v8  3.14.5(node0.10.28)
V8 is Google's open source JavaScript engine
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Friends Macros Pages
cached-powers.h
Go to the documentation of this file.
1 // Copyright 2010 the V8 project authors. All rights reserved.
2 // Redistribution and use in source and binary forms, with or without
3 // modification, are permitted provided that the following conditions are
4 // met:
5 //
6 // * Redistributions of source code must retain the above copyright
7 // notice, this list of conditions and the following disclaimer.
8 // * Redistributions in binary form must reproduce the above
9 // copyright notice, this list of conditions and the following
10 // disclaimer in the documentation and/or other materials provided
11 // with the distribution.
12 // * Neither the name of Google Inc. nor the names of its
13 // contributors may be used to endorse or promote products derived
14 // from this software without specific prior written permission.
15 //
16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 
28 #ifndef V8_CACHED_POWERS_H_
29 #define V8_CACHED_POWERS_H_
30 
31 #include "diy-fp.h"
32 
33 namespace v8 {
34 namespace internal {
35 
37  public:
38  // Not all powers of ten are cached. The decimal exponent of two neighboring
39  // cached numbers will differ by kDecimalExponentDistance.
40  static const int kDecimalExponentDistance;
41 
42  static const int kMinDecimalExponent;
43  static const int kMaxDecimalExponent;
44 
45  // Returns a cached power-of-ten with a binary exponent in the range
46  // [min_exponent; max_exponent] (boundaries included).
47  static void GetCachedPowerForBinaryExponentRange(int min_exponent,
48  int max_exponent,
49  DiyFp* power,
50  int* decimal_exponent);
51 
52  // Returns a cached power of ten x ~= 10^k such that
53  // k <= decimal_exponent < k + kCachedPowersDecimalDistance.
54  // The given decimal_exponent must satisfy
55  // kMinDecimalExponent <= requested_exponent, and
56  // requested_exponent < kMaxDecimalExponent + kDecimalExponentDistance.
57  static void GetCachedPowerForDecimalExponent(int requested_exponent,
58  DiyFp* power,
59  int* found_exponent);
60 };
61 
62 } } // namespace v8::internal
63 
64 #endif // V8_CACHED_POWERS_H_
static const int kMaxDecimalExponent
Definition: cached-powers.h:43
static const int kMinDecimalExponent
Definition: cached-powers.h:42
static const int kDecimalExponentDistance
Definition: cached-powers.h:40
static void GetCachedPowerForBinaryExponentRange(int min_exponent, int max_exponent, DiyFp *power, int *decimal_exponent)
static void GetCachedPowerForDecimalExponent(int requested_exponent, DiyFp *power, int *found_exponent)