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-rw-r--r--deps/icu-small/source/i18n/double-conversion-bignum.cpp581
1 files changed, 305 insertions, 276 deletions
diff --git a/deps/icu-small/source/i18n/double-conversion-bignum.cpp b/deps/icu-small/source/i18n/double-conversion-bignum.cpp
index 5356923921..996d75c9f6 100644
--- a/deps/icu-small/source/i18n/double-conversion-bignum.cpp
+++ b/deps/icu-small/source/i18n/double-conversion-bignum.cpp
@@ -34,6 +34,9 @@
#include "unicode/utypes.h"
#if !UCONFIG_NO_FORMATTING
+#include <algorithm>
+#include <cstring>
+
// ICU PATCH: Customize header file paths for ICU.
#include "double-conversion-bignum.h"
@@ -44,136 +47,129 @@ U_NAMESPACE_BEGIN
namespace double_conversion {
-Bignum::Bignum()
- : bigits_buffer_(), bigits_(bigits_buffer_, kBigitCapacity), used_digits_(0), exponent_(0) {
- for (int i = 0; i < kBigitCapacity; ++i) {
- bigits_[i] = 0;
- }
+Bignum::Chunk& Bignum::RawBigit(const int index) {
+ DOUBLE_CONVERSION_ASSERT(static_cast<unsigned>(index) < kBigitCapacity);
+ return bigits_buffer_[index];
+}
+
+
+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) {
- ASSERT(kBigitSize >= BitSize(value));
+void Bignum::AssignUInt16(const uint16_t value) {
+ DOUBLE_CONVERSION_ASSERT(kBigitSize >= BitSize(value));
Zero();
- if (value == 0) return;
-
- EnsureCapacity(1);
- bigits_[0] = value;
- used_digits_ = 1;
+ if (value > 0) {
+ RawBigit(0) = value;
+ used_bigits_ = 1;
+ }
}
void Bignum::AssignUInt64(uint64_t value) {
- const int kUInt64Size = 64;
-
Zero();
- if (value == 0) return;
-
- int needed_bigits = kUInt64Size / kBigitSize + 1;
- EnsureCapacity(needed_bigits);
- for (int i = 0; i < needed_bigits; ++i) {
- bigits_[i] = value & kBigitMask;
- value = value >> kBigitSize;
+ for(int i = 0; value > 0; ++i) {
+ RawBigit(i) = value & kBigitMask;
+ value >>= kBigitSize;
+ ++used_bigits_;
}
- used_digits_ = needed_bigits;
- Clamp();
}
void Bignum::AssignBignum(const Bignum& other) {
exponent_ = other.exponent_;
- for (int i = 0; i < other.used_digits_; ++i) {
- bigits_[i] = other.bigits_[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) {
- bigits_[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';
- ASSERT(0 <= digit && digit <= 9);
+ const int digit = buffer[i] - '0';
+ DOUBLE_CONVERSION_ASSERT(0 <= digit && digit <= 9);
result = result * 10 + digit;
}
return result;
}
-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';
- ASSERT('A' <= c && c <= 'F');
+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;
}
- bigits_[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) {
- bigits_[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);
@@ -181,8 +177,8 @@ void Bignum::AddUInt64(uint64_t operand) {
void Bignum::AddBignum(const Bignum& other) {
- ASSERT(IsClamped());
- ASSERT(other.IsClamped());
+ DOUBLE_CONVERSION_ASSERT(IsClamped());
+ DOUBLE_CONVERSION_ASSERT(other.IsClamped());
// If this has a greater exponent than other append zero-bigits to this.
// After this call exponent_ <= other.exponent_.
@@ -200,48 +196,52 @@ void Bignum::AddBignum(const Bignum& other) {
// cccccccccccc 0000
// In both cases we might need a carry bigit.
- EnsureCapacity(1 + Max(BigitLength(), other.BigitLength()) - exponent_);
+ EnsureCapacity(1 + (std::max)(BigitLength(), other.BigitLength()) - exponent_);
Chunk carry = 0;
int bigit_pos = other.exponent_ - exponent_;
- ASSERT(bigit_pos >= 0);
- for (int i = 0; i < other.used_digits_; ++i) {
- Chunk sum = bigits_[bigit_pos] + other.bigits_[i] + carry;
- bigits_[bigit_pos] = sum & kBigitMask;
+ DOUBLE_CONVERSION_ASSERT(bigit_pos >= 0);
+ 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 = bigits_[bigit_pos] + carry;
- bigits_[bigit_pos] = sum & kBigitMask;
+ 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_ = Max(bigit_pos, used_digits_);
- ASSERT(IsClamped());
+ used_bigits_ = (std::max)(bigit_pos, static_cast<int>(used_bigits_));
+ DOUBLE_CONVERSION_ASSERT(IsClamped());
}
void Bignum::SubtractBignum(const Bignum& other) {
- ASSERT(IsClamped());
- ASSERT(other.IsClamped());
+ DOUBLE_CONVERSION_ASSERT(IsClamped());
+ DOUBLE_CONVERSION_ASSERT(other.IsClamped());
// We require this to be bigger than other.
- ASSERT(LessEqual(other, *this));
+ DOUBLE_CONVERSION_ASSERT(LessEqual(other, *this));
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) {
- ASSERT((borrow == 0) || (borrow == 1));
- Chunk difference = bigits_[i + offset] - other.bigits_[i] - borrow;
- bigits_[i + offset] = difference & kBigitMask;
+ for (i = 0; i < other.used_bigits_; ++i) {
+ DOUBLE_CONVERSION_ASSERT((borrow == 0) || (borrow == 1));
+ const Chunk difference = RawBigit(i + offset) - other.RawBigit(i) - borrow;
+ RawBigit(i + offset) = difference & kBigitMask;
borrow = difference >> (kChunkSize - 1);
}
while (borrow != 0) {
- Chunk difference = bigits_[i + offset] - borrow;
- bigits_[i + offset] = difference & kBigitMask;
+ const Chunk difference = RawBigit(i + offset) - borrow;
+ RawBigit(i + offset) = difference & kBigitMask;
borrow = difference >> (kChunkSize - 1);
++i;
}
@@ -249,91 +249,105 @@ void Bignum::SubtractBignum(const Bignum& other) {
}
-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.
- ASSERT(kDoubleChunkSize >= kBigitSize + 32 + 1);
+ DOUBLE_CONVERSION_ASSERT(kDoubleChunkSize >= kBigitSize + 32 + 1);
DoubleChunk carry = 0;
- for (int i = 0; i < used_digits_; ++i) {
- DoubleChunk product = static_cast<DoubleChunk>(factor) * bigits_[i] + carry;
- bigits_[i] = static_cast<Chunk>(product & kBigitMask);
+ 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);
- bigits_[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;
}
- ASSERT(kBigitSize < 32);
+ 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 * bigits_[i];
- uint64_t product_high = high * bigits_[i];
- uint64_t tmp = (carry & kBigitMask) + product_low;
- bigits_[i] = tmp & kBigitMask;
+ 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);
- bigits_[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 = 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 };
- ASSERT(exponent >= 0);
- if (exponent == 0) return;
- if (used_digits_ == 0) return;
+ DOUBLE_CONVERSION_ASSERT(exponent >= 0);
+ 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) {
@@ -352,8 +366,8 @@ void Bignum::MultiplyByPowerOfTen(int exponent) {
void Bignum::Square() {
- ASSERT(IsClamped());
- int product_length = 2 * used_digits_;
+ DOUBLE_CONVERSION_ASSERT(IsClamped());
+ const int product_length = 2 * used_bigits_;
EnsureCapacity(product_length);
// Comba multiplication: compute each column separately.
@@ -368,64 +382,64 @@ void Bignum::Square() {
//
// 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_) {
- UNIMPLEMENTED();
+ 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) {
- bigits_[copy_offset + i] = bigits_[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 = bigits_[copy_offset + bigit_index1];
- Chunk chunk2 = bigits_[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++;
}
- bigits_[i] = static_cast<Chunk>(accumulator) & kBigitMask;
+ 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 = bigits_[copy_offset + bigit_index1];
- Chunk chunk2 = bigits_[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 bigits_[i] will never be read in further loop iterations,
+ // 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_.
- bigits_[i] = static_cast<Chunk>(accumulator) & kBigitMask;
+ // than i - used_bigits_.
+ RawBigit(i) = static_cast<Chunk>(accumulator) & kBigitMask;
accumulator >>= kBigitSize;
}
// Since the result was guaranteed to lie inside the number the
// accumulator must be 0 now.
- ASSERT(accumulator == 0);
+ 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) {
- ASSERT(base != 0);
- ASSERT(power_exponent >= 0);
+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) {
AssignUInt16(1);
return;
@@ -445,7 +459,7 @@ void Bignum::AssignPowerUInt16(uint16_t base, int power_exponent) {
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);
@@ -466,10 +480,10 @@ void Bignum::AssignPowerUInt16(uint16_t base, int power_exponent) {
// Verify that there is enough space in this_value to perform the
// multiplication. The first bit_size bits must be 0.
if ((power_exponent & mask) != 0) {
- 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;
+ DOUBLE_CONVERSION_ASSERT(bit_size > 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 {
@@ -499,9 +513,9 @@ void Bignum::AssignPowerUInt16(uint16_t base, int power_exponent) {
// Precondition: this/other < 16bit.
uint16_t Bignum::DivideModuloIntBignum(const Bignum& other) {
- ASSERT(IsClamped());
- ASSERT(other.IsClamped());
- ASSERT(other.used_digits_ > 0);
+ DOUBLE_CONVERSION_ASSERT(IsClamped());
+ DOUBLE_CONVERSION_ASSERT(other.IsClamped());
+ 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.
@@ -519,34 +533,34 @@ uint16_t Bignum::DivideModuloIntBignum(const Bignum& other) {
// 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).
- ASSERT(other.bigits_[other.used_digits_ - 1] >= ((1 << kBigitSize) / 16));
- ASSERT(bigits_[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>(bigits_[used_digits_ - 1]);
- SubtractTimes(other, bigits_[used_digits_ - 1]);
+ result += static_cast<uint16_t>(RawBigit(used_bigits_ - 1));
+ SubtractTimes(other, RawBigit(used_bigits_ - 1));
}
- ASSERT(BigitLength() == other.BigitLength());
+ 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
- // bigits_[used_digits_ - 1] is safe.
- Chunk this_bigit = bigits_[used_digits_ - 1];
- Chunk other_bigit = other.bigits_[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;
- bigits_[used_digits_ - 1] = this_bigit - other_bigit * quotient;
- ASSERT(quotient < 0x10000);
+ 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);
- ASSERT(division_estimate < 0x10000);
+ 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);
@@ -566,7 +580,7 @@ uint16_t Bignum::DivideModuloIntBignum(const Bignum& other) {
template<typename S>
static int SizeInHexChars(S number) {
- ASSERT(number > 0);
+ DOUBLE_CONVERSION_ASSERT(number > 0);
int result = 0;
while (number != 0) {
number >>= 4;
@@ -576,29 +590,35 @@ static int SizeInHexChars(S number) {
}
-static char HexCharOfValue(int value) {
- ASSERT(0 <= value && value <= 16);
- if (value < 10) return static_cast<char>(value + '0');
+static char HexCharOfValue(const int value) {
+ DOUBLE_CONVERSION_ASSERT(0 <= value && value <= 16);
+ 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 {
- ASSERT(IsClamped());
+bool Bignum::ToHexString(char* buffer, const int buffer_size) const {
+ DOUBLE_CONVERSION_ASSERT(IsClamped());
// Each bigit must be printable as separate hex-character.
- ASSERT(kBigitSize % 4 == 0);
- const int kHexCharsPerBigit = kBigitSize / 4;
+ DOUBLE_CONVERSION_ASSERT(kBigitSize % 4 == 0);
+ 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(bigits_[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) {
@@ -606,15 +626,15 @@ bool Bignum::ToHexString(char* buffer, int buffer_size) const {
buffer[string_index--] = '0';
}
}
- for (int i = 0; i < used_digits_ - 1; ++i) {
- Chunk current_bigit = bigits_[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);
current_bigit >>= 4;
}
}
// And finally the last bigit.
- Chunk most_significant_bigit = bigits_[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;
@@ -623,25 +643,37 @@ bool Bignum::ToHexString(char* buffer, int buffer_size) const {
}
-Bignum::Chunk Bignum::BigitAt(int index) const {
- if (index >= BigitLength()) return 0;
- if (index < exponent_) return 0;
- return bigits_[index - exponent_];
+Bignum::Chunk Bignum::BigitOrZero(const int index) const {
+ if (index >= BigitLength()) {
+ return 0;
+ }
+ if (index < exponent_) {
+ return 0;
+ }
+ return RawBigit(index - exponent_);
}
int Bignum::Compare(const Bignum& a, const Bignum& b) {
- ASSERT(a.IsClamped());
- 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;
- for (int i = bigit_length_a - 1; i >= Min(a.exponent_, b.exponent_); --i) {
- Chunk bigit_a = a.BigitAt(i);
- Chunk bigit_b = b.BigitAt(i);
- if (bigit_a < bigit_b) return -1;
- if (bigit_a > bigit_b) return +1;
+ DOUBLE_CONVERSION_ASSERT(a.IsClamped());
+ DOUBLE_CONVERSION_ASSERT(b.IsClamped());
+ 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) {
+ 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;
@@ -649,14 +681,18 @@ int Bignum::Compare(const Bignum& a, const Bignum& b) {
int Bignum::PlusCompare(const Bignum& a, const Bignum& b, const Bignum& c) {
- ASSERT(a.IsClamped());
- ASSERT(b.IsClamped());
- ASSERT(c.IsClamped());
+ DOUBLE_CONVERSION_ASSERT(a.IsClamped());
+ DOUBLE_CONVERSION_ASSERT(b.IsClamped());
+ DOUBLE_CONVERSION_ASSERT(c.IsClamped());
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'.
@@ -666,92 +702,83 @@ int Bignum::PlusCompare(const Bignum& a, const Bignum& b, const Bignum& c) {
Chunk borrow = 0;
// Starting at min_exponent all digits are == 0. So no need to compare them.
- int min_exponent = Min(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.BigitAt(i);
- Chunk chunk_b = b.BigitAt(i);
- Chunk chunk_c = c.BigitAt(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 && bigits_[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 || bigits_[used_digits_ - 1] != 0;
-}
-
-
-void Bignum::Zero() {
- for (int i = 0; i < used_digits_; ++i) {
- bigits_[i] = 0;
- }
- 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) {
- bigits_[i + zero_digits] = bigits_[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) {
- bigits_[i] = 0;
+ for (int i = 0; i < zero_bigits; ++i) {
+ RawBigit(i) = 0;
}
- used_digits_ += zero_digits;
- exponent_ -= zero_digits;
- ASSERT(used_digits_ >= 0);
- ASSERT(exponent_ >= 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) {
- ASSERT(shift_amount < kBigitSize);
- ASSERT(shift_amount >= 0);
+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 = bigits_[i] >> (kBigitSize - shift_amount);
- bigits_[i] = ((bigits_[i] << shift_amount) + carry) & kBigitMask;
+ 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) {
- bigits_[used_digits_] = carry;
- used_digits_++;
+ RawBigit(used_bigits_) = carry;
+ used_bigits_++;
}
}
-void Bignum::SubtractTimes(const Bignum& other, int factor) {
- ASSERT(exponent_ <= other.exponent_);
+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) {
SubtractBignum(other);
@@ -759,19 +786,21 @@ void Bignum::SubtractTimes(const Bignum& other, int factor) {
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.bigits_[i];
- DoubleChunk remove = borrow + product;
- Chunk difference = bigits_[i + exponent_diff] - (remove & kBigitMask);
- bigits_[i + exponent_diff] = difference & 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 = bigits_[i] - borrow;
- bigits_[i] = difference & kBigitMask;
+ 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);
}
Clamp();
generated by cgit v1.2.3 (git 2.39.1) at 2024-04-26 20:01:37 +0000