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Diffstat (limited to 'src/3rdparty/double-conversion/ieee.h')
-rw-r--r-- | src/3rdparty/double-conversion/ieee.h | 402 |
1 files changed, 0 insertions, 402 deletions
diff --git a/src/3rdparty/double-conversion/ieee.h b/src/3rdparty/double-conversion/ieee.h deleted file mode 100644 index 661141d1a8..0000000000 --- a/src/3rdparty/double-conversion/ieee.h +++ /dev/null @@ -1,402 +0,0 @@ -// Copyright 2012 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. - -#ifndef DOUBLE_CONVERSION_DOUBLE_H_ -#define DOUBLE_CONVERSION_DOUBLE_H_ - -#include "diy-fp.h" - -namespace double_conversion { - -// We assume that doubles and uint64_t have the same endianness. -static uint64_t double_to_uint64(double d) { return BitCast<uint64_t>(d); } -static double uint64_to_double(uint64_t d64) { return BitCast<double>(d64); } -static uint32_t float_to_uint32(float f) { return BitCast<uint32_t>(f); } -static float uint32_to_float(uint32_t d32) { return BitCast<float>(d32); } - -// Helper functions for doubles. -class Double { - public: - static const uint64_t kSignMask = UINT64_2PART_C(0x80000000, 00000000); - static const uint64_t kExponentMask = UINT64_2PART_C(0x7FF00000, 00000000); - static const uint64_t kSignificandMask = UINT64_2PART_C(0x000FFFFF, FFFFFFFF); - static const uint64_t kHiddenBit = UINT64_2PART_C(0x00100000, 00000000); - static const int kPhysicalSignificandSize = 52; // Excludes the hidden bit. - static const int kSignificandSize = 53; - - Double() : d64_(0) {} - explicit Double(double d) : d64_(double_to_uint64(d)) {} - explicit Double(uint64_t d64) : d64_(d64) {} - explicit Double(DiyFp diy_fp) - : d64_(DiyFpToUint64(diy_fp)) {} - - // The value encoded by this Double must be greater or equal to +0.0. - // It must not be special (infinity, or NaN). - DiyFp AsDiyFp() const { - ASSERT(Sign() > 0); - ASSERT(!IsSpecial()); - return DiyFp(Significand(), Exponent()); - } - - // The value encoded by this Double must be strictly greater than 0. - DiyFp AsNormalizedDiyFp() const { - ASSERT(value() > 0.0); - uint64_t f = Significand(); - int e = Exponent(); - - // The current double could be a denormal. - while ((f & kHiddenBit) == 0) { - f <<= 1; - e--; - } - // Do the final shifts in one go. - f <<= DiyFp::kSignificandSize - kSignificandSize; - e -= DiyFp::kSignificandSize - kSignificandSize; - return DiyFp(f, e); - } - - // Returns the double's bit as uint64. - uint64_t AsUint64() const { - return d64_; - } - - // Returns the next greater double. Returns +infinity on input +infinity. - double NextDouble() const { - if (d64_ == kInfinity) return Double(kInfinity).value(); - if (Sign() < 0 && Significand() == 0) { - // -0.0 - return 0.0; - } - if (Sign() < 0) { - return Double(d64_ - 1).value(); - } else { - return Double(d64_ + 1).value(); - } - } - - double PreviousDouble() const { - if (d64_ == (kInfinity | kSignMask)) return -Double::Infinity(); - if (Sign() < 0) { - return Double(d64_ + 1).value(); - } else { - if (Significand() == 0) return -0.0; - return Double(d64_ - 1).value(); - } - } - - int Exponent() const { - if (IsDenormal()) return kDenormalExponent; - - uint64_t d64 = AsUint64(); - int biased_e = - static_cast<int>((d64 & kExponentMask) >> kPhysicalSignificandSize); - return biased_e - kExponentBias; - } - - uint64_t Significand() const { - uint64_t d64 = AsUint64(); - uint64_t significand = d64 & kSignificandMask; - if (!IsDenormal()) { - return significand + kHiddenBit; - } else { - return significand; - } - } - - // Returns true if the double is a denormal. - bool IsDenormal() const { - uint64_t d64 = AsUint64(); - return (d64 & kExponentMask) == 0; - } - - // We consider denormals not to be special. - // Hence only Infinity and NaN are special. - bool IsSpecial() const { - uint64_t d64 = AsUint64(); - return (d64 & kExponentMask) == kExponentMask; - } - - bool IsNan() const { - uint64_t d64 = AsUint64(); - return ((d64 & kExponentMask) == kExponentMask) && - ((d64 & kSignificandMask) != 0); - } - - bool IsInfinite() const { - uint64_t d64 = AsUint64(); - return ((d64 & kExponentMask) == kExponentMask) && - ((d64 & kSignificandMask) == 0); - } - - int Sign() const { - uint64_t d64 = AsUint64(); - return (d64 & kSignMask) == 0? 1: -1; - } - - // Precondition: the value encoded by this Double must be greater or equal - // than +0.0. - DiyFp UpperBoundary() const { - ASSERT(Sign() > 0); - return DiyFp(Significand() * 2 + 1, Exponent() - 1); - } - - // Computes the two boundaries of this. - // The bigger boundary (m_plus) is normalized. The lower boundary has the same - // exponent as m_plus. - // Precondition: the value encoded by this Double must be greater than 0. - void NormalizedBoundaries(DiyFp* out_m_minus, DiyFp* out_m_plus) const { - ASSERT(value() > 0.0); - DiyFp v = this->AsDiyFp(); - DiyFp m_plus = DiyFp::Normalize(DiyFp((v.f() << 1) + 1, v.e() - 1)); - DiyFp m_minus; - if (LowerBoundaryIsCloser()) { - m_minus = DiyFp((v.f() << 2) - 1, v.e() - 2); - } else { - m_minus = DiyFp((v.f() << 1) - 1, v.e() - 1); - } - m_minus.set_f(m_minus.f() << (m_minus.e() - m_plus.e())); - m_minus.set_e(m_plus.e()); - *out_m_plus = m_plus; - *out_m_minus = m_minus; - } - - bool LowerBoundaryIsCloser() const { - // The boundary is closer if the significand is of the form f == 2^p-1 then - // the lower boundary is closer. - // Think of v = 1000e10 and v- = 9999e9. - // Then the boundary (== (v - v-)/2) is not just at a distance of 1e9 but - // at a distance of 1e8. - // The only exception is for the smallest normal: the largest denormal is - // at the same distance as its successor. - // Note: denormals have the same exponent as the smallest normals. - bool physical_significand_is_zero = ((AsUint64() & kSignificandMask) == 0); - return physical_significand_is_zero && (Exponent() != kDenormalExponent); - } - - double value() const { return uint64_to_double(d64_); } - - // Returns the significand size for a given order of magnitude. - // If v = f*2^e with 2^p-1 <= f <= 2^p then p+e is v's order of magnitude. - // This function returns the number of significant binary digits v will have - // once it's encoded into a double. In almost all cases this is equal to - // kSignificandSize. The only exceptions are denormals. They start with - // leading zeroes and their effective significand-size is hence smaller. - static int SignificandSizeForOrderOfMagnitude(int order) { - if (order >= (kDenormalExponent + kSignificandSize)) { - return kSignificandSize; - } - if (order <= kDenormalExponent) return 0; - return order - kDenormalExponent; - } - - static double Infinity() { - return Double(kInfinity).value(); - } - - static double NaN() { - return Double(kNaN).value(); - } - - private: - static const int kExponentBias = 0x3FF + kPhysicalSignificandSize; - static const int kDenormalExponent = -kExponentBias + 1; - static const int kMaxExponent = 0x7FF - kExponentBias; - static const uint64_t kInfinity = UINT64_2PART_C(0x7FF00000, 00000000); - static const uint64_t kNaN = UINT64_2PART_C(0x7FF80000, 00000000); - - const uint64_t d64_; - - static uint64_t DiyFpToUint64(DiyFp diy_fp) { - uint64_t significand = diy_fp.f(); - int exponent = diy_fp.e(); - while (significand > kHiddenBit + kSignificandMask) { - significand >>= 1; - exponent++; - } - if (exponent >= kMaxExponent) { - return kInfinity; - } - if (exponent < kDenormalExponent) { - return 0; - } - while (exponent > kDenormalExponent && (significand & kHiddenBit) == 0) { - significand <<= 1; - exponent--; - } - uint64_t biased_exponent; - if (exponent == kDenormalExponent && (significand & kHiddenBit) == 0) { - biased_exponent = 0; - } else { - biased_exponent = static_cast<uint64_t>(exponent + kExponentBias); - } - return (significand & kSignificandMask) | - (biased_exponent << kPhysicalSignificandSize); - } - - DISALLOW_COPY_AND_ASSIGN(Double); -}; - -class Single { - public: - static const uint32_t kSignMask = 0x80000000; - static const uint32_t kExponentMask = 0x7F800000; - static const uint32_t kSignificandMask = 0x007FFFFF; - static const uint32_t kHiddenBit = 0x00800000; - static const int kPhysicalSignificandSize = 23; // Excludes the hidden bit. - static const int kSignificandSize = 24; - - Single() : d32_(0) {} - explicit Single(float f) : d32_(float_to_uint32(f)) {} - explicit Single(uint32_t d32) : d32_(d32) {} - - // The value encoded by this Single must be greater or equal to +0.0. - // It must not be special (infinity, or NaN). - DiyFp AsDiyFp() const { - ASSERT(Sign() > 0); - ASSERT(!IsSpecial()); - return DiyFp(Significand(), Exponent()); - } - - // Returns the single's bit as uint64. - uint32_t AsUint32() const { - return d32_; - } - - int Exponent() const { - if (IsDenormal()) return kDenormalExponent; - - uint32_t d32 = AsUint32(); - int biased_e = - static_cast<int>((d32 & kExponentMask) >> kPhysicalSignificandSize); - return biased_e - kExponentBias; - } - - uint32_t Significand() const { - uint32_t d32 = AsUint32(); - uint32_t significand = d32 & kSignificandMask; - if (!IsDenormal()) { - return significand + kHiddenBit; - } else { - return significand; - } - } - - // Returns true if the single is a denormal. - bool IsDenormal() const { - uint32_t d32 = AsUint32(); - return (d32 & kExponentMask) == 0; - } - - // We consider denormals not to be special. - // Hence only Infinity and NaN are special. - bool IsSpecial() const { - uint32_t d32 = AsUint32(); - return (d32 & kExponentMask) == kExponentMask; - } - - bool IsNan() const { - uint32_t d32 = AsUint32(); - return ((d32 & kExponentMask) == kExponentMask) && - ((d32 & kSignificandMask) != 0); - } - - bool IsInfinite() const { - uint32_t d32 = AsUint32(); - return ((d32 & kExponentMask) == kExponentMask) && - ((d32 & kSignificandMask) == 0); - } - - int Sign() const { - uint32_t d32 = AsUint32(); - return (d32 & kSignMask) == 0? 1: -1; - } - - // Computes the two boundaries of this. - // The bigger boundary (m_plus) is normalized. The lower boundary has the same - // exponent as m_plus. - // Precondition: the value encoded by this Single must be greater than 0. - void NormalizedBoundaries(DiyFp* out_m_minus, DiyFp* out_m_plus) const { - ASSERT(value() > 0.0); - DiyFp v = this->AsDiyFp(); - DiyFp m_plus = DiyFp::Normalize(DiyFp((v.f() << 1) + 1, v.e() - 1)); - DiyFp m_minus; - if (LowerBoundaryIsCloser()) { - m_minus = DiyFp((v.f() << 2) - 1, v.e() - 2); - } else { - m_minus = DiyFp((v.f() << 1) - 1, v.e() - 1); - } - m_minus.set_f(m_minus.f() << (m_minus.e() - m_plus.e())); - m_minus.set_e(m_plus.e()); - *out_m_plus = m_plus; - *out_m_minus = m_minus; - } - - // Precondition: the value encoded by this Single must be greater or equal - // than +0.0. - DiyFp UpperBoundary() const { - ASSERT(Sign() > 0); - return DiyFp(Significand() * 2 + 1, Exponent() - 1); - } - - bool LowerBoundaryIsCloser() const { - // The boundary is closer if the significand is of the form f == 2^p-1 then - // the lower boundary is closer. - // Think of v = 1000e10 and v- = 9999e9. - // Then the boundary (== (v - v-)/2) is not just at a distance of 1e9 but - // at a distance of 1e8. - // The only exception is for the smallest normal: the largest denormal is - // at the same distance as its successor. - // Note: denormals have the same exponent as the smallest normals. - bool physical_significand_is_zero = ((AsUint32() & kSignificandMask) == 0); - return physical_significand_is_zero && (Exponent() != kDenormalExponent); - } - - float value() const { return uint32_to_float(d32_); } - - static float Infinity() { - return Single(kInfinity).value(); - } - - static float NaN() { - return Single(kNaN).value(); - } - - private: - static const int kExponentBias = 0x7F + kPhysicalSignificandSize; - static const int kDenormalExponent = -kExponentBias + 1; - static const int kMaxExponent = 0xFF - kExponentBias; - static const uint32_t kInfinity = 0x7F800000; - static const uint32_t kNaN = 0x7FC00000; - - const uint32_t d32_; - - DISALLOW_COPY_AND_ASSIGN(Single); -}; - -} // namespace double_conversion - -#endif // DOUBLE_CONVERSION_DOUBLE_H_ |