Index: runtime/third_party/double-conversion/src/double.h |
=================================================================== |
--- runtime/third_party/double-conversion/src/double.h (revision 33139) |
+++ runtime/third_party/double-conversion/src/double.h (working copy) |
@@ -1,245 +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. |
- |
-#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); } |
- |
-// 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(); |
- } |
- } |
- |
- 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(); |
- bool significand_is_zero = (v.f() == kHiddenBit); |
- DiyFp m_plus = DiyFp::Normalize(DiyFp((v.f() << 1) + 1, v.e() - 1)); |
- DiyFp m_minus; |
- if (significand_is_zero && v.e() != kDenormalExponent) { |
- // The 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. |
- 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; |
- } |
- |
- 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); |
- } |
-}; |
- |
-} // namespace double_conversion |
- |
-#endif // DOUBLE_CONVERSION_DOUBLE_H_ |