diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 17:32:43 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 17:32:43 +0000 |
commit | 6bf0a5cb5034a7e684dcc3500e841785237ce2dd (patch) | |
tree | a68f146d7fa01f0134297619fbe7e33db084e0aa /security/sandbox/chromium/base/third_party/double_conversion/double-conversion/diy-fp.h | |
parent | Initial commit. (diff) | |
download | thunderbird-upstream.tar.xz thunderbird-upstream.zip |
Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'security/sandbox/chromium/base/third_party/double_conversion/double-conversion/diy-fp.h')
-rw-r--r-- | security/sandbox/chromium/base/third_party/double_conversion/double-conversion/diy-fp.h | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/security/sandbox/chromium/base/third_party/double_conversion/double-conversion/diy-fp.h b/security/sandbox/chromium/base/third_party/double_conversion/double-conversion/diy-fp.h new file mode 100644 index 0000000000..a2200c4ded --- /dev/null +++ b/security/sandbox/chromium/base/third_party/double_conversion/double-conversion/diy-fp.h @@ -0,0 +1,137 @@ +// 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_DIY_FP_H_ +#define DOUBLE_CONVERSION_DIY_FP_H_ + +#include "utils.h" + +namespace double_conversion { + +// This "Do It Yourself Floating Point" class implements a floating-point number +// 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 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(const uint64_t significand, const int32_t exponent) : f_(significand), e_(exponent) {} + + // this -= other. + // The exponents of both numbers must be the same and the significand of this + // 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_); + DOUBLE_CONVERSION_ASSERT(f_ >= other.f_); + f_ -= other.f_; + } + + // Returns a - b. + // 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 *= 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) { + DiyFp result = a; + result.Multiply(b); + return result; + } + + void Normalize() { + DOUBLE_CONVERSION_ASSERT(f_ != 0); + uint64_t significand = f_; + int32_t exponent = e_; + + // 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; + exponent -= 10; + } + while ((significand & kUint64MSB) == 0) { + significand <<= 1; + exponent--; + } + f_ = significand; + e_ = exponent; + } + + static DiyFp Normalize(const DiyFp& a) { + DiyFp result = a; + result.Normalize(); + return result; + } + + uint64_t f() const { return f_; } + int32_t e() const { return e_; } + + void set_f(uint64_t new_value) { f_ = 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_; + int32_t e_; +}; + +} // namespace double_conversion + +#endif // DOUBLE_CONVERSION_DIY_FP_H_ |