store the answer in subtractBuf. In the for loop, `k == i + j'.
+ *
+ * Compare this to the middle section of `multiply'. They
+ * are in many ways analogous. See especially the discussion
+ * of `getShiftedBlock'.
+ */
+ for (j = 0, k = i, borrowIn = false; j <= b.len; j++, k++) {
+ temp = blk[k] - getShiftedBlock(b, j, i2);
+ borrowOut = (temp > blk[k]);
+ if (borrowIn) {
+ borrowOut |= (temp == 0);
+ temp--;
+ }
+ // Since 2005.01.11, indices of `subtractBuf' directly match those of `blk', so use `k'.
+ subtractBuf[k] = temp;
+ borrowIn = borrowOut;
+ }
+ // No more extra iteration to deal with `bHigh'.
+ // Roll-over a borrow as necessary.
+ for (; k < origLen && borrowIn; k++) {
+ borrowIn = (blk[k] == 0);
+ subtractBuf[k] = blk[k] - 1;
+ }
+ /*
+ * If the subtraction was performed successfully (!borrowIn),
+ * set bit i2 in block i of the quotient.
+ *
+ * Then, copy the portion of subtractBuf filled by the subtraction
+ * back to *this. This portion starts with block i and ends--
+ * where? Not necessarily at block `i + b.len'! Well, we
+ * increased k every time we saved a block into subtractBuf, so
+ * the region of subtractBuf we copy is just [i, k).
+ */
+ if (!borrowIn) {
+ q.blk[i] |= (Blk(1) << i2);
+ while (k > i) {
+ k--;
+ blk[k] = subtractBuf[k];
+ }
+ }
+ }
+ }
+ // Zap possible leading zero in quotient
+ if (q.blk[q.len - 1] == 0)
+ q.len--;
+ // Zap any/all leading zeros in remainder
+ zapLeadingZeros();
+ // Deallocate subtractBuf.
+ // (Thanks to Brad Spencer for noticing my accidental omission of this!)
+ delete [] subtractBuf;
+}
+
+/* BITWISE OPERATORS
+ * These are straightforward blockwise operations except that they differ in
+ * the output length and the necessity of zapLeadingZeros. */
+
+void BigUnsigned::bitAnd(const BigUnsigned &a, const BigUnsigned &b) {
+ DTRT_ALIASED(this == &a || this == &b, bitAnd(a, b));
+ // The bitwise & can't be longer than either operand.
+ len = (a.len >= b.len) ? b.len : a.len;
+ allocate(len);
+ Index i;
+ for (i = 0; i < len; i++)
+ blk[i] = a.blk[i] & b.blk[i];
+ zapLeadingZeros();
+}
+
+void BigUnsigned::bitOr(const BigUnsigned &a, const BigUnsigned &b) {
+ DTRT_ALIASED(this == &a || this == &b, bitOr(a, b));
+ Index i;
+ const BigUnsigned *a2, *b2;
+ if (a.len >= b.len) {
+ a2 = &a;
+ b2 = &b;
+ } else {
+ a2 = &b;
+ b2 = &a;
+ }
+ allocate(a2->len);
+ for (i = 0; i < b2->len; i++)
+ blk[i] = a2->blk[i] | b2->blk[i];
+ for (; i < a2->len; i++)
+ blk[i] = a2->blk[i];
+ len = a2->len;
+ // Doesn't need zapLeadingZeros.
+}
+
+void BigUnsigned::bitXor(const BigUnsigned &a, const BigUnsigned &b) {
+ DTRT_ALIASED(this == &a || this == &b, bitXor(a, b));
+ Index i;
+ const BigUnsigned *a2, *b2;
+ if (a.len >= b.len) {
+ a2 = &a;
+ b2 = &b;
+ } else {
+ a2 = &b;
+ b2 = &a;
+ }
+ allocate(a2->len);
+ for (i = 0; i < b2->len; i++)
+ blk[i] = a2->blk[i] ^ b2->blk[i];
+ for (; i < a2->len; i++)
+ blk[i] = a2->blk[i];
+ len = a2->len;
+ zapLeadingZeros();
+}
+
+void BigUnsigned::bitShiftLeft(const BigUnsigned &a, int b) {
+ DTRT_ALIASED(this == &a, bitShiftLeft(a, b));
+ if (b < 0) {
+ if (b << 1 == 0)
+#ifdef FOXIT_CHROME_BUILD
+ abort();
+#else
+ throw "BigUnsigned::bitShiftLeft: "
+ "Pathological shift amount not implemented";
+#endif
+ else {
+ bitShiftRight(a, -b);
+ return;
+ }
+ }
+ Index shiftBlocks = b / N;
+ unsigned int shiftBits = b % N;
+ // + 1: room for high bits nudged left into another block
+ len = a.len + shiftBlocks + 1;
+ allocate(len);
+ Index i, j;
+ for (i = 0; i < shiftBlocks; i++)
+ blk[i] = 0;
+ for (j = 0, i = shiftBlocks; j <= a.len; j++, i++)
+ blk[i] = getShiftedBlock(a, j, shiftBits);
+ // Zap possible leading zero
+ if (blk[len - 1] == 0)
+ len--;
+}
+
+void BigUnsigned::bitShiftRight(const BigUnsigned &a, int b) {
+ DTRT_ALIASED(this == &a, bitShiftRight(a, b));
+ if (b < 0) {
+ if (b << 1 == 0)
+#ifdef FOXIT_CHROME_BUILD
+ abort();
+#else
+ throw "BigUnsigned::bitShiftRight: "
+ "Pathological shift amount not implemented";
+#endif
+ else {
+ bitShiftLeft(a, -b);
+ return;
+ }
+ }
+ // This calculation is wacky, but expressing the shift as a left bit shift
+ // within each block lets us use getShiftedBlock.
+ Index rightShiftBlocks = (b + N - 1) / N;
+ unsigned int leftShiftBits = N * rightShiftBlocks - b;
+ // Now (N * rightShiftBlocks - leftShiftBits) == b
+ // and 0 <= leftShiftBits < N.
+ if (rightShiftBlocks >= a.len + 1) {
+ // All of a is guaranteed to be shifted off, even considering the left
+ // bit shift.
+ len = 0;
+ return;
+ }
+ // Now we're allocating a positive amount.
+ // + 1: room for high bits nudged left into another block
+ len = a.len + 1 - rightShiftBlocks;
+ allocate(len);
+ Index i, j;
+ for (j = rightShiftBlocks, i = 0; j <= a.len; j++, i++)
+ blk[i] = getShiftedBlock(a, j, leftShiftBits);
+ // Zap possible leading zero
+ if (blk[len - 1] == 0)
+ len--;
+}
+
+// INCREMENT/DECREMENT OPERATORS
+
+// Prefix increment
+void BigUnsigned::operator ++() {
+ Index i;
+ bool carry = true;
+ for (i = 0; i < len && carry; i++) {
+ blk[i]++;
+ carry = (blk[i] == 0);
+ }
+ if (carry) {
+ // Allocate and then increase length, as in divideWithRemainder
+ allocateAndCopy(len + 1);
+ len++;
+ blk[i] = 1;
+ }
+}
+
+// Postfix increment: same as prefix
+void BigUnsigned::operator ++(int) {
+ operator ++();
+}
+
+// Prefix decrement
+void BigUnsigned::operator --() {
+ if (len == 0)
+#ifdef FOXIT_CHROME_BUILD
+ abort();
+#else
+ throw "BigUnsigned::operator --(): Cannot decrement an unsigned zero";
+#endif
+ Index i;
+ bool borrow = true;
+ for (i = 0; borrow; i++) {
+ borrow = (blk[i] == 0);
+ blk[i]--;
+ }
+ // Zap possible leading zero (there can only be one)
+ if (blk[len - 1] == 0)
+ len--;
+}
+
+// Postfix decrement: same as prefix
+void BigUnsigned::operator --(int) {
+ operator --();
+}
diff --git a/third_party/bigint/BigUnsigned.hh b/third_party/bigint/BigUnsigned.hh
new file mode 100644
index 0000000000..accd4d6782
--- /dev/null
+++ b/third_party/bigint/BigUnsigned.hh
@@ -0,0 +1,456 @@
+// Copyright 2014 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code by Matt McCutchen, see the LICENSE file.
+
+#ifndef BIGUNSIGNED_H
+#define BIGUNSIGNED_H
+
+#include "NumberlikeArray.hh"
+
+/* A BigUnsigned object represents a nonnegative integer of size limited only by
+ * available memory. BigUnsigneds support most mathematical operators and can
+ * be converted to and from most primitive integer types.
+ *
+ * The number is stored as a NumberlikeArray of unsigned longs as if it were
+ * written in base 256^sizeof(unsigned long). The least significant block is
+ * first, and the length is such that the most significant block is nonzero. */
+class BigUnsigned : protected NumberlikeArray<unsigned long> {
+
+public:
+ // Enumeration for the result of a comparison.
+ enum CmpRes { less = -1, equal = 0, greater = 1 };
+
+ // BigUnsigneds are built with a Blk type of unsigned long.
+ typedef unsigned long Blk;
+
+ typedef NumberlikeArray<Blk>::Index Index;
+ using NumberlikeArray<Blk>::N;
+
+protected:
+ // Creates a BigUnsigned with a capacity; for internal use.
+ BigUnsigned(int, Index c) : NumberlikeArray<Blk>(0, c) {}
+
+ // Decreases len to eliminate any leading zero blocks.
+ void zapLeadingZeros() {
+ while (len > 0 && blk[len - 1] == 0)
+ len--;
+ }
+
+public:
+ // Constructs zero.
+ BigUnsigned() : NumberlikeArray<Blk>() {}
+
+ // Copy constructor
+ BigUnsigned(const BigUnsigned &x) : NumberlikeArray<Blk>(x) {}
+
+ // Assignment operator
+ void operator=(const BigUnsigned &x) {
+ NumberlikeArray<Blk>::operator =(x);
+ }
+
+ // Constructor that copies from a given array of blocks.
+ BigUnsigned(const Blk *b, Index blen) : NumberlikeArray<Blk>(b, blen) {
+ // Eliminate any leading zeros we may have been passed.
+ zapLeadingZeros();
+ }
+
+ // Destructor. NumberlikeArray does the delete for us.
+ ~BigUnsigned() {}
+
+ // Constructors from primitive integer types
+ BigUnsigned(unsigned long x);
+ BigUnsigned( long x);
+ BigUnsigned(unsigned int x);
+ BigUnsigned( int x);
+ BigUnsigned(unsigned short x);
+ BigUnsigned( short x);
+protected:
+ // Helpers
+ template <class X> void initFromPrimitive (X x);
+ template <class X> void initFromSignedPrimitive(X x);
+public:
+
+ /* Converters to primitive integer types
+ * The implicit conversion operators caused trouble, so these are now
+ * named. */
+ unsigned long toUnsignedLong () const;
+ long toLong () const;
+ unsigned int toUnsignedInt () const;
+ int toInt () const;
+ unsigned short toUnsignedShort() const;
+ short toShort () const;
+protected:
+ // Helpers
+ template <class X> X convertToSignedPrimitive() const;
+ template <class X> X convertToPrimitive () const;
+public:
+
+ // BIT/BLOCK ACCESSORS
+
+ // Expose these from NumberlikeArray directly.
+ using NumberlikeArray<Blk>::getCapacity;
+ using NumberlikeArray<Blk>::getLength;
+
+ /* Returns the requested block, or 0 if it is beyond the length (as if
+ * the number had 0s infinitely to the left). */
+ Blk getBlock(Index i) const { return i >= len ? 0 : blk[i]; }
+ /* Sets the requested block. The number grows or shrinks as necessary. */
+ void setBlock(Index i, Blk newBlock);
+
+ // The number is zero if and only if the canonical length is zero.
+ bool isZero() const { return NumberlikeArray<Blk>::isEmpty(); }
+
+ /* Returns the length of the number in bits, i.e., zero if the number
+ * is zero and otherwise one more than the largest value of bi for
+ * which getBit(bi) returns true. */
+ Index bitLength() const;
+ /* Get the state of bit bi, which has value 2^bi. Bits beyond the
+ * number's length are considered to be 0. */
+ bool getBit(Index bi) const {
+ return (getBlock(bi / N) & (Blk(1) << (bi % N))) != 0;
+ }
+ /* Sets the state of bit bi to newBit. The number grows or shrinks as
+ * necessary. */
+ void setBit(Index bi, bool newBit);
+
+ // COMPARISONS
+
+ // Compares this to x like Perl's <=>
+ CmpRes compareTo(const BigUnsigned &x) const;
+
+ // Ordinary comparison operators
+ bool operator ==(const BigUnsigned &x) const {
+ return NumberlikeArray<Blk>::operator ==(x);
+ }
+ bool operator !=(const BigUnsigned &x) const {
+ return NumberlikeArray<Blk>::operator !=(x);
+ }
+ bool operator < (const BigUnsigned &x) const { return compareTo(x) == less ; }
+ bool operator <=(const BigUnsigned &x) const { return compareTo(x) != greater; }
+ bool operator >=(const BigUnsigned &x) const { return compareTo(x) != less ; }
+ bool operator > (const BigUnsigned &x) const { return compareTo(x) == greater; }
+
+ /*
+ * BigUnsigned and BigInteger both provide three kinds of operators.
+ * Here ``big-integer'' refers to BigInteger or BigUnsigned.
+ *
+ * (1) Overloaded ``return-by-value'' operators:
+ * +, -, *, /, %, unary -, &, |, ^, <<, >>.
+ * Big-integer code using these operators looks identical to code using
+ * the primitive integer types. These operators take one or two
+ * big-integer inputs and return a big-integer result, which can then
+ * be assigned to a BigInteger variable or used in an expression.
+ * Example:
+ * BigInteger a(1), b = 1;
+ * BigInteger c = a + b;
+ *
+ * (2) Overloaded assignment operators:
+ * +=, -=, *=, /=, %=, flipSign, &=, |=, ^=, <<=, >>=, ++, --.
+ * Again, these are used on big integers just like on ints. They take
+ * one writable big integer that both provides an operand and receives a
+ * result. Most also take a second read-only operand.
+ * Example:
+ * BigInteger a(1), b(1);
+ * a += b;
+ *
+ * (3) Copy-less operations: `add', `subtract', etc.
+ * These named methods take operands as arguments and store the result
+ * in the receiver (*this), avoiding unnecessary copies and allocations.
+ * `divideWithRemainder' is special: it both takes the dividend from and
+ * stores the remainder into the receiver, and it takes a separate
+ * object in which to store the quotient. NOTE: If you are wondering
+ * why these don't return a value, you probably mean to use the
+ * overloaded return-by-value operators instead.
+ *
+ * Examples:
+ * BigInteger a(43), b(7), c, d;
+ *
+ * c = a + b; // Now c == 50.
+ * c.add(a, b); // Same effect but without the two copies.
+ *
+ * c.divideWithRemainder(b, d);
+ * // 50 / 7; now d == 7 (quotient) and c == 1 (remainder).
+ *
+ * // ``Aliased'' calls now do the right thing using a temporary
+ * // copy, but see note on `divideWithRemainder'.
+ * a.add(a, b);
+ */
+
+ // COPY-LESS OPERATIONS
+
+ // These 8: Arguments are read-only operands, result is saved in *this.
+ void add(const BigUnsigned &a, const BigUnsigned &b);
+ void subtract(const BigUnsigned &a, const BigUnsigned &b);
+ void multiply(const BigUnsigned &a, const BigUnsigned &b);
+ void bitAnd(const BigUnsigned &a, const BigUnsigned &b);
+ void bitOr(const BigUnsigned &a, const BigUnsigned &b);
+ void bitXor(const BigUnsigned &a, const BigUnsigned &b);
+ /* Negative shift amounts translate to opposite-direction shifts,
+ * except for -2^(8*sizeof(int)-1) which is unimplemented. */
+ void bitShiftLeft(const BigUnsigned &a, int b);
+ void bitShiftRight(const BigUnsigned &a, int b);
+
+ /* `a.divideWithRemainder(b, q)' is like `q = a / b, a %= b'.
+ * / and % use semantics similar to Knuth's, which differ from the
+ * primitive integer semantics under division by zero. See the
+ * implementation in BigUnsigned.cc for details.
+ * `a.divideWithRemainder(b, a)' throws an exception: it doesn't make
+ * sense to write quotient and remainder into the same variable. */
+ void divideWithRemainder(const BigUnsigned &b, BigUnsigned &q);
+
+ /* `divide' and `modulo' are no longer offered. Use
+ * `divideWithRemainder' instead. */
+
+ // OVERLOADED RETURN-BY-VALUE OPERATORS
+ BigUnsigned operator +(const BigUnsigned &x) const;
+ BigUnsigned operator -(const BigUnsigned &x) const;
+ BigUnsigned operator *(const BigUnsigned &x) const;
+ BigUnsigned operator /(const BigUnsigned &x) const;
+ BigUnsigned operator %(const BigUnsigned &x) const;
+ /* OK, maybe unary minus could succeed in one case, but it really
+ * shouldn't be used, so it isn't provided. */
+ BigUnsigned operator &(const BigUnsigned &x) const;
+ BigUnsigned operator |(const BigUnsigned &x) const;
+ BigUnsigned operator ^(const BigUnsigned &x) const;
+ BigUnsigned operator <<(int b) const;
+ BigUnsigned operator >>(int b) const;
+
+ // OVERLOADED ASSIGNMENT OPERATORS
+ void operator +=(const BigUnsigned &x);
+ void operator -=(const BigUnsigned &x);
+ void operator *=(const BigUnsigned &x);
+ void operator /=(const BigUnsigned &x);
+ void operator %=(const BigUnsigned &x);
+ void operator &=(const BigUnsigned &x);
+ void operator |=(const BigUnsigned &x);
+ void operator ^=(const BigUnsigned &x);
+ void operator <<=(int b);
+ void operator >>=(int b);
+
+ /* INCREMENT/DECREMENT OPERATORS
+ * To discourage messy coding, these do not return *this, so prefix
+ * and postfix behave the same. */
+ void operator ++( );
+ void operator ++(int);
+ void operator --( );
+ void operator --(int);
+
+ // Helper function that needs access to BigUnsigned internals
+ friend Blk getShiftedBlock(const BigUnsigned &num, Index x,
+ unsigned int y);
+
+ // See BigInteger.cc.
+ template <class X>
+ friend X convertBigUnsignedToPrimitiveAccess(const BigUnsigned &a);
+};
+
+/* Implementing the return-by-value and assignment operators in terms of the
+ * copy-less operations. The copy-less operations are responsible for making
+ * any necessary temporary copies to work around aliasing. */
+
+inline BigUnsigned BigUnsigned::operator +(const BigUnsigned &x) const {
+ BigUnsigned ans;
+ ans.add(*this, x);
+ return ans;
+}
+inline BigUnsigned BigUnsigned::operator -(const BigUnsigned &x) const {
+ BigUnsigned ans;
+ ans.subtract(*this, x);
+ return ans;
+}
+inline BigUnsigned BigUnsigned::operator *(const BigUnsigned &x) const {
+ BigUnsigned ans;
+ ans.multiply(*this, x);
+ return ans;
+}
+inline BigUnsigned BigUnsigned::operator /(const BigUnsigned &x) const {
+ if (x.isZero())
+#ifdef FOXIT_CHROME_BUILD
+ abort();
+#else
+ throw "BigUnsigned::operator /: division by zero";
+#endif
+ BigUnsigned q, r;
+ r = *this;
+ r.divideWithRemainder(x, q);
+ return q;
+}
+inline BigUnsigned BigUnsigned::operator %(const BigUnsigned &x) const {
+ if (x.isZero())
+#ifdef FOXIT_CHROME_BUILD
+ abort();
+#else
+ throw "BigUnsigned::operator %: division by zero";
+#endif
+ BigUnsigned q, r;
+ r = *this;
+ r.divideWithRemainder(x, q);
+ return r;
+}
+inline BigUnsigned BigUnsigned::operator &(const BigUnsigned &x) const {
+ BigUnsigned ans;
+ ans.bitAnd(*this, x);
+ return ans;
+}
+inline BigUnsigned BigUnsigned::operator |(const BigUnsigned &x) const {
+ BigUnsigned ans;
+ ans.bitOr(*this, x);
+ return ans;
+}
+inline BigUnsigned BigUnsigned::operator ^(const BigUnsigned &x) const {
+ BigUnsigned ans;
+ ans.bitXor(*this, x);
+ return ans;
+}
+inline BigUnsigned BigUnsigned::operator <<(int b) const {
+ BigUnsigned ans;
+ ans.bitShiftLeft(*this, b);
+ return ans;
+}
+inline BigUnsigned BigUnsigned::operator >>(int b) const {
+ BigUnsigned ans;
+ ans.bitShiftRight(*this, b);
+ return ans;
+}
+
+inline void BigUnsigned::operator +=(const BigUnsigned &x) {
+ add(*this, x);
+}
+inline void BigUnsigned::operator -=(const BigUnsigned &x) {
+ subtract(*this, x);
+}
+inline void BigUnsigned::operator *=(const BigUnsigned &x) {
+ multiply(*this, x);
+}
+inline void BigUnsigned::operator /=(const BigUnsigned &x) {
+ if (x.isZero())
+#ifdef FOXIT_CHROME_BUILD
+ abort();
+#else
+ throw "BigUnsigned::operator /=: division by zero";
+#endif
+ /* The following technique is slightly faster than copying *this first
+ * when x is large. */
+ BigUnsigned q;
+ divideWithRemainder(x, q);
+ // *this contains the remainder, but we overwrite it with the quotient.
+ *this = q;
+}
+inline void BigUnsigned::operator %=(const BigUnsigned &x) {
+ if (x.isZero())
+#ifdef FOXIT_CHROME_BUILD
+ abort();
+#else
+ throw "BigUnsigned::operator %=: division by zero";
+#endif
+ BigUnsigned q;
+ // Mods *this by x. Don't care about quotient left in q.
+ divideWithRemainder(x, q);
+}
+inline void BigUnsigned::operator &=(const BigUnsigned &x) {
+ bitAnd(*this, x);
+}
+inline void BigUnsigned::operator |=(const BigUnsigned &x) {
+ bitOr(*this, x);
+}
+inline void BigUnsigned::operator ^=(const BigUnsigned &x) {
+ bitXor(*this, x);
+}
+inline void BigUnsigned::operator <<=(int b) {
+ bitShiftLeft(*this, b);
+}
+inline void BigUnsigned::operator >>=(int b) {
+ bitShiftRight(*this, b);
+}
+
+/* Templates for conversions of BigUnsigned to and from primitive integers.
+ * BigInteger.cc needs to instantiate convertToPrimitive, and the uses in
+ * BigUnsigned.cc didn't do the trick; I think g++ inlined convertToPrimitive
+ * instead of generating linkable instantiations. So for consistency, I put
+ * all the templates here. */
+
+// CONSTRUCTION FROM PRIMITIVE INTEGERS
+
+/* Initialize this BigUnsigned from the given primitive integer. The same
+ * pattern works for all primitive integer types, so I put it into a template to
+ * reduce code duplication. (Don't worry: this is protected and we instantiate
+ * it only with primitive integer types.) Type X could be signed, but x is
+ * known to be nonnegative. */
+template <class X>
+void BigUnsigned::initFromPrimitive(X x) {
+ if (x == 0)
+ ; // NumberlikeArray already initialized us to zero.
+ else {
+ // Create a single block. blk is NULL; no need to delete it.
+ cap = 1;
+ blk = new Blk[1];
+ len = 1;
+ blk[0] = Blk(x);
+ }
+}
+
+/* Ditto, but first check that x is nonnegative. I could have put the check in
+ * initFromPrimitive and let the compiler optimize it out for unsigned-type
+ * instantiations, but I wanted to avoid the warning stupidly issued by g++ for
+ * a condition that is constant in *any* instantiation, even if not in all. */
+template <class X>
+void BigUnsigned::initFromSignedPrimitive(X x) {
+ if (x < 0)
+#ifdef FOXIT_CHROME_BUILD
+ abort();
+#else
+ throw "BigUnsigned constructor: "
+ "Cannot construct a BigUnsigned from a negative number";
+#endif
+ else
+ initFromPrimitive(x);
+}
+
+// CONVERSION TO PRIMITIVE INTEGERS
+
+/* Template with the same idea as initFromPrimitive. This might be slightly
+ * slower than the previous version with the masks, but it's much shorter and
+ * clearer, which is the library's stated goal. */
+template <class X>
+X BigUnsigned::convertToPrimitive() const {
+ if (len == 0)
+ // The number is zero; return zero.
+ return 0;
+ else if (len == 1) {
+ // The single block might fit in an X. Try the conversion.
+ X x = X(blk[0]);
+ // Make sure the result accurately represents the block.
+ if (Blk(x) == blk[0])
+ // Successful conversion.
+ return x;
+ // Otherwise fall through.
+ }
+#ifdef FOXIT_CHROME_BUILD
+ abort();
+#else
+ throw "BigUnsigned::to<Primitive>: "
+ "Value is too big to fit in the requested type";
+#endif
+}
+
+/* Wrap the above in an x >= 0 test to make sure we got a nonnegative result,
+ * not a negative one that happened to convert back into the correct nonnegative
+ * one. (E.g., catch incorrect conversion of 2^31 to the long -2^31.) Again,
+ * separated to avoid a g++ warning. */
+template <class X>
+X BigUnsigned::convertToSignedPrimitive() const {
+ X x = convertToPrimitive<X>();
+ if (x >= 0)
+ return x;
+ else
+#ifdef FOXIT_CHROME_BUILD
+ abort();
+#else
+ throw "BigUnsigned::to(Primitive): "
+ "Value is too big to fit in the requested type";
+#endif
+}
+
+#endif
diff --git a/third_party/bigint/BigUnsignedInABase.cc b/third_party/bigint/BigUnsignedInABase.cc
new file mode 100644
index 0000000000..a24042d538
--- /dev/null
+++ b/third_party/bigint/BigUnsignedInABase.cc
@@ -0,0 +1,159 @@
+// Copyright 2014 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code by Matt McCutchen, see the LICENSE file.
+
+#include "BigUnsignedInABase.hh"
+
+BigUnsignedInABase::BigUnsignedInABase(const Digit *d, Index l, Base base)
+ : NumberlikeArray<Digit>(d, l), base(base) {
+ // Check the base
+ if (base < 2)
+#ifdef FOXIT_CHROME_BUILD
+ abort();
+#else
+ throw "BigUnsignedInABase::BigUnsignedInABase(const Digit *, Index, Base): The base must be at least 2";
+#endif
+
+ // Validate the digits.
+ for (Index i = 0; i < l; i++)
+ if (blk[i] >= base)
+#ifdef FOXIT_CHROME_BUILD
+ abort();
+#else
+ throw "BigUnsignedInABase::BigUnsignedInABase(const Digit *, Index, Base): A digit is too large for the specified base";
+#endif
+
+ // Eliminate any leading zeros we may have been passed.
+ zapLeadingZeros();
+}
+
+namespace {
+ unsigned int bitLen(unsigned int x) {
+ unsigned int len = 0;
+ while (x > 0) {
+ x >>= 1;
+ len++;
+ }
+ return len;
+ }
+ unsigned int ceilingDiv(unsigned int a, unsigned int b) {
+ return (a + b - 1) / b;
+ }
+}
+
+BigUnsignedInABase::BigUnsignedInABase(const BigUnsigned &x, Base base) {
+ // Check the base
+ if (base < 2)
+#ifdef FOXIT_CHROME_BUILD
+ abort();
+#else
+ throw "BigUnsignedInABase(BigUnsigned, Base): The base must be at least 2";
+#endif
+ this->base = base;
+
+ // Get an upper bound on how much space we need
+ int maxBitLenOfX = x.getLength() * BigUnsigned::N;
+ int minBitsPerDigit = bitLen(base) - 1;
+ int maxDigitLenOfX = ceilingDiv(maxBitLenOfX, minBitsPerDigit);
+ len = maxDigitLenOfX; // Another change to comply with `staying in bounds'.
+ allocate(len); // Get the space
+
+ BigUnsigned x2(x), buBase(base);
+ Index digitNum = 0;
+
+ while (!x2.isZero()) {
+ // Get last digit. This is like `lastDigit = x2 % buBase, x2 /= buBase'.
+ BigUnsigned lastDigit(x2);
+ lastDigit.divideWithRemainder(buBase, x2);
+ // Save the digit.
+ blk[digitNum] = lastDigit.toUnsignedShort();
+ // Move on. We can't run out of room: we figured it out above.
+ digitNum++;
+ }
+
+ // Save the actual length.
+ len = digitNum;
+}
+
+BigUnsignedInABase::operator BigUnsigned() const {
+ BigUnsigned ans(0), buBase(base), temp;
+ Index digitNum = len;
+ while (digitNum > 0) {
+ digitNum--;
+ temp.multiply(ans, buBase);
+ ans.add(temp, BigUnsigned(blk[digitNum]));
+ }
+ return ans;
+}
+
+BigUnsignedInABase::BigUnsignedInABase(const std::string &s, Base base) {
+ // Check the base.
+ if (base > 36)
+#ifdef FOXIT_CHROME_BUILD
+ abort();
+#else
+ throw "BigUnsignedInABase(std::string, Base): The default string conversion routines use the symbol set 0-9, A-Z and therefore support only up to base 36. You tried a conversion with a base over 36; write your own string conversion routine.";
+#endif
+ // Save the base.
+ // This pattern is seldom seen in C++, but the analogous ``this.'' is common in Java.
+ this->base = base;
+
+ // `s.length()' is a `size_t', while `len' is a `NumberlikeArray::Index',
+ // also known as an `unsigned int'. Some compilers warn without this cast.
+ len = Index(s.length());
+ allocate(len);
+
+ Index digitNum, symbolNumInString;
+ for (digitNum = 0; digitNum < len; digitNum++) {
+ symbolNumInString = len - 1 - digitNum;
+ char theSymbol = s[symbolNumInString];
+ if (theSymbol >= '0' && theSymbol <= '9')
+ blk[digitNum] = theSymbol - '0';
+ else if (theSymbol >= 'A' && theSymbol <= 'Z')
+ blk[digitNum] = theSymbol - 'A' + 10;
+ else if (theSymbol >= 'a' && theSymbol <= 'z')
+ blk[digitNum] = theSymbol - 'a' + 10;
+ else
+#ifdef FOXIT_CHROME_BUILD
+ abort();
+#else
+ throw "BigUnsignedInABase(std::string, Base): Bad symbol in input. Only 0-9, A-Z, a-z are accepted.";
+#endif
+
+ if (blk[digitNum] >= base)
+#ifdef FOXIT_CHROME_BUILD
+ abort();
+#else
+ throw "BigUnsignedInABase::BigUnsignedInABase(const Digit *, Index, Base): A digit is too large for the specified base";
+#endif
+ }
+ zapLeadingZeros();
+}
+
+BigUnsignedInABase::operator std::string() const {
+ if (base > 36)
+#ifdef FOXIT_CHROME_BUILD
+ abort();
+#else
+ throw "BigUnsignedInABase ==> std::string: The default string conversion routines use the symbol set 0-9, A-Z and therefore support only up to base 36. You tried a conversion with a base over 36; write your own string conversion routine.";
+#endif
+ if (len == 0)
+ return std::string("0");
+ // Some compilers don't have push_back, so use a char * buffer instead.
+ char *s = new char[len + 1];
+ s[len] = '\0';
+ Index digitNum, symbolNumInString;
+ for (symbolNumInString = 0; symbolNumInString < len; symbolNumInString++) {
+ digitNum = len - 1 - symbolNumInString;
+ Digit theDigit = blk[digitNum];
+ if (theDigit < 10)
+ s[symbolNumInString] = char('0' + theDigit);
+ else
+ s[symbolNumInString] = char('A' + theDigit - 10);
+ }
+ std::string s2(s);
+ delete [] s;
+ return s2;
+}
diff --git a/third_party/bigint/BigUnsignedInABase.hh b/third_party/bigint/BigUnsignedInABase.hh
new file mode 100644
index 0000000000..dbd2cf904c
--- /dev/null
+++ b/third_party/bigint/BigUnsignedInABase.hh
@@ -0,0 +1,128 @@
+// Copyright 2014 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code by Matt McCutchen, see the LICENSE file.
+
+#ifndef BIGUNSIGNEDINABASE_H
+#define BIGUNSIGNEDINABASE_H
+
+#include "NumberlikeArray.hh"
+#include "BigUnsigned.hh"
+#include <string>
+
+/*
+ * A BigUnsignedInABase object represents a nonnegative integer of size limited
+ * only by available memory, represented in a user-specified base that can fit
+ * in an `unsigned short' (most can, and this saves memory).
+ *
+ * BigUnsignedInABase is intended as an intermediary class with little
+ * functionality of its own. BigUnsignedInABase objects can be constructed
+ * from, and converted to, BigUnsigneds (requiring multiplication, mods, etc.)
+ * and `std::string's (by switching digit values for appropriate characters).
+ *
+ * BigUnsignedInABase is similar to BigUnsigned. Note the following:
+ *
+ * (1) They represent the number in exactly the same way, except that
+ * BigUnsignedInABase uses ``digits'' (or Digit) where BigUnsigned uses
+ * ``blocks'' (or Blk).
+ *
+ * (2) Both use the management features of NumberlikeArray. (In fact, my desire
+ * to add a BigUnsignedInABase class without duplicating a lot of code led me to
+ * introduce NumberlikeArray.)
+ *
+ * (3) The only arithmetic operation supported by BigUnsignedInABase is an
+ * equality test. Use BigUnsigned for arithmetic.
+ */
+
+class BigUnsignedInABase : protected NumberlikeArray<unsigned short> {
+
+public:
+ // The digits of a BigUnsignedInABase are unsigned shorts.
+ typedef unsigned short Digit;
+ // That's also the type of a base.
+ typedef Digit Base;
+
+protected:
+ // The base in which this BigUnsignedInABase is expressed
+ Base base;
+
+ // Creates a BigUnsignedInABase with a capacity; for internal use.
+ BigUnsignedInABase(int, Index c) : NumberlikeArray<Digit>(0, c) {}
+
+ // Decreases len to eliminate any leading zero digits.
+ void zapLeadingZeros() {
+ while (len > 0 && blk[len - 1] == 0)
+ len--;
+ }
+
+public:
+ // Constructs zero in base 2.
+ BigUnsignedInABase() : NumberlikeArray<Digit>(), base(2) {}
+
+ // Copy constructor
+ BigUnsignedInABase(const BigUnsignedInABase &x) : NumberlikeArray<Digit>(x), base(x.base) {}
+
+ // Assignment operator
+ void operator =(const BigUnsignedInABase &x) {
+ NumberlikeArray<Digit>::operator =(x);
+ base = x.base;
+ }
+
+ // Constructor that copies from a given array of digits.
+ BigUnsignedInABase(const Digit *d, Index l, Base base);
+
+ // Destructor. NumberlikeArray does the delete for us.
+ ~BigUnsignedInABase() {}
+
+ // LINKS TO BIGUNSIGNED
+ BigUnsignedInABase(const BigUnsigned &x, Base base);
+ operator BigUnsigned() const;
+
+ /* LINKS TO STRINGS
+ *
+ * These use the symbols ``0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ'' to
+ * represent digits of 0 through 35. When parsing strings, lowercase is
+ * also accepted.
+ *
+ * All string representations are big-endian (big-place-value digits
+ * first). (Computer scientists have adopted zero-based counting; why
+ * can't they tolerate little-endian numbers?)
+ *
+ * No string representation has a ``base indicator'' like ``0x''.
+ *
+ * An exception is made for zero: it is converted to ``0'' and not the
+ * empty string.
+ *
+ * If you want different conventions, write your own routines to go
+ * between BigUnsignedInABase and strings. It's not hard.
+ */
+ operator std::string() const;
+ BigUnsignedInABase(const std::string &s, Base base);
+
+public:
+
+ // ACCESSORS
+ Base getBase() const { return base; }
+
+ // Expose these from NumberlikeArray directly.
+ using NumberlikeArray<Digit>::getCapacity;
+ using NumberlikeArray<Digit>::getLength;
+
+ /* Returns the requested digit, or 0 if it is beyond the length (as if
+ * the number had 0s infinitely to the left). */
+ Digit getDigit(Index i) const { return i >= len ? 0 : blk[i]; }
+
+ // The number is zero if and only if the canonical length is zero.
+ bool isZero() const { return NumberlikeArray<Digit>::isEmpty(); }
+
+ /* Equality test. For the purposes of this test, two BigUnsignedInABase
+ * values must have the same base to be equal. */
+ bool operator ==(const BigUnsignedInABase &x) const {
+ return base == x.base && NumberlikeArray<Digit>::operator ==(x);
+ }
+ bool operator !=(const BigUnsignedInABase &x) const { return !operator ==(x); }
+
+};
+
+#endif
diff --git a/third_party/bigint/LICENSE b/third_party/bigint/LICENSE
new file mode 100644
index 0000000000..ae9d3dac5f
--- /dev/null
+++ b/third_party/bigint/LICENSE
@@ -0,0 +1,71 @@
+
+ C++ Big Integer Library
+ (see ChangeLog for version)
+
+ http://mattmccutchen.net/bigint/
+
+ Written and maintained by Matt McCutchen <matt@mattmccutchen.net>
+
+You can use this library in a C++ program to do arithmetic on integers of size
+limited only by your computer's memory. The library provides BigUnsigned and
+BigInteger classes that represent nonnegative integers and signed integers,
+respectively. Most of the C++ arithmetic operators are overloaded for these
+classes, so big-integer calculations are as easy as:
+
+ #include "BigIntegerLibrary.hh"
+
+ BigInteger a = 65536;
+ cout << (a * a * a * a * a * a * a * a);
+
+ (prints 340282366920938463463374607431768211456)
+
+The code in `sample.cc' demonstrates the most important features of the library.
+To get started quickly, read the code and explanations in that file and run it.
+If you want more detail or a feature not shown in `sample.cc', consult the
+consult the actual header and source files, which are thoroughly commented.
+
+This library emphasizes ease of use and clarity of implementation over speed;
+some users will prefer GMP (http://swox.com/gmp/), which is faster. The code is
+intended to be reasonably portable across computers and modern C++ compilers; in
+particular, it uses whatever word size the computer provides (32-bit, 64-bit, or
+otherwise).
+
+Compiling programs that use the library
+---------------------------------------
+The library consists of a folder full of C++ header files (`.hh') and source
+files (`.cc'). Your own programs should `#include' the necessary header files
+and link with the source files. A makefile that builds the sample program
+(`sample.cc') is included; you can adapt it to replace the sample with your own
+program.
+
+Alternatively, you can use your own build system or IDE. In that case, you must
+put the library header files where the compiler will find them and arrange to
+have your program linked with the library source files; otherwise, you will get
+errors about missing header files or "undefined references". To learn how to do
+this, consult the documentation for the build system or IDE; don't bother asking
+me. Adding all the library files to your project will work in many IDEs but may
+not be the most desirable approach.
+
+Resources
+---------
+The library's Web site (above) provides links to released versions, the current
+development version, and a mailing list for release announcements, questions,
+bug reports, and other discussion of the library. I would be delighted to hear
+from you if you like this library and/or find a good use for it.
+
+Bugs and enhancements
+---------------------
+The library has been tested by me and others but is by no means bug-free. If
+you find a bug, please report it, whether it comes in the form of compiling
+trouble, a mathematically inaccurate result, or a memory-management blooper
+(since I use Java, these are altogether too common in my C++). I generally fix
+all reported bugs. You are also welcome to request enhancements, but I am
+unlikely to do substantial amounts of work on enhancements at this point.
+
+Legal
+-----
+I, Matt McCutchen, the sole author of the original Big Integer Library, waive my
+copyright to it, placing it in the public domain. The library comes with
+absolutely no warranty.
+
+~~~~
diff --git a/third_party/bigint/NumberlikeArray.hh b/third_party/bigint/NumberlikeArray.hh
new file mode 100644
index 0000000000..f7917809f4
--- /dev/null
+++ b/third_party/bigint/NumberlikeArray.hh
@@ -0,0 +1,184 @@
+// Copyright 2014 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code by Matt McCutchen, see the LICENSE file.
+
+#ifndef NUMBERLIKEARRAY_H
+#define NUMBERLIKEARRAY_H
+
+#include <stdlib.h> // abort()
+// Make sure we have NULL.
+#ifndef NULL
+#define NULL 0
+#endif
+
+/* A NumberlikeArray<Blk> object holds a heap-allocated array of Blk with a
+ * length and a capacity and provides basic memory management features.
+ * BigUnsigned and BigUnsignedInABase both subclass it.
+ *
+ * NumberlikeArray provides no information hiding. Subclasses should use
+ * nonpublic inheritance and manually expose members as desired using
+ * declarations like this:
+ *
+ * public:
+ * NumberlikeArray< the-type-argument >::getLength;
+ */
+template <class Blk>
+class NumberlikeArray {
+public:
+
+ // Type for the index of a block in the array
+ typedef unsigned int Index;
+ // The number of bits in a block, defined below.
+ static const unsigned int N;
+
+ // The current allocated capacity of this NumberlikeArray (in blocks)
+ Index cap;
+ // The actual length of the value stored in this NumberlikeArray (in blocks)
+ Index len;
+ // Heap-allocated array of the blocks (can be NULL if len == 0)
+ Blk *blk;
+
+ // Constructs a ``zero'' NumberlikeArray with the given capacity.
+ NumberlikeArray(Index c) : cap(c), len(0) {
+ blk = (cap > 0) ? (new Blk[cap]) : NULL;
+ }
+
+ /* Constructs a zero NumberlikeArray without allocating a backing array.
+ * A subclass that doesn't know the needed capacity at initialization
+ * time can use this constructor and then overwrite blk without first
+ * deleting it. */
+ NumberlikeArray() : cap(0), len(0) {
+ blk = NULL;
+ }
+
+ // Destructor. Note that `delete NULL' is a no-op.
+ ~NumberlikeArray() {
+ delete [] blk;
+ }
+
+ /* Ensures that the array has at least the requested capacity; may
+ * destroy the contents. */
+ void allocate(Index c);
+
+ /* Ensures that the array has at least the requested capacity; does not
+ * destroy the contents. */
+ void allocateAndCopy(Index c);
+
+ // Copy constructor
+ NumberlikeArray(const NumberlikeArray<Blk> &x);
+
+ // Assignment operator
+ void operator=(const NumberlikeArray<Blk> &x);
+
+ // Constructor that copies from a given array of blocks
+ NumberlikeArray(const Blk *b, Index blen);
+
+ // ACCESSORS
+ Index getCapacity() const { return cap; }
+ Index getLength() const { return len; }
+ Blk getBlock(Index i) const { return blk[i]; }
+ bool isEmpty() const { return len == 0; }
+
+ /* Equality comparison: checks if both objects have the same length and
+ * equal (==) array elements to that length. Subclasses may wish to
+ * override. */
+ bool operator ==(const NumberlikeArray<Blk> &x) const;
+
+ bool operator !=(const NumberlikeArray<Blk> &x) const {
+ return !operator ==(x);
+ }
+};
+
+/* BEGIN TEMPLATE DEFINITIONS. They are present here so that source files that
+ * include this header file can generate the necessary real definitions. */
+
+template <class Blk>
+const unsigned int NumberlikeArray<Blk>::N = 8 * sizeof(Blk);
+
+template <class Blk>
+void NumberlikeArray<Blk>::allocate(Index c) {
+ // If the requested capacity is more than the current capacity...
+ if (c > cap) {
+ // Delete the old number array
+ delete [] blk;
+ // Allocate the new array
+ cap = c;
+ blk = new Blk[cap];
+ }
+}
+
+template <class Blk>
+void NumberlikeArray<Blk>::allocateAndCopy(Index c) {
+ // If the requested capacity is more than the current capacity...
+ if (c > cap) {
+ Blk *oldBlk = blk;
+ // Allocate the new number array
+ cap = c;
+ blk = new Blk[cap];
+ // Copy number blocks
+ Index i;
+ for (i = 0; i < len; i++)
+ blk[i] = oldBlk[i];
+ // Delete the old array
+ delete [] oldBlk;
+ }
+}
+
+template <class Blk>
+NumberlikeArray<Blk>::NumberlikeArray(const NumberlikeArray<Blk> &x)
+ : len(x.len) {
+ // Create array
+ cap = len;
+ blk = new Blk[cap];
+ // Copy blocks
+ Index i;
+ for (i = 0; i < len; i++)
+ blk[i] = x.blk[i];
+}
+
+template <class Blk>
+void NumberlikeArray<Blk>::operator=(const NumberlikeArray<Blk> &x) {
+ /* Calls like a = a have no effect; catch them before the aliasing
+ * causes a problem */
+ if (this == &x)
+ return;
+ // Copy length
+ len = x.len;
+ // Expand array if necessary
+ allocate(len);
+ // Copy number blocks
+ Index i;
+ for (i = 0; i < len; i++)
+ blk[i] = x.blk[i];
+}
+
+template <class Blk>
+NumberlikeArray<Blk>::NumberlikeArray(const Blk *b, Index blen)
+ : cap(blen), len(blen) {
+ // Create array
+ blk = new Blk[cap];
+ // Copy blocks
+ Index i;
+ for (i = 0; i < len; i++)
+ blk[i] = b[i];
+}
+
+template <class Blk>
+bool NumberlikeArray<Blk>::operator ==(const NumberlikeArray<Blk> &x) const {
+ if (len != x.len)
+ // Definitely unequal.
+ return false;
+ else {
+ // Compare corresponding blocks one by one.
+ Index i;
+ for (i = 0; i < len; i++)
+ if (blk[i] != x.blk[i])
+ return false;
+ // No blocks differed, so the objects are equal.
+ return true;
+ }
+}
+
+#endif