/src/icu/source/i18n/double-conversion-ieee.h
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1  |  | // © 2018 and later: Unicode, Inc. and others.  | 
2  |  | // License & terms of use: http://www.unicode.org/copyright.html  | 
3  |  | //  | 
4  |  | // From the double-conversion library. Original license:  | 
5  |  | //  | 
6  |  | // Copyright 2012 the V8 project authors. All rights reserved.  | 
7  |  | // Redistribution and use in source and binary forms, with or without  | 
8  |  | // modification, are permitted provided that the following conditions are  | 
9  |  | // met:  | 
10  |  | //  | 
11  |  | //     * Redistributions of source code must retain the above copyright  | 
12  |  | //       notice, this list of conditions and the following disclaimer.  | 
13  |  | //     * Redistributions in binary form must reproduce the above  | 
14  |  | //       copyright notice, this list of conditions and the following  | 
15  |  | //       disclaimer in the documentation and/or other materials provided  | 
16  |  | //       with the distribution.  | 
17  |  | //     * Neither the name of Google Inc. nor the names of its  | 
18  |  | //       contributors may be used to endorse or promote products derived  | 
19  |  | //       from this software without specific prior written permission.  | 
20  |  | //  | 
21  |  | // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS  | 
22  |  | // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT  | 
23  |  | // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR  | 
24  |  | // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT  | 
25  |  | // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,  | 
26  |  | // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT  | 
27  |  | // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,  | 
28  |  | // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY  | 
29  |  | // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT  | 
30  |  | // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE  | 
31  |  | // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.  | 
32  |  |  | 
33  |  | // ICU PATCH: ifdef around UCONFIG_NO_FORMATTING  | 
34  |  | #include "unicode/utypes.h"  | 
35  |  | #if !UCONFIG_NO_FORMATTING  | 
36  |  |  | 
37  |  | #ifndef DOUBLE_CONVERSION_DOUBLE_H_  | 
38  |  | #define DOUBLE_CONVERSION_DOUBLE_H_  | 
39  |  |  | 
40  |  | // ICU PATCH: Customize header file paths for ICU.  | 
41  |  |  | 
42  |  | #include "double-conversion-diy-fp.h"  | 
43  |  |  | 
44  |  | // ICU PATCH: Wrap in ICU namespace  | 
45  |  | U_NAMESPACE_BEGIN  | 
46  |  |  | 
47  |  | namespace double_conversion { | 
48  |  |  | 
49  |  | // We assume that doubles and uint64_t have the same endianness.  | 
50  | 0  | static uint64_t double_to_uint64(double d) { return BitCast<uint64_t>(d); }Unexecuted instantiation: double-conversion-double-to-string.cpp:icu_70::double_conversion::double_to_uint64(double) Unexecuted instantiation: double-conversion-fast-dtoa.cpp:icu_70::double_conversion::double_to_uint64(double) Unexecuted instantiation: double-conversion-string-to-double.cpp:icu_70::double_conversion::double_to_uint64(double) Unexecuted instantiation: double-conversion-strtod.cpp:icu_70::double_conversion::double_to_uint64(double) Unexecuted instantiation: double-conversion-bignum-dtoa.cpp:icu_70::double_conversion::double_to_uint64(double)  | 
51  | 0  | static double uint64_to_double(uint64_t d64) { return BitCast<double>(d64); }Unexecuted instantiation: double-conversion-double-to-string.cpp:icu_70::double_conversion::uint64_to_double(unsigned long) Unexecuted instantiation: double-conversion-fast-dtoa.cpp:icu_70::double_conversion::uint64_to_double(unsigned long) Unexecuted instantiation: double-conversion-string-to-double.cpp:icu_70::double_conversion::uint64_to_double(unsigned long) Unexecuted instantiation: double-conversion-strtod.cpp:icu_70::double_conversion::uint64_to_double(unsigned long) Unexecuted instantiation: double-conversion-bignum-dtoa.cpp:icu_70::double_conversion::uint64_to_double(unsigned long)  | 
52  | 0  | static uint32_t float_to_uint32(float f) { return BitCast<uint32_t>(f); }Unexecuted instantiation: double-conversion-double-to-string.cpp:icu_70::double_conversion::float_to_uint32(float) Unexecuted instantiation: double-conversion-fast-dtoa.cpp:icu_70::double_conversion::float_to_uint32(float) Unexecuted instantiation: double-conversion-string-to-double.cpp:icu_70::double_conversion::float_to_uint32(float) Unexecuted instantiation: double-conversion-strtod.cpp:icu_70::double_conversion::float_to_uint32(float) Unexecuted instantiation: double-conversion-bignum-dtoa.cpp:icu_70::double_conversion::float_to_uint32(float)  | 
53  | 0  | static float uint32_to_float(uint32_t d32) { return BitCast<float>(d32); }Unexecuted instantiation: double-conversion-double-to-string.cpp:icu_70::double_conversion::uint32_to_float(unsigned int) Unexecuted instantiation: double-conversion-fast-dtoa.cpp:icu_70::double_conversion::uint32_to_float(unsigned int) Unexecuted instantiation: double-conversion-string-to-double.cpp:icu_70::double_conversion::uint32_to_float(unsigned int) Unexecuted instantiation: double-conversion-strtod.cpp:icu_70::double_conversion::uint32_to_float(unsigned int) Unexecuted instantiation: double-conversion-bignum-dtoa.cpp:icu_70::double_conversion::uint32_to_float(unsigned int)  | 
54  |  |  | 
55  |  | // Helper functions for doubles.  | 
56  |  | class Double { | 
57  |  |  public:  | 
58  |  |   static const uint64_t kSignMask = DOUBLE_CONVERSION_UINT64_2PART_C(0x80000000, 00000000);  | 
59  |  |   static const uint64_t kExponentMask = DOUBLE_CONVERSION_UINT64_2PART_C(0x7FF00000, 00000000);  | 
60  |  |   static const uint64_t kSignificandMask = DOUBLE_CONVERSION_UINT64_2PART_C(0x000FFFFF, FFFFFFFF);  | 
61  |  |   static const uint64_t kHiddenBit = DOUBLE_CONVERSION_UINT64_2PART_C(0x00100000, 00000000);  | 
62  |  |   static const uint64_t kQuietNanBit = DOUBLE_CONVERSION_UINT64_2PART_C(0x00080000, 00000000);  | 
63  |  |   static const int kPhysicalSignificandSize = 52;  // Excludes the hidden bit.  | 
64  |  |   static const int kSignificandSize = 53;  | 
65  |  |   static const int kExponentBias = 0x3FF + kPhysicalSignificandSize;  | 
66  |  |   static const int kMaxExponent = 0x7FF - kExponentBias;  | 
67  |  |  | 
68  | 0  |   Double() : d64_(0) {} | 
69  | 0  |   explicit Double(double d) : d64_(double_to_uint64(d)) {} | 
70  | 0  |   explicit Double(uint64_t d64) : d64_(d64) {} | 
71  |  |   explicit Double(DiyFp diy_fp)  | 
72  | 0  |     : d64_(DiyFpToUint64(diy_fp)) {} | 
73  |  |  | 
74  |  |   // The value encoded by this Double must be greater or equal to +0.0.  | 
75  |  |   // It must not be special (infinity, or NaN).  | 
76  | 0  |   DiyFp AsDiyFp() const { | 
77  | 0  |     DOUBLE_CONVERSION_ASSERT(Sign() > 0);  | 
78  | 0  |     DOUBLE_CONVERSION_ASSERT(!IsSpecial());  | 
79  | 0  |     return DiyFp(Significand(), Exponent());  | 
80  | 0  |   }  | 
81  |  |  | 
82  |  |   // The value encoded by this Double must be strictly greater than 0.  | 
83  | 0  |   DiyFp AsNormalizedDiyFp() const { | 
84  | 0  |     DOUBLE_CONVERSION_ASSERT(value() > 0.0);  | 
85  | 0  |     uint64_t f = Significand();  | 
86  | 0  |     int e = Exponent();  | 
87  |  |  | 
88  |  |     // The current double could be a denormal.  | 
89  | 0  |     while ((f & kHiddenBit) == 0) { | 
90  | 0  |       f <<= 1;  | 
91  | 0  |       e--;  | 
92  | 0  |     }  | 
93  |  |     // Do the final shifts in one go.  | 
94  | 0  |     f <<= DiyFp::kSignificandSize - kSignificandSize;  | 
95  | 0  |     e -= DiyFp::kSignificandSize - kSignificandSize;  | 
96  | 0  |     return DiyFp(f, e);  | 
97  | 0  |   }  | 
98  |  |  | 
99  |  |   // Returns the double's bit as uint64.  | 
100  | 0  |   uint64_t AsUint64() const { | 
101  | 0  |     return d64_;  | 
102  | 0  |   }  | 
103  |  |  | 
104  |  |   // Returns the next greater double. Returns +infinity on input +infinity.  | 
105  | 0  |   double NextDouble() const { | 
106  | 0  |     if (d64_ == kInfinity) return Double(kInfinity).value();  | 
107  | 0  |     if (Sign() < 0 && Significand() == 0) { | 
108  |  |       // -0.0  | 
109  | 0  |       return 0.0;  | 
110  | 0  |     }  | 
111  | 0  |     if (Sign() < 0) { | 
112  | 0  |       return Double(d64_ - 1).value();  | 
113  | 0  |     } else { | 
114  | 0  |       return Double(d64_ + 1).value();  | 
115  | 0  |     }  | 
116  | 0  |   }  | 
117  |  |  | 
118  | 0  |   double PreviousDouble() const { | 
119  | 0  |     if (d64_ == (kInfinity | kSignMask)) return -Infinity();  | 
120  | 0  |     if (Sign() < 0) { | 
121  | 0  |       return Double(d64_ + 1).value();  | 
122  | 0  |     } else { | 
123  | 0  |       if (Significand() == 0) return -0.0;  | 
124  | 0  |       return Double(d64_ - 1).value();  | 
125  | 0  |     }  | 
126  | 0  |   }  | 
127  |  |  | 
128  | 0  |   int Exponent() const { | 
129  | 0  |     if (IsDenormal()) return kDenormalExponent;  | 
130  |  |  | 
131  | 0  |     uint64_t d64 = AsUint64();  | 
132  | 0  |     int biased_e =  | 
133  | 0  |         static_cast<int>((d64 & kExponentMask) >> kPhysicalSignificandSize);  | 
134  | 0  |     return biased_e - kExponentBias;  | 
135  | 0  |   }  | 
136  |  |  | 
137  | 0  |   uint64_t Significand() const { | 
138  | 0  |     uint64_t d64 = AsUint64();  | 
139  | 0  |     uint64_t significand = d64 & kSignificandMask;  | 
140  | 0  |     if (!IsDenormal()) { | 
141  | 0  |       return significand + kHiddenBit;  | 
142  | 0  |     } else { | 
143  | 0  |       return significand;  | 
144  | 0  |     }  | 
145  | 0  |   }  | 
146  |  |  | 
147  |  |   // Returns true if the double is a denormal.  | 
148  | 0  |   bool IsDenormal() const { | 
149  | 0  |     uint64_t d64 = AsUint64();  | 
150  | 0  |     return (d64 & kExponentMask) == 0;  | 
151  | 0  |   }  | 
152  |  |  | 
153  |  |   // We consider denormals not to be special.  | 
154  |  |   // Hence only Infinity and NaN are special.  | 
155  | 0  |   bool IsSpecial() const { | 
156  | 0  |     uint64_t d64 = AsUint64();  | 
157  | 0  |     return (d64 & kExponentMask) == kExponentMask;  | 
158  | 0  |   }  | 
159  |  |  | 
160  | 0  |   bool IsNan() const { | 
161  | 0  |     uint64_t d64 = AsUint64();  | 
162  | 0  |     return ((d64 & kExponentMask) == kExponentMask) &&  | 
163  | 0  |         ((d64 & kSignificandMask) != 0);  | 
164  | 0  |   }  | 
165  |  |  | 
166  | 0  |   bool IsQuietNan() const { | 
167  | 0  |     return IsNan() && ((AsUint64() & kQuietNanBit) != 0);  | 
168  | 0  |   }  | 
169  |  |  | 
170  | 0  |   bool IsSignalingNan() const { | 
171  | 0  |     return IsNan() && ((AsUint64() & kQuietNanBit) == 0);  | 
172  | 0  |   }  | 
173  |  |  | 
174  |  |  | 
175  | 0  |   bool IsInfinite() const { | 
176  | 0  |     uint64_t d64 = AsUint64();  | 
177  | 0  |     return ((d64 & kExponentMask) == kExponentMask) &&  | 
178  | 0  |         ((d64 & kSignificandMask) == 0);  | 
179  | 0  |   }  | 
180  |  |  | 
181  | 0  |   int Sign() const { | 
182  | 0  |     uint64_t d64 = AsUint64();  | 
183  | 0  |     return (d64 & kSignMask) == 0? 1: -1;  | 
184  | 0  |   }  | 
185  |  |  | 
186  |  |   // Precondition: the value encoded by this Double must be greater or equal  | 
187  |  |   // than +0.0.  | 
188  | 0  |   DiyFp UpperBoundary() const { | 
189  | 0  |     DOUBLE_CONVERSION_ASSERT(Sign() > 0);  | 
190  | 0  |     return DiyFp(Significand() * 2 + 1, Exponent() - 1);  | 
191  | 0  |   }  | 
192  |  |  | 
193  |  |   // Computes the two boundaries of this.  | 
194  |  |   // The bigger boundary (m_plus) is normalized. The lower boundary has the same  | 
195  |  |   // exponent as m_plus.  | 
196  |  |   // Precondition: the value encoded by this Double must be greater than 0.  | 
197  | 0  |   void NormalizedBoundaries(DiyFp* out_m_minus, DiyFp* out_m_plus) const { | 
198  | 0  |     DOUBLE_CONVERSION_ASSERT(value() > 0.0);  | 
199  | 0  |     DiyFp v = this->AsDiyFp();  | 
200  | 0  |     DiyFp m_plus = DiyFp::Normalize(DiyFp((v.f() << 1) + 1, v.e() - 1));  | 
201  | 0  |     DiyFp m_minus;  | 
202  | 0  |     if (LowerBoundaryIsCloser()) { | 
203  | 0  |       m_minus = DiyFp((v.f() << 2) - 1, v.e() - 2);  | 
204  | 0  |     } else { | 
205  | 0  |       m_minus = DiyFp((v.f() << 1) - 1, v.e() - 1);  | 
206  | 0  |     }  | 
207  | 0  |     m_minus.set_f(m_minus.f() << (m_minus.e() - m_plus.e()));  | 
208  | 0  |     m_minus.set_e(m_plus.e());  | 
209  | 0  |     *out_m_plus = m_plus;  | 
210  | 0  |     *out_m_minus = m_minus;  | 
211  | 0  |   }  | 
212  |  |  | 
213  | 0  |   bool LowerBoundaryIsCloser() const { | 
214  |  |     // The boundary is closer if the significand is of the form f == 2^p-1 then  | 
215  |  |     // the lower boundary is closer.  | 
216  |  |     // Think of v = 1000e10 and v- = 9999e9.  | 
217  |  |     // Then the boundary (== (v - v-)/2) is not just at a distance of 1e9 but  | 
218  |  |     // at a distance of 1e8.  | 
219  |  |     // The only exception is for the smallest normal: the largest denormal is  | 
220  |  |     // at the same distance as its successor.  | 
221  |  |     // Note: denormals have the same exponent as the smallest normals.  | 
222  | 0  |     bool physical_significand_is_zero = ((AsUint64() & kSignificandMask) == 0);  | 
223  | 0  |     return physical_significand_is_zero && (Exponent() != kDenormalExponent);  | 
224  | 0  |   }  | 
225  |  |  | 
226  | 0  |   double value() const { return uint64_to_double(d64_); } | 
227  |  |  | 
228  |  |   // Returns the significand size for a given order of magnitude.  | 
229  |  |   // If v = f*2^e with 2^p-1 <= f <= 2^p then p+e is v's order of magnitude.  | 
230  |  |   // This function returns the number of significant binary digits v will have  | 
231  |  |   // once it's encoded into a double. In almost all cases this is equal to  | 
232  |  |   // kSignificandSize. The only exceptions are denormals. They start with  | 
233  |  |   // leading zeroes and their effective significand-size is hence smaller.  | 
234  | 0  |   static int SignificandSizeForOrderOfMagnitude(int order) { | 
235  | 0  |     if (order >= (kDenormalExponent + kSignificandSize)) { | 
236  | 0  |       return kSignificandSize;  | 
237  | 0  |     }  | 
238  | 0  |     if (order <= kDenormalExponent) return 0;  | 
239  | 0  |     return order - kDenormalExponent;  | 
240  | 0  |   }  | 
241  |  |  | 
242  | 0  |   static double Infinity() { | 
243  | 0  |     return Double(kInfinity).value();  | 
244  | 0  |   }  | 
245  |  |  | 
246  | 0  |   static double NaN() { | 
247  | 0  |     return Double(kNaN).value();  | 
248  | 0  |   }  | 
249  |  |  | 
250  |  |  private:  | 
251  |  |   static const int kDenormalExponent = -kExponentBias + 1;  | 
252  |  |   static const uint64_t kInfinity = DOUBLE_CONVERSION_UINT64_2PART_C(0x7FF00000, 00000000);  | 
253  |  |   static const uint64_t kNaN = DOUBLE_CONVERSION_UINT64_2PART_C(0x7FF80000, 00000000);  | 
254  |  |  | 
255  |  |   const uint64_t d64_;  | 
256  |  |  | 
257  | 0  |   static uint64_t DiyFpToUint64(DiyFp diy_fp) { | 
258  | 0  |     uint64_t significand = diy_fp.f();  | 
259  | 0  |     int exponent = diy_fp.e();  | 
260  | 0  |     while (significand > kHiddenBit + kSignificandMask) { | 
261  | 0  |       significand >>= 1;  | 
262  | 0  |       exponent++;  | 
263  | 0  |     }  | 
264  | 0  |     if (exponent >= kMaxExponent) { | 
265  | 0  |       return kInfinity;  | 
266  | 0  |     }  | 
267  | 0  |     if (exponent < kDenormalExponent) { | 
268  | 0  |       return 0;  | 
269  | 0  |     }  | 
270  | 0  |     while (exponent > kDenormalExponent && (significand & kHiddenBit) == 0) { | 
271  | 0  |       significand <<= 1;  | 
272  | 0  |       exponent--;  | 
273  | 0  |     }  | 
274  | 0  |     uint64_t biased_exponent;  | 
275  | 0  |     if (exponent == kDenormalExponent && (significand & kHiddenBit) == 0) { | 
276  | 0  |       biased_exponent = 0;  | 
277  | 0  |     } else { | 
278  | 0  |       biased_exponent = static_cast<uint64_t>(exponent + kExponentBias);  | 
279  | 0  |     }  | 
280  | 0  |     return (significand & kSignificandMask) |  | 
281  | 0  |         (biased_exponent << kPhysicalSignificandSize);  | 
282  | 0  |   }  | 
283  |  |  | 
284  |  |   DOUBLE_CONVERSION_DISALLOW_COPY_AND_ASSIGN(Double);  | 
285  |  | };  | 
286  |  |  | 
287  |  | class Single { | 
288  |  |  public:  | 
289  |  |   static const uint32_t kSignMask = 0x80000000;  | 
290  |  |   static const uint32_t kExponentMask = 0x7F800000;  | 
291  |  |   static const uint32_t kSignificandMask = 0x007FFFFF;  | 
292  |  |   static const uint32_t kHiddenBit = 0x00800000;  | 
293  |  |   static const uint32_t kQuietNanBit = 0x00400000;  | 
294  |  |   static const int kPhysicalSignificandSize = 23;  // Excludes the hidden bit.  | 
295  |  |   static const int kSignificandSize = 24;  | 
296  |  |  | 
297  | 0  |   Single() : d32_(0) {} | 
298  | 0  |   explicit Single(float f) : d32_(float_to_uint32(f)) {} | 
299  | 0  |   explicit Single(uint32_t d32) : d32_(d32) {} | 
300  |  |  | 
301  |  |   // The value encoded by this Single must be greater or equal to +0.0.  | 
302  |  |   // It must not be special (infinity, or NaN).  | 
303  | 0  |   DiyFp AsDiyFp() const { | 
304  | 0  |     DOUBLE_CONVERSION_ASSERT(Sign() > 0);  | 
305  | 0  |     DOUBLE_CONVERSION_ASSERT(!IsSpecial());  | 
306  | 0  |     return DiyFp(Significand(), Exponent());  | 
307  | 0  |   }  | 
308  |  |  | 
309  |  |   // Returns the single's bit as uint64.  | 
310  | 0  |   uint32_t AsUint32() const { | 
311  | 0  |     return d32_;  | 
312  | 0  |   }  | 
313  |  |  | 
314  | 0  |   int Exponent() const { | 
315  | 0  |     if (IsDenormal()) return kDenormalExponent;  | 
316  |  |  | 
317  | 0  |     uint32_t d32 = AsUint32();  | 
318  | 0  |     int biased_e =  | 
319  | 0  |         static_cast<int>((d32 & kExponentMask) >> kPhysicalSignificandSize);  | 
320  | 0  |     return biased_e - kExponentBias;  | 
321  | 0  |   }  | 
322  |  |  | 
323  | 0  |   uint32_t Significand() const { | 
324  | 0  |     uint32_t d32 = AsUint32();  | 
325  | 0  |     uint32_t significand = d32 & kSignificandMask;  | 
326  | 0  |     if (!IsDenormal()) { | 
327  | 0  |       return significand + kHiddenBit;  | 
328  | 0  |     } else { | 
329  | 0  |       return significand;  | 
330  | 0  |     }  | 
331  | 0  |   }  | 
332  |  |  | 
333  |  |   // Returns true if the single is a denormal.  | 
334  | 0  |   bool IsDenormal() const { | 
335  | 0  |     uint32_t d32 = AsUint32();  | 
336  | 0  |     return (d32 & kExponentMask) == 0;  | 
337  | 0  |   }  | 
338  |  |  | 
339  |  |   // We consider denormals not to be special.  | 
340  |  |   // Hence only Infinity and NaN are special.  | 
341  | 0  |   bool IsSpecial() const { | 
342  | 0  |     uint32_t d32 = AsUint32();  | 
343  | 0  |     return (d32 & kExponentMask) == kExponentMask;  | 
344  | 0  |   }  | 
345  |  |  | 
346  | 0  |   bool IsNan() const { | 
347  | 0  |     uint32_t d32 = AsUint32();  | 
348  | 0  |     return ((d32 & kExponentMask) == kExponentMask) &&  | 
349  | 0  |         ((d32 & kSignificandMask) != 0);  | 
350  | 0  |   }  | 
351  |  |  | 
352  | 0  |   bool IsQuietNan() const { | 
353  | 0  |     return IsNan() && ((AsUint32() & kQuietNanBit) != 0);  | 
354  | 0  |   }  | 
355  |  |  | 
356  | 0  |   bool IsSignalingNan() const { | 
357  | 0  |     return IsNan() && ((AsUint32() & kQuietNanBit) == 0);  | 
358  | 0  |   }  | 
359  |  |  | 
360  |  |  | 
361  | 0  |   bool IsInfinite() const { | 
362  | 0  |     uint32_t d32 = AsUint32();  | 
363  | 0  |     return ((d32 & kExponentMask) == kExponentMask) &&  | 
364  | 0  |         ((d32 & kSignificandMask) == 0);  | 
365  | 0  |   }  | 
366  |  |  | 
367  | 0  |   int Sign() const { | 
368  | 0  |     uint32_t d32 = AsUint32();  | 
369  | 0  |     return (d32 & kSignMask) == 0? 1: -1;  | 
370  | 0  |   }  | 
371  |  |  | 
372  |  |   // Computes the two boundaries of this.  | 
373  |  |   // The bigger boundary (m_plus) is normalized. The lower boundary has the same  | 
374  |  |   // exponent as m_plus.  | 
375  |  |   // Precondition: the value encoded by this Single must be greater than 0.  | 
376  | 0  |   void NormalizedBoundaries(DiyFp* out_m_minus, DiyFp* out_m_plus) const { | 
377  | 0  |     DOUBLE_CONVERSION_ASSERT(value() > 0.0);  | 
378  | 0  |     DiyFp v = this->AsDiyFp();  | 
379  | 0  |     DiyFp m_plus = DiyFp::Normalize(DiyFp((v.f() << 1) + 1, v.e() - 1));  | 
380  | 0  |     DiyFp m_minus;  | 
381  | 0  |     if (LowerBoundaryIsCloser()) { | 
382  | 0  |       m_minus = DiyFp((v.f() << 2) - 1, v.e() - 2);  | 
383  | 0  |     } else { | 
384  | 0  |       m_minus = DiyFp((v.f() << 1) - 1, v.e() - 1);  | 
385  | 0  |     }  | 
386  | 0  |     m_minus.set_f(m_minus.f() << (m_minus.e() - m_plus.e()));  | 
387  | 0  |     m_minus.set_e(m_plus.e());  | 
388  | 0  |     *out_m_plus = m_plus;  | 
389  | 0  |     *out_m_minus = m_minus;  | 
390  | 0  |   }  | 
391  |  |  | 
392  |  |   // Precondition: the value encoded by this Single must be greater or equal  | 
393  |  |   // than +0.0.  | 
394  | 0  |   DiyFp UpperBoundary() const { | 
395  | 0  |     DOUBLE_CONVERSION_ASSERT(Sign() > 0);  | 
396  | 0  |     return DiyFp(Significand() * 2 + 1, Exponent() - 1);  | 
397  | 0  |   }  | 
398  |  |  | 
399  | 0  |   bool LowerBoundaryIsCloser() const { | 
400  |  |     // The boundary is closer if the significand is of the form f == 2^p-1 then  | 
401  |  |     // the lower boundary is closer.  | 
402  |  |     // Think of v = 1000e10 and v- = 9999e9.  | 
403  |  |     // Then the boundary (== (v - v-)/2) is not just at a distance of 1e9 but  | 
404  |  |     // at a distance of 1e8.  | 
405  |  |     // The only exception is for the smallest normal: the largest denormal is  | 
406  |  |     // at the same distance as its successor.  | 
407  |  |     // Note: denormals have the same exponent as the smallest normals.  | 
408  | 0  |     bool physical_significand_is_zero = ((AsUint32() & kSignificandMask) == 0);  | 
409  | 0  |     return physical_significand_is_zero && (Exponent() != kDenormalExponent);  | 
410  | 0  |   }  | 
411  |  |  | 
412  | 0  |   float value() const { return uint32_to_float(d32_); } | 
413  |  |  | 
414  | 0  |   static float Infinity() { | 
415  | 0  |     return Single(kInfinity).value();  | 
416  | 0  |   }  | 
417  |  |  | 
418  | 0  |   static float NaN() { | 
419  | 0  |     return Single(kNaN).value();  | 
420  | 0  |   }  | 
421  |  |  | 
422  |  |  private:  | 
423  |  |   static const int kExponentBias = 0x7F + kPhysicalSignificandSize;  | 
424  |  |   static const int kDenormalExponent = -kExponentBias + 1;  | 
425  |  |   static const int kMaxExponent = 0xFF - kExponentBias;  | 
426  |  |   static const uint32_t kInfinity = 0x7F800000;  | 
427  |  |   static const uint32_t kNaN = 0x7FC00000;  | 
428  |  |  | 
429  |  |   const uint32_t d32_;  | 
430  |  |  | 
431  |  |   DOUBLE_CONVERSION_DISALLOW_COPY_AND_ASSIGN(Single);  | 
432  |  | };  | 
433  |  |  | 
434  |  | }  // namespace double_conversion  | 
435  |  |  | 
436  |  | // ICU PATCH: Close ICU namespace  | 
437  |  | U_NAMESPACE_END  | 
438  |  |  | 
439  |  | #endif  // DOUBLE_CONVERSION_DOUBLE_H_  | 
440  |  | #endif // ICU PATCH: close #if !UCONFIG_NO_FORMATTING  |