Move Source/WTF/wtf to Source/wtf

Source/WTF/wtf/dtoa/diy-fp.h

-// 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 WTF {
-
-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 are not designed to contain special doubles (NaN and Infinity).
-    class DiyFp {
-    public:
-        static const int kSignificandSize = 64;
-        
-        DiyFp() : f_(0), e_(0) {}
-        DiyFp(uint64_t f, int e) : f_(f), e_(e) {}
-        
-        // this = this - other.
-        // The exponents of both numbers must be the same and the significand of this
-        // must be bigger than the significand of other.
-        // The result will not be normalized.
-        void Subtract(const DiyFp& other) {
-            ASSERT(e_ == other.e_);
-            ASSERT(f_ >= other.f_);
-            f_ -= other.f_;
-        }
-        
-        // Returns a - b.
-        // The exponents of both numbers must be the same and this must be bigger
-        // than other. The result will not be normalized.
-        static DiyFp Minus(const DiyFp& a, const DiyFp& b) {
-            DiyFp result = a;
-            result.Subtract(b);
-            return result;
-        }
-        
-        
-        // this = this * other.
-        void Multiply(const DiyFp& other);
-        
-        // returns a * b;
-        static DiyFp Times(const DiyFp& a, const DiyFp& b) {
-            DiyFp result = a;
-            result.Multiply(b);
-            return result;
-        }
-        
-        void Normalize() {
-            ASSERT(f_ != 0);
-            uint64_t f = f_;
-            int e = e_;
-            
-            // This method is mainly called for normalizing boundaries. In general
-            // boundaries need to be shifted by 10 bits. We thus optimize for this case.
-            const uint64_t k10MSBits = UINT64_2PART_C(0xFFC00000, 00000000);
-            while ((f & k10MSBits) == 0) {
-                f <<= 10;
-                e -= 10;
-            }
-            while ((f & kUint64MSB) == 0) {
-                f <<= 1;
-                e--;
-            }
-            f_ = f;
-            e_ = e;
-        }
-        
-        static DiyFp Normalize(const DiyFp& a) {
-            DiyFp result = a;
-            result.Normalize();
-            return result;
-        }
-        
-        uint64_t f() const { return f_; }
-        int e() const { return e_; }
-        
-        void set_f(uint64_t new_value) { f_ = new_value; }
-        void set_e(int new_value) { e_ = new_value; }
-        
-    private:
-        static const uint64_t kUint64MSB = UINT64_2PART_C(0x80000000, 00000000);
-        
-        uint64_t f_;
-        int e_;
-    };
-    
-}  // namespace double_conversion
-
-} // namespace WTF
-
-#endif  // DOUBLE_CONVERSION_DIY_FP_H_