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Diffstat (limited to 'deps/v8/src/double.h')
-rw-r--r-- | deps/v8/src/double.h | 169 |
1 files changed, 0 insertions, 169 deletions
diff --git a/deps/v8/src/double.h b/deps/v8/src/double.h deleted file mode 100644 index f3d17b93f9..0000000000 --- a/deps/v8/src/double.h +++ /dev/null @@ -1,169 +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 V8_DOUBLE_H_ -#define V8_DOUBLE_H_ - -#include "diy_fp.h" - -namespace v8 { -namespace internal { - -// 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 = V8_2PART_UINT64_C(0x80000000, 00000000); - static const uint64_t kExponentMask = V8_2PART_UINT64_C(0x7FF00000, 00000000); - static const uint64_t kSignificandMask = - V8_2PART_UINT64_C(0x000FFFFF, FFFFFFFF); - static const uint64_t kHiddenBit = V8_2PART_UINT64_C(0x00100000, 00000000); - - Double() : d64_(0) {} - explicit Double(double d) : d64_(double_to_uint64(d)) {} - explicit Double(uint64_t d64) : d64_(d64) {} - - DiyFp AsDiyFp() const { - ASSERT(!IsSpecial()); - return DiyFp(Significand(), Exponent()); - } - - // this->Significand() must not be 0. - DiyFp AsNormalizedDiyFp() const { - uint64_t f = Significand(); - int e = Exponent(); - - ASSERT(f != 0); - - // The current double could be a denormal. - while ((f & kHiddenBit) == 0) { - f <<= 1; - e--; - } - // Do the final shifts in one go. Don't forget the hidden bit (the '-1'). - f <<= DiyFp::kSignificandSize - kSignificandSize - 1; - e -= DiyFp::kSignificandSize - kSignificandSize - 1; - return DiyFp(f, e); - } - - // Returns the double's bit as uint64. - uint64_t AsUint64() const { - return d64_; - } - - int Exponent() const { - if (IsDenormal()) return kDenormalExponent; - - uint64_t d64 = AsUint64(); - int biased_e = static_cast<int>((d64 & kExponentMask) >> kSignificandSize); - 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; - } - - - // Returns the two boundaries of this. - // The bigger boundary (m_plus) is normalized. The lower boundary has the same - // exponent as m_plus. - void NormalizedBoundaries(DiyFp* out_m_minus, DiyFp* out_m_plus) const { - 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_); } - - private: - static const int kSignificandSize = 52; // Excludes the hidden bit. - static const int kExponentBias = 0x3FF + kSignificandSize; - static const int kDenormalExponent = -kExponentBias + 1; - - uint64_t d64_; -}; - -} } // namespace v8::internal - -#endif // V8_DOUBLE_H_ |