More Bignum fiddling. (#108)
* Char has size 1.
* More const.
* Allow inlining.
* Compact Bignum sizes.
* Consistent naming.
diff --git a/.gitignore b/.gitignore
index cbe3c57..1438a3b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,5 @@
.sconsign.dblite
+*~
*.o
*.obj
msvc/Release/
@@ -10,6 +11,7 @@
*.a
*.so
*.so.*
+*.dylib
/run_tests
Makefile
CMakeLists.txt.user
diff --git a/README.md b/README.md
index 4ae9be5..7b9869e 100644
--- a/README.md
+++ b/README.md
@@ -7,8 +7,9 @@
from the V8 JavaScript engine. The code has been refactored and improved so that
it can be used more easily in other projects.
-There is extensive documentation in `double-conversion/double-conversion.h`. Other
-examples can be found in `test/cctest/test-conversions.cc`.
+There is extensive documentation in `double-conversion/string-to-double.h` and
+`double-conversion/double-to-string.h`. Other examples can be found in
+`test/cctest/test-conversions.cc`.
Building
diff --git a/double-conversion/SConscript b/double-conversion/SConscript
index f6d4da7..d7ae3d7 100644
--- a/double-conversion/SConscript
+++ b/double-conversion/SConscript
@@ -3,7 +3,6 @@
'bignum.cc',
'bignum-dtoa.cc',
'cached-powers.cc',
- 'diy-fp.cc',
'double-to-string.cc',
'fast-dtoa.cc',
'fixed-dtoa.cc',
diff --git a/double-conversion/bignum.cc b/double-conversion/bignum.cc
index f089715..d858c16 100644
--- a/double-conversion/bignum.cc
+++ b/double-conversion/bignum.cc
@@ -33,80 +33,60 @@
namespace double_conversion {
-Bignum::Bignum()
- : used_digits_(0), exponent_(0) {
- std::memset(bigits_buffer_, 0, sizeof(Chunk) * kBigitCapacity);
-}
-
-
-Bignum::Chunk& Bignum::RawBigit(int index) {
+Bignum::Chunk& Bignum::RawBigit(const int index) {
DOUBLE_CONVERSION_ASSERT(static_cast<unsigned>(index) < kBigitCapacity);
return bigits_buffer_[index];
}
-const Bignum::Chunk& Bignum::RawBigit(int index) const {
+const Bignum::Chunk& Bignum::RawBigit(const int index) const {
DOUBLE_CONVERSION_ASSERT(static_cast<unsigned>(index) < kBigitCapacity);
return bigits_buffer_[index];
}
template<typename S>
-static int BitSize(S value) {
+static int BitSize(const S value) {
(void) value; // Mark variable as used.
return 8 * sizeof(value);
}
// Guaranteed to lie in one Bigit.
-void Bignum::AssignUInt16(uint16_t value) {
+void Bignum::AssignUInt16(const uint16_t value) {
DOUBLE_CONVERSION_ASSERT(kBigitSize >= BitSize(value));
Zero();
- if (value == 0) {
- return;
+ if (value > 0) {
+ RawBigit(0) = value;
+ used_bigits_ = 1;
}
- EnsureCapacity(1);
- RawBigit(0) = value;
- used_digits_ = 1;
}
void Bignum::AssignUInt64(uint64_t value) {
- const int kUInt64Size = 64;
-
Zero();
- if (value == 0) {
- return;
+ for(int i = 0; value > 0; ++i) {
+ RawBigit(i) = value & kBigitMask;
+ value >>= kBigitSize;
+ ++used_bigits_;
}
- int needed_bigits = kUInt64Size / kBigitSize + 1;
- EnsureCapacity(needed_bigits);
- for (int i = 0; i < needed_bigits; ++i) {
- RawBigit(i) = value & kBigitMask;
- value = value >> kBigitSize;
- }
- used_digits_ = needed_bigits;
- Clamp();
}
void Bignum::AssignBignum(const Bignum& other) {
exponent_ = other.exponent_;
- for (int i = 0; i < other.used_digits_; ++i) {
+ for (int i = 0; i < other.used_bigits_; ++i) {
RawBigit(i) = other.RawBigit(i);
}
- // Clear the excess digits (if there were any).
- for (int i = other.used_digits_; i < used_digits_; ++i) {
- RawBigit(i) = 0;
- }
- used_digits_ = other.used_digits_;
+ used_bigits_ = other.used_bigits_;
}
-static uint64_t ReadUInt64(Vector<const char> buffer,
- int from,
- int digits_to_read) {
+static uint64_t ReadUInt64(const Vector<const char> buffer,
+ const int from,
+ const int digits_to_read) {
uint64_t result = 0;
for (int i = from; i < from + digits_to_read; ++i) {
- int digit = buffer[i] - '0';
+ const int digit = buffer[i] - '0';
DOUBLE_CONVERSION_ASSERT(0 <= digit && digit <= 9);
result = result * 10 + digit;
}
@@ -114,67 +94,68 @@
}
-void Bignum::AssignDecimalString(Vector<const char> value) {
+void Bignum::AssignDecimalString(const Vector<const char> value) {
// 2^64 = 18446744073709551616 > 10^19
- const int kMaxUint64DecimalDigits = 19;
+ static const int kMaxUint64DecimalDigits = 19;
Zero();
int length = value.length();
- unsigned int pos = 0;
+ unsigned pos = 0;
// Let's just say that each digit needs 4 bits.
while (length >= kMaxUint64DecimalDigits) {
- uint64_t digits = ReadUInt64(value, pos, kMaxUint64DecimalDigits);
+ const uint64_t digits = ReadUInt64(value, pos, kMaxUint64DecimalDigits);
pos += kMaxUint64DecimalDigits;
length -= kMaxUint64DecimalDigits;
MultiplyByPowerOfTen(kMaxUint64DecimalDigits);
AddUInt64(digits);
}
- uint64_t digits = ReadUInt64(value, pos, length);
+ const uint64_t digits = ReadUInt64(value, pos, length);
MultiplyByPowerOfTen(length);
AddUInt64(digits);
Clamp();
}
-static int HexCharValue(char c) {
- if ('0' <= c && c <= '9') return c - '0';
- if ('a' <= c && c <= 'f') return 10 + c - 'a';
+static uint64_t HexCharValue(const int c) {
+ if ('0' <= c && c <= '9') {
+ return c - '0';
+ }
+ if ('a' <= c && c <= 'f') {
+ return 10 + c - 'a';
+ }
DOUBLE_CONVERSION_ASSERT('A' <= c && c <= 'F');
return 10 + c - 'A';
}
+// Unlike AssignDecimalString(), this function is "only" used
+// for unit-tests and therefore not performance critical.
void Bignum::AssignHexString(Vector<const char> value) {
Zero();
- int length = value.length();
-
- int needed_bigits = length * 4 / kBigitSize + 1;
- EnsureCapacity(needed_bigits);
- int string_index = length - 1;
- for (int i = 0; i < needed_bigits - 1; ++i) {
- // These bigits are guaranteed to be "full".
- Chunk current_bigit = 0;
- for (int j = 0; j < kBigitSize / 4; j++) {
- current_bigit += HexCharValue(value[string_index--]) << (j * 4);
+ // Required capacity could be reduced by ignoring leading zeros.
+ EnsureCapacity(((value.length() * 4) + kBigitSize - 1) / kBigitSize);
+ DOUBLE_CONVERSION_ASSERT(sizeof(uint64_t) * 8 >= kBigitSize + 4); // TODO: static_assert
+ // Accumulates converted hex digits until at least kBigitSize bits.
+ // Works with non-factor-of-four kBigitSizes.
+ uint64_t tmp = 0; // Accumulates converted hex digits until at least
+ for (int cnt = 0; !value.is_empty(); value.pop_back()) {
+ tmp |= (HexCharValue(value.last()) << cnt);
+ if ((cnt += 4) >= kBigitSize) {
+ RawBigit(used_bigits_++) = (tmp & kBigitMask);
+ cnt -= kBigitSize;
+ tmp >>= kBigitSize;
}
- RawBigit(i) = current_bigit;
}
- used_digits_ = needed_bigits - 1;
-
- Chunk most_significant_bigit = 0; // Could be = 0;
- for (int j = 0; j <= string_index; ++j) {
- most_significant_bigit <<= 4;
- most_significant_bigit += HexCharValue(value[j]);
- }
- if (most_significant_bigit != 0) {
- RawBigit(used_digits_) = most_significant_bigit;
- used_digits_++;
+ if (tmp > 0) {
+ RawBigit(used_bigits_++) = tmp;
}
Clamp();
}
-void Bignum::AddUInt64(uint64_t operand) {
- if (operand == 0) return;
+void Bignum::AddUInt64(const uint64_t operand) {
+ if (operand == 0) {
+ return;
+ }
Bignum other;
other.AssignUInt64(operand);
AddBignum(other);
@@ -205,20 +186,24 @@
Chunk carry = 0;
int bigit_pos = other.exponent_ - exponent_;
DOUBLE_CONVERSION_ASSERT(bigit_pos >= 0);
- for (int i = 0; i < other.used_digits_; ++i) {
- Chunk sum = RawBigit(bigit_pos) + other.RawBigit(i) + carry;
+ for (int i = used_bigits_; i < bigit_pos; ++i) {
+ RawBigit(i) = 0;
+ }
+ for (int i = 0; i < other.used_bigits_; ++i) {
+ const Chunk my = (bigit_pos < used_bigits_) ? RawBigit(bigit_pos) : 0;
+ const Chunk sum = my + other.RawBigit(i) + carry;
RawBigit(bigit_pos) = sum & kBigitMask;
carry = sum >> kBigitSize;
- bigit_pos++;
+ ++bigit_pos;
}
-
while (carry != 0) {
- Chunk sum = RawBigit(bigit_pos) + carry;
+ const Chunk my = (bigit_pos < used_bigits_) ? RawBigit(bigit_pos) : 0;
+ const Chunk sum = my + carry;
RawBigit(bigit_pos) = sum & kBigitMask;
carry = sum >> kBigitSize;
- bigit_pos++;
+ ++bigit_pos;
}
- used_digits_ = (std::max)(bigit_pos, used_digits_);
+ used_bigits_ = (std::max)(bigit_pos, static_cast<int>(used_bigits_));
DOUBLE_CONVERSION_ASSERT(IsClamped());
}
@@ -231,17 +216,17 @@
Align(other);
- int offset = other.exponent_ - exponent_;
+ const int offset = other.exponent_ - exponent_;
Chunk borrow = 0;
int i;
- for (i = 0; i < other.used_digits_; ++i) {
+ for (i = 0; i < other.used_bigits_; ++i) {
DOUBLE_CONVERSION_ASSERT((borrow == 0) || (borrow == 1));
- Chunk difference = RawBigit(i + offset) - other.RawBigit(i) - borrow;
+ const Chunk difference = RawBigit(i + offset) - other.RawBigit(i) - borrow;
RawBigit(i + offset) = difference & kBigitMask;
borrow = difference >> (kChunkSize - 1);
}
while (borrow != 0) {
- Chunk difference = RawBigit(i + offset) - borrow;
+ const Chunk difference = RawBigit(i + offset) - borrow;
RawBigit(i + offset) = difference & kBigitMask;
borrow = difference >> (kChunkSize - 1);
++i;
@@ -250,91 +235,105 @@
}
-void Bignum::ShiftLeft(int shift_amount) {
- if (used_digits_ == 0) return;
- exponent_ += shift_amount / kBigitSize;
- int local_shift = shift_amount % kBigitSize;
- EnsureCapacity(used_digits_ + 1);
+void Bignum::ShiftLeft(const int shift_amount) {
+ if (used_bigits_ == 0) {
+ return;
+ }
+ exponent_ += (shift_amount / kBigitSize);
+ const int local_shift = shift_amount % kBigitSize;
+ EnsureCapacity(used_bigits_ + 1);
BigitsShiftLeft(local_shift);
}
-void Bignum::MultiplyByUInt32(uint32_t factor) {
- if (factor == 1) return;
+void Bignum::MultiplyByUInt32(const uint32_t factor) {
+ if (factor == 1) {
+ return;
+ }
if (factor == 0) {
Zero();
return;
}
- if (used_digits_ == 0) return;
-
+ if (used_bigits_ == 0) {
+ return;
+ }
// The product of a bigit with the factor is of size kBigitSize + 32.
// Assert that this number + 1 (for the carry) fits into double chunk.
DOUBLE_CONVERSION_ASSERT(kDoubleChunkSize >= kBigitSize + 32 + 1);
DoubleChunk carry = 0;
- for (int i = 0; i < used_digits_; ++i) {
- DoubleChunk product = static_cast<DoubleChunk>(factor) * RawBigit(i) + carry;
+ for (int i = 0; i < used_bigits_; ++i) {
+ const DoubleChunk product = static_cast<DoubleChunk>(factor) * RawBigit(i) + carry;
RawBigit(i) = static_cast<Chunk>(product & kBigitMask);
carry = (product >> kBigitSize);
}
while (carry != 0) {
- EnsureCapacity(used_digits_ + 1);
- RawBigit(used_digits_) = carry & kBigitMask;
- used_digits_++;
+ EnsureCapacity(used_bigits_ + 1);
+ RawBigit(used_bigits_) = carry & kBigitMask;
+ used_bigits_++;
carry >>= kBigitSize;
}
}
-void Bignum::MultiplyByUInt64(uint64_t factor) {
- if (factor == 1) return;
+void Bignum::MultiplyByUInt64(const uint64_t factor) {
+ if (factor == 1) {
+ return;
+ }
if (factor == 0) {
Zero();
return;
}
+ if (used_bigits_ == 0) {
+ return;
+ }
DOUBLE_CONVERSION_ASSERT(kBigitSize < 32);
uint64_t carry = 0;
- uint64_t low = factor & 0xFFFFFFFF;
- uint64_t high = factor >> 32;
- for (int i = 0; i < used_digits_; ++i) {
- uint64_t product_low = low * RawBigit(i);
- uint64_t product_high = high * RawBigit(i);
- uint64_t tmp = (carry & kBigitMask) + product_low;
+ const uint64_t low = factor & 0xFFFFFFFF;
+ const uint64_t high = factor >> 32;
+ for (int i = 0; i < used_bigits_; ++i) {
+ const uint64_t product_low = low * RawBigit(i);
+ const uint64_t product_high = high * RawBigit(i);
+ const uint64_t tmp = (carry & kBigitMask) + product_low;
RawBigit(i) = tmp & kBigitMask;
carry = (carry >> kBigitSize) + (tmp >> kBigitSize) +
(product_high << (32 - kBigitSize));
}
while (carry != 0) {
- EnsureCapacity(used_digits_ + 1);
- RawBigit(used_digits_) = carry & kBigitMask;
- used_digits_++;
+ EnsureCapacity(used_bigits_ + 1);
+ RawBigit(used_bigits_) = carry & kBigitMask;
+ used_bigits_++;
carry >>= kBigitSize;
}
}
-void Bignum::MultiplyByPowerOfTen(int exponent) {
- const uint64_t kFive27 = DOUBLE_CONVERSION_UINT64_2PART_C(0x6765c793, fa10079d);
- const uint16_t kFive1 = 5;
- const uint16_t kFive2 = kFive1 * 5;
- const uint16_t kFive3 = kFive2 * 5;
- const uint16_t kFive4 = kFive3 * 5;
- const uint16_t kFive5 = kFive4 * 5;
- const uint16_t kFive6 = kFive5 * 5;
- const uint32_t kFive7 = kFive6 * 5;
- const uint32_t kFive8 = kFive7 * 5;
- const uint32_t kFive9 = kFive8 * 5;
- const uint32_t kFive10 = kFive9 * 5;
- const uint32_t kFive11 = kFive10 * 5;
- const uint32_t kFive12 = kFive11 * 5;
- const uint32_t kFive13 = kFive12 * 5;
- const uint32_t kFive1_to_12[] =
+void Bignum::MultiplyByPowerOfTen(const int exponent) {
+ static const uint64_t kFive27 = DOUBLE_CONVERSION_UINT64_2PART_C(0x6765c793, fa10079d);
+ static const uint16_t kFive1 = 5;
+ static const uint16_t kFive2 = kFive1 * 5;
+ static const uint16_t kFive3 = kFive2 * 5;
+ static const uint16_t kFive4 = kFive3 * 5;
+ static const uint16_t kFive5 = kFive4 * 5;
+ static const uint16_t kFive6 = kFive5 * 5;
+ static const uint32_t kFive7 = kFive6 * 5;
+ static const uint32_t kFive8 = kFive7 * 5;
+ static const uint32_t kFive9 = kFive8 * 5;
+ static const uint32_t kFive10 = kFive9 * 5;
+ static const uint32_t kFive11 = kFive10 * 5;
+ static const uint32_t kFive12 = kFive11 * 5;
+ static const uint32_t kFive13 = kFive12 * 5;
+ static const uint32_t kFive1_to_12[] =
{ kFive1, kFive2, kFive3, kFive4, kFive5, kFive6,
kFive7, kFive8, kFive9, kFive10, kFive11, kFive12 };
DOUBLE_CONVERSION_ASSERT(exponent >= 0);
- if (exponent == 0) return;
- if (used_digits_ == 0) return;
+ if (exponent == 0) {
+ return;
+ }
+ if (used_bigits_ == 0) {
+ return;
+ }
// We shift by exponent at the end just before returning.
int remaining_exponent = exponent;
while (remaining_exponent >= 27) {
@@ -354,7 +353,7 @@
void Bignum::Square() {
DOUBLE_CONVERSION_ASSERT(IsClamped());
- int product_length = 2 * used_digits_;
+ const int product_length = 2 * used_bigits_;
EnsureCapacity(product_length);
// Comba multiplication: compute each column separately.
@@ -369,25 +368,25 @@
//
// Assert that the additional number of bits in a DoubleChunk are enough to
// sum up used_digits of Bigit*Bigit.
- if ((1 << (2 * (kChunkSize - kBigitSize))) <= used_digits_) {
+ if ((1 << (2 * (kChunkSize - kBigitSize))) <= used_bigits_) {
DOUBLE_CONVERSION_UNIMPLEMENTED();
}
DoubleChunk accumulator = 0;
// First shift the digits so we don't overwrite them.
- int copy_offset = used_digits_;
- for (int i = 0; i < used_digits_; ++i) {
+ const int copy_offset = used_bigits_;
+ for (int i = 0; i < used_bigits_; ++i) {
RawBigit(copy_offset + i) = RawBigit(i);
}
// We have two loops to avoid some 'if's in the loop.
- for (int i = 0; i < used_digits_; ++i) {
+ for (int i = 0; i < used_bigits_; ++i) {
// Process temporary digit i with power i.
// The sum of the two indices must be equal to i.
int bigit_index1 = i;
int bigit_index2 = 0;
// Sum all of the sub-products.
while (bigit_index1 >= 0) {
- Chunk chunk1 = RawBigit(copy_offset + bigit_index1);
- Chunk chunk2 = RawBigit(copy_offset + bigit_index2);
+ const Chunk chunk1 = RawBigit(copy_offset + bigit_index1);
+ const Chunk chunk2 = RawBigit(copy_offset + bigit_index2);
accumulator += static_cast<DoubleChunk>(chunk1) * chunk2;
bigit_index1--;
bigit_index2++;
@@ -395,21 +394,21 @@
RawBigit(i) = static_cast<Chunk>(accumulator) & kBigitMask;
accumulator >>= kBigitSize;
}
- for (int i = used_digits_; i < product_length; ++i) {
- int bigit_index1 = used_digits_ - 1;
+ for (int i = used_bigits_; i < product_length; ++i) {
+ int bigit_index1 = used_bigits_ - 1;
int bigit_index2 = i - bigit_index1;
// Invariant: sum of both indices is again equal to i.
// Inner loop runs 0 times on last iteration, emptying accumulator.
- while (bigit_index2 < used_digits_) {
- Chunk chunk1 = RawBigit(copy_offset + bigit_index1);
- Chunk chunk2 = RawBigit(copy_offset + bigit_index2);
+ while (bigit_index2 < used_bigits_) {
+ const Chunk chunk1 = RawBigit(copy_offset + bigit_index1);
+ const Chunk chunk2 = RawBigit(copy_offset + bigit_index2);
accumulator += static_cast<DoubleChunk>(chunk1) * chunk2;
bigit_index1--;
bigit_index2++;
}
// The overwritten RawBigit(i) will never be read in further loop iterations,
// because bigit_index1 and bigit_index2 are always greater
- // than i - used_digits_.
+ // than i - used_bigits_.
RawBigit(i) = static_cast<Chunk>(accumulator) & kBigitMask;
accumulator >>= kBigitSize;
}
@@ -418,13 +417,13 @@
DOUBLE_CONVERSION_ASSERT(accumulator == 0);
// Don't forget to update the used_digits and the exponent.
- used_digits_ = product_length;
+ used_bigits_ = product_length;
exponent_ *= 2;
Clamp();
}
-void Bignum::AssignPowerUInt16(uint16_t base, int power_exponent) {
+void Bignum::AssignPowerUInt16(uint16_t base, const int power_exponent) {
DOUBLE_CONVERSION_ASSERT(base != 0);
DOUBLE_CONVERSION_ASSERT(power_exponent >= 0);
if (power_exponent == 0) {
@@ -446,7 +445,7 @@
tmp_base >>= 1;
bit_size++;
}
- int final_size = bit_size * power_exponent;
+ const int final_size = bit_size * power_exponent;
// 1 extra bigit for the shifting, and one for rounded final_size.
EnsureCapacity(final_size / kBigitSize + 2);
@@ -468,9 +467,9 @@
// multiplication. The first bit_size bits must be 0.
if ((power_exponent & mask) != 0) {
DOUBLE_CONVERSION_ASSERT(bit_size > 0);
- uint64_t base_bits_mask =
- ~((static_cast<uint64_t>(1) << (64 - bit_size)) - 1);
- bool high_bits_zero = (this_value & base_bits_mask) == 0;
+ const uint64_t base_bits_mask =
+ ~((static_cast<uint64_t>(1) << (64 - bit_size)) - 1);
+ const bool high_bits_zero = (this_value & base_bits_mask) == 0;
if (high_bits_zero) {
this_value *= base;
} else {
@@ -502,7 +501,7 @@
uint16_t Bignum::DivideModuloIntBignum(const Bignum& other) {
DOUBLE_CONVERSION_ASSERT(IsClamped());
DOUBLE_CONVERSION_ASSERT(other.IsClamped());
- DOUBLE_CONVERSION_ASSERT(other.used_digits_ > 0);
+ DOUBLE_CONVERSION_ASSERT(other.used_bigits_ > 0);
// Easy case: if we have less digits than the divisor than the result is 0.
// Note: this handles the case where this == 0, too.
@@ -520,33 +519,33 @@
// This naive approach is extremely inefficient if `this` divided by other
// is big. This function is implemented for doubleToString where
// the result should be small (less than 10).
- DOUBLE_CONVERSION_ASSERT(other.RawBigit(other.used_digits_ - 1) >= ((1 << kBigitSize) / 16));
- DOUBLE_CONVERSION_ASSERT(RawBigit(used_digits_ - 1) < 0x10000);
+ DOUBLE_CONVERSION_ASSERT(other.RawBigit(other.used_bigits_ - 1) >= ((1 << kBigitSize) / 16));
+ DOUBLE_CONVERSION_ASSERT(RawBigit(used_bigits_ - 1) < 0x10000);
// Remove the multiples of the first digit.
// Example this = 23 and other equals 9. -> Remove 2 multiples.
- result += static_cast<uint16_t>(RawBigit(used_digits_ - 1));
- SubtractTimes(other, RawBigit(used_digits_ - 1));
+ result += static_cast<uint16_t>(RawBigit(used_bigits_ - 1));
+ SubtractTimes(other, RawBigit(used_bigits_ - 1));
}
DOUBLE_CONVERSION_ASSERT(BigitLength() == other.BigitLength());
// Both bignums are at the same length now.
// Since other has more than 0 digits we know that the access to
- // RawBigit(used_digits_ - 1) is safe.
- Chunk this_bigit = RawBigit(used_digits_ - 1);
- Chunk other_bigit = other.RawBigit(other.used_digits_ - 1);
+ // RawBigit(used_bigits_ - 1) is safe.
+ const Chunk this_bigit = RawBigit(used_bigits_ - 1);
+ const Chunk other_bigit = other.RawBigit(other.used_bigits_ - 1);
- if (other.used_digits_ == 1) {
+ if (other.used_bigits_ == 1) {
// Shortcut for easy (and common) case.
int quotient = this_bigit / other_bigit;
- RawBigit(used_digits_ - 1) = this_bigit - other_bigit * quotient;
+ RawBigit(used_bigits_ - 1) = this_bigit - other_bigit * quotient;
DOUBLE_CONVERSION_ASSERT(quotient < 0x10000);
result += static_cast<uint16_t>(quotient);
Clamp();
return result;
}
- int division_estimate = this_bigit / (other_bigit + 1);
+ const int division_estimate = this_bigit / (other_bigit + 1);
DOUBLE_CONVERSION_ASSERT(division_estimate < 0x10000);
result += static_cast<uint16_t>(division_estimate);
SubtractTimes(other, division_estimate);
@@ -577,29 +576,35 @@
}
-static char HexCharOfValue(int value) {
+static char HexCharOfValue(const int value) {
DOUBLE_CONVERSION_ASSERT(0 <= value && value <= 16);
- if (value < 10) return static_cast<char>(value + '0');
+ if (value < 10) {
+ return static_cast<char>(value + '0');
+ }
return static_cast<char>(value - 10 + 'A');
}
-bool Bignum::ToHexString(char* buffer, int buffer_size) const {
+bool Bignum::ToHexString(char* buffer, const int buffer_size) const {
DOUBLE_CONVERSION_ASSERT(IsClamped());
// Each bigit must be printable as separate hex-character.
DOUBLE_CONVERSION_ASSERT(kBigitSize % 4 == 0);
- const int kHexCharsPerBigit = kBigitSize / 4;
+ static const int kHexCharsPerBigit = kBigitSize / 4;
- if (used_digits_ == 0) {
- if (buffer_size < 2) return false;
+ if (used_bigits_ == 0) {
+ if (buffer_size < 2) {
+ return false;
+ }
buffer[0] = '0';
buffer[1] = '\0';
return true;
}
// We add 1 for the terminating '\0' character.
- int needed_chars = (BigitLength() - 1) * kHexCharsPerBigit +
- SizeInHexChars(RawBigit(used_digits_ - 1)) + 1;
- if (needed_chars > buffer_size) return false;
+ const int needed_chars = (BigitLength() - 1) * kHexCharsPerBigit +
+ SizeInHexChars(RawBigit(used_bigits_ - 1)) + 1;
+ if (needed_chars > buffer_size) {
+ return false;
+ }
int string_index = needed_chars - 1;
buffer[string_index--] = '\0';
for (int i = 0; i < exponent_; ++i) {
@@ -607,7 +612,7 @@
buffer[string_index--] = '0';
}
}
- for (int i = 0; i < used_digits_ - 1; ++i) {
+ for (int i = 0; i < used_bigits_ - 1; ++i) {
Chunk current_bigit = RawBigit(i);
for (int j = 0; j < kHexCharsPerBigit; ++j) {
buffer[string_index--] = HexCharOfValue(current_bigit & 0xF);
@@ -615,7 +620,7 @@
}
}
// And finally the last bigit.
- Chunk most_significant_bigit = RawBigit(used_digits_ - 1);
+ Chunk most_significant_bigit = RawBigit(used_bigits_ - 1);
while (most_significant_bigit != 0) {
buffer[string_index--] = HexCharOfValue(most_significant_bigit & 0xF);
most_significant_bigit >>= 4;
@@ -624,9 +629,13 @@
}
-Bignum::Chunk Bignum::BigitOrZero(int index) const {
- if (index >= BigitLength()) return 0;
- if (index < exponent_) return 0;
+Bignum::Chunk Bignum::BigitOrZero(const int index) const {
+ if (index >= BigitLength()) {
+ return 0;
+ }
+ if (index < exponent_) {
+ return 0;
+ }
return RawBigit(index - exponent_);
}
@@ -634,15 +643,23 @@
int Bignum::Compare(const Bignum& a, const Bignum& b) {
DOUBLE_CONVERSION_ASSERT(a.IsClamped());
DOUBLE_CONVERSION_ASSERT(b.IsClamped());
- int bigit_length_a = a.BigitLength();
- int bigit_length_b = b.BigitLength();
- if (bigit_length_a < bigit_length_b) return -1;
- if (bigit_length_a > bigit_length_b) return +1;
+ const int bigit_length_a = a.BigitLength();
+ const int bigit_length_b = b.BigitLength();
+ if (bigit_length_a < bigit_length_b) {
+ return -1;
+ }
+ if (bigit_length_a > bigit_length_b) {
+ return +1;
+ }
for (int i = bigit_length_a - 1; i >= (std::min)(a.exponent_, b.exponent_); --i) {
- Chunk bigit_a = a.BigitOrZero(i);
- Chunk bigit_b = b.BigitOrZero(i);
- if (bigit_a < bigit_b) return -1;
- if (bigit_a > bigit_b) return +1;
+ const Chunk bigit_a = a.BigitOrZero(i);
+ const Chunk bigit_b = b.BigitOrZero(i);
+ if (bigit_a < bigit_b) {
+ return -1;
+ }
+ if (bigit_a > bigit_b) {
+ return +1;
+ }
// Otherwise they are equal up to this digit. Try the next digit.
}
return 0;
@@ -656,8 +673,12 @@
if (a.BigitLength() < b.BigitLength()) {
return PlusCompare(b, a, c);
}
- if (a.BigitLength() + 1 < c.BigitLength()) return -1;
- if (a.BigitLength() > c.BigitLength()) return +1;
+ if (a.BigitLength() + 1 < c.BigitLength()) {
+ return -1;
+ }
+ if (a.BigitLength() > c.BigitLength()) {
+ return +1;
+ }
// The exponent encodes 0-bigits. So if there are more 0-digits in 'a' than
// 'b' has digits, then the bigit-length of 'a'+'b' must be equal to the one
// of 'a'.
@@ -667,89 +688,82 @@
Chunk borrow = 0;
// Starting at min_exponent all digits are == 0. So no need to compare them.
- int min_exponent = (std::min)((std::min)(a.exponent_, b.exponent_), c.exponent_);
+ const int min_exponent = (std::min)((std::min)(a.exponent_, b.exponent_), c.exponent_);
for (int i = c.BigitLength() - 1; i >= min_exponent; --i) {
- Chunk chunk_a = a.BigitOrZero(i);
- Chunk chunk_b = b.BigitOrZero(i);
- Chunk chunk_c = c.BigitOrZero(i);
- Chunk sum = chunk_a + chunk_b;
+ const Chunk chunk_a = a.BigitOrZero(i);
+ const Chunk chunk_b = b.BigitOrZero(i);
+ const Chunk chunk_c = c.BigitOrZero(i);
+ const Chunk sum = chunk_a + chunk_b;
if (sum > chunk_c + borrow) {
return +1;
} else {
borrow = chunk_c + borrow - sum;
- if (borrow > 1) return -1;
+ if (borrow > 1) {
+ return -1;
+ }
borrow <<= kBigitSize;
}
}
- if (borrow == 0) return 0;
+ if (borrow == 0) {
+ return 0;
+ }
return -1;
}
void Bignum::Clamp() {
- while (used_digits_ > 0 && RawBigit(used_digits_ - 1) == 0) {
- used_digits_--;
+ while (used_bigits_ > 0 && RawBigit(used_bigits_ - 1) == 0) {
+ used_bigits_--;
}
- if (used_digits_ == 0) {
+ if (used_bigits_ == 0) {
// Zero.
exponent_ = 0;
}
}
-bool Bignum::IsClamped() const {
- return used_digits_ == 0 || RawBigit(used_digits_ - 1) != 0;
-}
-
-
-void Bignum::Zero() {
- std::memset(bigits_buffer_, 0, sizeof(Chunk) * used_digits_);
- used_digits_ = 0;
- exponent_ = 0;
-}
-
-
void Bignum::Align(const Bignum& other) {
if (exponent_ > other.exponent_) {
- // If "X" represents a "hidden" digit (by the exponent) then we are in the
+ // If "X" represents a "hidden" bigit (by the exponent) then we are in the
// following case (a == this, b == other):
// a: aaaaaaXXXX or a: aaaaaXXX
// b: bbbbbbX b: bbbbbbbbXX
// We replace some of the hidden digits (X) of a with 0 digits.
// a: aaaaaa000X or a: aaaaa0XX
- int zero_digits = exponent_ - other.exponent_;
- EnsureCapacity(used_digits_ + zero_digits);
- for (int i = used_digits_ - 1; i >= 0; --i) {
- RawBigit(i + zero_digits) = RawBigit(i);
+ const int zero_bigits = exponent_ - other.exponent_;
+ EnsureCapacity(used_bigits_ + zero_bigits);
+ for (int i = used_bigits_ - 1; i >= 0; --i) {
+ RawBigit(i + zero_bigits) = RawBigit(i);
}
- for (int i = 0; i < zero_digits; ++i) {
+ for (int i = 0; i < zero_bigits; ++i) {
RawBigit(i) = 0;
}
- used_digits_ += zero_digits;
- exponent_ -= zero_digits;
- DOUBLE_CONVERSION_ASSERT(used_digits_ >= 0);
+ used_bigits_ += zero_bigits;
+ exponent_ -= zero_bigits;
+
+ DOUBLE_CONVERSION_ASSERT(used_bigits_ >= 0);
DOUBLE_CONVERSION_ASSERT(exponent_ >= 0);
}
}
-void Bignum::BigitsShiftLeft(int shift_amount) {
+void Bignum::BigitsShiftLeft(const int shift_amount) {
DOUBLE_CONVERSION_ASSERT(shift_amount < kBigitSize);
DOUBLE_CONVERSION_ASSERT(shift_amount >= 0);
Chunk carry = 0;
- for (int i = 0; i < used_digits_; ++i) {
- Chunk new_carry = RawBigit(i) >> (kBigitSize - shift_amount);
+ for (int i = 0; i < used_bigits_; ++i) {
+ const Chunk new_carry = RawBigit(i) >> (kBigitSize - shift_amount);
RawBigit(i) = ((RawBigit(i) << shift_amount) + carry) & kBigitMask;
carry = new_carry;
}
if (carry != 0) {
- RawBigit(used_digits_) = carry;
- used_digits_++;
+ RawBigit(used_bigits_) = carry;
+ used_bigits_++;
}
}
-void Bignum::SubtractTimes(const Bignum& other, int factor) {
+void Bignum::SubtractTimes(const Bignum& other, const int factor) {
DOUBLE_CONVERSION_ASSERT(exponent_ <= other.exponent_);
if (factor < 3) {
for (int i = 0; i < factor; ++i) {
@@ -758,18 +772,20 @@
return;
}
Chunk borrow = 0;
- int exponent_diff = other.exponent_ - exponent_;
- for (int i = 0; i < other.used_digits_; ++i) {
- DoubleChunk product = static_cast<DoubleChunk>(factor) * other.RawBigit(i);
- DoubleChunk remove = borrow + product;
- Chunk difference = RawBigit(i + exponent_diff) - (remove & kBigitMask);
+ const int exponent_diff = other.exponent_ - exponent_;
+ for (int i = 0; i < other.used_bigits_; ++i) {
+ const DoubleChunk product = static_cast<DoubleChunk>(factor) * other.RawBigit(i);
+ const DoubleChunk remove = borrow + product;
+ const Chunk difference = RawBigit(i + exponent_diff) - (remove & kBigitMask);
RawBigit(i + exponent_diff) = difference & kBigitMask;
borrow = static_cast<Chunk>((difference >> (kChunkSize - 1)) +
(remove >> kBigitSize));
}
- for (int i = other.used_digits_ + exponent_diff; i < used_digits_; ++i) {
- if (borrow == 0) return;
- Chunk difference = RawBigit(i) - borrow;
+ for (int i = other.used_bigits_ + exponent_diff; i < used_bigits_; ++i) {
+ if (borrow == 0) {
+ return;
+ }
+ const Chunk difference = RawBigit(i) - borrow;
RawBigit(i) = difference & kBigitMask;
borrow = difference >> (kChunkSize - 1);
}
diff --git a/double-conversion/bignum.h b/double-conversion/bignum.h
index d42532f..14d1ca8 100644
--- a/double-conversion/bignum.h
+++ b/double-conversion/bignum.h
@@ -39,26 +39,27 @@
// exponent.
static const int kMaxSignificantBits = 3584;
- Bignum();
- void AssignUInt16(uint16_t value);
+ Bignum() : used_bigits_(0), exponent_(0) {}
+
+ void AssignUInt16(const uint16_t value);
void AssignUInt64(uint64_t value);
void AssignBignum(const Bignum& other);
- void AssignDecimalString(Vector<const char> value);
- void AssignHexString(Vector<const char> value);
+ void AssignDecimalString(const Vector<const char> value);
+ void AssignHexString(const Vector<const char> value);
- void AssignPowerUInt16(uint16_t base, int exponent);
+ void AssignPowerUInt16(uint16_t base, const int exponent);
- void AddUInt64(uint64_t operand);
+ void AddUInt64(const uint64_t operand);
void AddBignum(const Bignum& other);
// Precondition: this >= other.
void SubtractBignum(const Bignum& other);
void Square();
- void ShiftLeft(int shift_amount);
- void MultiplyByUInt32(uint32_t factor);
- void MultiplyByUInt64(uint64_t factor);
- void MultiplyByPowerOfTen(int exponent);
+ void ShiftLeft(const int shift_amount);
+ void MultiplyByUInt32(const uint32_t factor);
+ void MultiplyByUInt64(const uint64_t factor);
+ void MultiplyByPowerOfTen(const int exponent);
void Times10() { return MultiplyByUInt32(10); }
// Pseudocode:
// int result = this / other;
@@ -66,7 +67,7 @@
// In the worst case this function is in O(this/other).
uint16_t DivideModuloIntBignum(const Bignum& other);
- bool ToHexString(char* buffer, int buffer_size) const;
+ bool ToHexString(char* buffer, const int buffer_size) const;
// Returns
// -1 if a < b,
@@ -110,29 +111,37 @@
// grow. There are no checks if the stack-allocated space is sufficient.
static const int kBigitCapacity = kMaxSignificantBits / kBigitSize;
- void EnsureCapacity(int size) {
+ static void EnsureCapacity(const int size) {
if (size > kBigitCapacity) {
DOUBLE_CONVERSION_UNREACHABLE();
}
}
void Align(const Bignum& other);
void Clamp();
- bool IsClamped() const;
- void Zero();
+ bool IsClamped() const {
+ return used_bigits_ == 0 || RawBigit(used_bigits_ - 1) != 0;
+ }
+ void Zero() {
+ used_bigits_ = 0;
+ exponent_ = 0;
+ }
// Requires this to have enough capacity (no tests done).
- // Updates used_digits_ if necessary.
+ // Updates used_bigits_ if necessary.
// shift_amount must be < kBigitSize.
- void BigitsShiftLeft(int shift_amount);
- // BigitLength includes the "hidden" digits encoded in the exponent.
- int BigitLength() const { return used_digits_ + exponent_; }
- Chunk& RawBigit(int index);
- const Chunk& RawBigit(int index) const;
- Chunk BigitOrZero(int index) const;
- void SubtractTimes(const Bignum& other, int factor);
+ void BigitsShiftLeft(const int shift_amount);
+ // BigitLength includes the "hidden" bigits encoded in the exponent.
+ int BigitLength() const { return used_bigits_ + exponent_; }
+ Chunk& RawBigit(const int index);
+ const Chunk& RawBigit(const int index) const;
+ Chunk BigitOrZero(const int index) const;
+ void SubtractTimes(const Bignum& other, const int factor);
- int used_digits_;
- // The Bignum's value equals value(bigits_) * 2^(exponent_ * kBigitSize).
- int exponent_;
+ // The Bignum's value is value(bigits_buffer_) * 2^(exponent_ * kBigitSize),
+ // where the value of the buffer consists of the lower kBigitSize bits of
+ // the first used_bigits_ Chunks in bigits_buffer_, first chunk has lowest
+ // significant bits.
+ int16_t used_bigits_;
+ int16_t exponent_;
Chunk bigits_buffer_[kBigitCapacity];
DOUBLE_CONVERSION_DISALLOW_COPY_AND_ASSIGN(Bignum);
diff --git a/double-conversion/cached-powers.cc b/double-conversion/cached-powers.cc
index c0eef77..56bdfc9 100644
--- a/double-conversion/cached-powers.cc
+++ b/double-conversion/cached-powers.cc
@@ -35,6 +35,8 @@
namespace double_conversion {
+namespace PowersOfTenCache {
+
struct CachedPower {
uint64_t significand;
int16_t binary_exponent;
@@ -133,12 +135,8 @@
static const int kCachedPowersOffset = 348; // -1 * the first decimal_exponent.
static const double kD_1_LOG2_10 = 0.30102999566398114; // 1 / lg(10)
-// Difference between the decimal exponents in the table above.
-const int PowersOfTenCache::kDecimalExponentDistance = 8;
-const int PowersOfTenCache::kMinDecimalExponent = -348;
-const int PowersOfTenCache::kMaxDecimalExponent = 340;
-void PowersOfTenCache::GetCachedPowerForBinaryExponentRange(
+void GetCachedPowerForBinaryExponentRange(
int min_exponent,
int max_exponent,
DiyFp* power,
@@ -158,9 +156,9 @@
}
-void PowersOfTenCache::GetCachedPowerForDecimalExponent(int requested_exponent,
- DiyFp* power,
- int* found_exponent) {
+void GetCachedPowerForDecimalExponent(int requested_exponent,
+ DiyFp* power,
+ int* found_exponent) {
DOUBLE_CONVERSION_ASSERT(kMinDecimalExponent <= requested_exponent);
DOUBLE_CONVERSION_ASSERT(requested_exponent < kMaxDecimalExponent + kDecimalExponentDistance);
int index =
@@ -172,4 +170,6 @@
DOUBLE_CONVERSION_ASSERT(requested_exponent < *found_exponent + kDecimalExponentDistance);
}
+} // namespace PowersOfTenCache
+
} // namespace double_conversion
diff --git a/double-conversion/cached-powers.h b/double-conversion/cached-powers.h
index 61a5061..f38c26d 100644
--- a/double-conversion/cached-powers.h
+++ b/double-conversion/cached-powers.h
@@ -32,32 +32,32 @@
namespace double_conversion {
-class PowersOfTenCache {
- public:
+namespace PowersOfTenCache {
// Not all powers of ten are cached. The decimal exponent of two neighboring
// cached numbers will differ by kDecimalExponentDistance.
- static const int kDecimalExponentDistance;
+ static const int kDecimalExponentDistance = 8;
- static const int kMinDecimalExponent;
- static const int kMaxDecimalExponent;
+ static const int kMinDecimalExponent = -348;
+ static const int kMaxDecimalExponent = 340;
// Returns a cached power-of-ten with a binary exponent in the range
// [min_exponent; max_exponent] (boundaries included).
- static void GetCachedPowerForBinaryExponentRange(int min_exponent,
- int max_exponent,
- DiyFp* power,
- int* decimal_exponent);
+ void GetCachedPowerForBinaryExponentRange(int min_exponent,
+ int max_exponent,
+ DiyFp* power,
+ int* decimal_exponent);
// Returns a cached power of ten x ~= 10^k such that
// k <= decimal_exponent < k + kCachedPowersDecimalDistance.
// The given decimal_exponent must satisfy
// kMinDecimalExponent <= requested_exponent, and
// requested_exponent < kMaxDecimalExponent + kDecimalExponentDistance.
- static void GetCachedPowerForDecimalExponent(int requested_exponent,
- DiyFp* power,
- int* found_exponent);
-};
+ void GetCachedPowerForDecimalExponent(int requested_exponent,
+ DiyFp* power,
+ int* found_exponent);
+
+} // namespace PowersOfTenCache
} // namespace double_conversion
diff --git a/double-conversion/diy-fp.cc b/double-conversion/diy-fp.cc
deleted file mode 100644
index ddd1891..0000000
--- a/double-conversion/diy-fp.cc
+++ /dev/null
@@ -1,57 +0,0 @@
-// Copyright 2010 the V8 project authors. All rights reserved.
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-// * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-// * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following
-// disclaimer in the documentation and/or other materials provided
-// with the distribution.
-// * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived
-// from this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-
-#include "diy-fp.h"
-#include "utils.h"
-
-namespace double_conversion {
-
-void DiyFp::Multiply(const DiyFp& other) {
- // Simply "emulates" a 128 bit multiplication.
- // However: the resulting number only contains 64 bits. The least
- // significant 64 bits are only used for rounding the most significant 64
- // bits.
- const uint64_t kM32 = 0xFFFFFFFFU;
- uint64_t a = f_ >> 32;
- uint64_t b = f_ & kM32;
- uint64_t c = other.f_ >> 32;
- uint64_t d = other.f_ & kM32;
- uint64_t ac = a * c;
- uint64_t bc = b * c;
- uint64_t ad = a * d;
- uint64_t bd = b * d;
- uint64_t tmp = (bd >> 32) + (ad & kM32) + (bc & kM32);
- // By adding 1U << 31 to tmp we round the final result.
- // Halfway cases will be round up.
- tmp += 1U << 31;
- uint64_t result_f = ac + (ad >> 32) + (bc >> 32) + (tmp >> 32);
- e_ += other.e_ + 64;
- f_ = result_f;
-}
-
-} // namespace double_conversion
diff --git a/double-conversion/diy-fp.h b/double-conversion/diy-fp.h
index 2e1ae2c..a2200c4 100644
--- a/double-conversion/diy-fp.h
+++ b/double-conversion/diy-fp.h
@@ -36,17 +36,18 @@
// with a uint64 significand and an int exponent. Normalized DiyFp numbers will
// have the most significant bit of the significand set.
// Multiplication and Subtraction do not normalize their results.
-// DiyFp are not designed to contain special doubles (NaN and Infinity).
+// DiyFp store only non-negative numbers and are not designed to contain special
+// doubles (NaN and Infinity).
class DiyFp {
public:
static const int kSignificandSize = 64;
DiyFp() : f_(0), e_(0) {}
- DiyFp(uint64_t significand, int exponent) : f_(significand), e_(exponent) {}
+ DiyFp(const uint64_t significand, const int32_t exponent) : f_(significand), e_(exponent) {}
- // this = this - other.
+ // this -= other.
// The exponents of both numbers must be the same and the significand of this
- // must be bigger than the significand of other.
+ // must be greater or equal than the significand of other.
// The result will not be normalized.
void Subtract(const DiyFp& other) {
DOUBLE_CONVERSION_ASSERT(e_ == other.e_);
@@ -55,17 +56,35 @@
}
// Returns a - b.
- // The exponents of both numbers must be the same and this must be bigger
- // than other. The result will not be normalized.
+ // The exponents of both numbers must be the same and a must be greater
+ // or equal than b. The result will not be normalized.
static DiyFp Minus(const DiyFp& a, const DiyFp& b) {
DiyFp result = a;
result.Subtract(b);
return result;
}
-
- // this = this * other.
- void Multiply(const DiyFp& other);
+ // this *= other.
+ void Multiply(const DiyFp& other) {
+ // Simply "emulates" a 128 bit multiplication.
+ // However: the resulting number only contains 64 bits. The least
+ // significant 64 bits are only used for rounding the most significant 64
+ // bits.
+ const uint64_t kM32 = 0xFFFFFFFFU;
+ const uint64_t a = f_ >> 32;
+ const uint64_t b = f_ & kM32;
+ const uint64_t c = other.f_ >> 32;
+ const uint64_t d = other.f_ & kM32;
+ const uint64_t ac = a * c;
+ const uint64_t bc = b * c;
+ const uint64_t ad = a * d;
+ const uint64_t bd = b * d;
+ // By adding 1U << 31 to tmp we round the final result.
+ // Halfway cases will be rounded up.
+ const uint64_t tmp = (bd >> 32) + (ad & kM32) + (bc & kM32) + (1U << 31);
+ e_ += other.e_ + 64;
+ f_ = ac + (ad >> 32) + (bc >> 32) + (tmp >> 32);
+ }
// returns a * b;
static DiyFp Times(const DiyFp& a, const DiyFp& b) {
@@ -77,10 +96,10 @@
void Normalize() {
DOUBLE_CONVERSION_ASSERT(f_ != 0);
uint64_t significand = f_;
- int exponent = e_;
+ int32_t exponent = e_;
- // This method is mainly called for normalizing boundaries. In general
- // boundaries need to be shifted by 10 bits. We thus optimize for this case.
+ // This method is mainly called for normalizing boundaries. In general,
+ // boundaries need to be shifted by 10 bits, and we optimize for this case.
const uint64_t k10MSBits = DOUBLE_CONVERSION_UINT64_2PART_C(0xFFC00000, 00000000);
while ((significand & k10MSBits) == 0) {
significand <<= 10;
@@ -101,16 +120,16 @@
}
uint64_t f() const { return f_; }
- int e() const { return e_; }
+ int32_t e() const { return e_; }
void set_f(uint64_t new_value) { f_ = new_value; }
- void set_e(int new_value) { e_ = new_value; }
+ void set_e(int32_t new_value) { e_ = new_value; }
private:
static const uint64_t kUint64MSB = DOUBLE_CONVERSION_UINT64_2PART_C(0x80000000, 00000000);
uint64_t f_;
- int e_;
+ int32_t e_;
};
} // namespace double_conversion
diff --git a/double-conversion/utils.h b/double-conversion/utils.h
index 3a4d587..a66289e 100644
--- a/double-conversion/utils.h
+++ b/double-conversion/utils.h
@@ -176,8 +176,6 @@
namespace double_conversion {
-static const int kCharSize = sizeof(char);
-
inline int StrLength(const char* string) {
size_t length = strlen(string);
DOUBLE_CONVERSION_ASSERT(length == static_cast<size_t>(static_cast<int>(length)));
@@ -221,6 +219,11 @@
T& last() { return start_[length_ - 1]; }
+ void pop_back() {
+ DOUBLE_CONVERSION_ASSERT(!is_empty());
+ --length_;
+ }
+
private:
T* start_;
int length_;
@@ -268,7 +271,7 @@
void AddSubstring(const char* s, int n) {
DOUBLE_CONVERSION_ASSERT(!is_finalized() && position_ + n < buffer_.length());
DOUBLE_CONVERSION_ASSERT(static_cast<size_t>(n) <= strlen(s));
- memmove(&buffer_[position_], s, n * kCharSize);
+ memmove(&buffer_[position_], s, n);
position_ += n;
}
@@ -327,7 +330,7 @@
// enough that it can no longer see that you have cast one pointer type to
// another thus avoiding the warning.
template <class Dest, class Source>
-inline Dest BitCast(const Source& source) {
+Dest BitCast(const Source& source) {
// Compile time assertion: sizeof(Dest) == sizeof(Source)
// A compile error here means your Dest and Source have different sizes.
#if __cplusplus >= 201103L
@@ -344,7 +347,7 @@
}
template <class Dest, class Source>
-inline Dest BitCast(Source* source) {
+Dest BitCast(Source* source) {
return BitCast<Dest>(reinterpret_cast<uintptr_t>(source));
}
diff --git a/test/cctest/test-bignum.cc b/test/cctest/test-bignum.cc
index 0653b27..1bf6a69 100644
--- a/test/cctest/test-bignum.cc
+++ b/test/cctest/test-bignum.cc
@@ -314,9 +314,13 @@
CHECK_EQ("10000000000001000000000000", buffer);
other.ShiftLeft(64);
- // other == "10000000000000000000000000000"
+ CHECK(other.ToHexString(buffer, kBufferSize));
+ CHECK_EQ("10000000000000000000000000000", buffer);
bignum.AssignUInt16(0x1);
+ CHECK(bignum.ToHexString(buffer, kBufferSize));
+ CHECK_EQ("1", buffer);
+
bignum.AddBignum(other);
CHECK(bignum.ToHexString(buffer, kBufferSize));
CHECK_EQ("10000000000000000000000000001", buffer);
