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27
28#ifndef DOUBLE_CONVERSION_CACHED_POWERS_H_
29#define DOUBLE_CONVERSION_CACHED_POWERS_H_
30
31#include "diy-fp.h"
32
33namespace WTF {
34
35namespace double_conversion {
36
37    class PowersOfTenCache {
38    public:
39
40        // Not all powers of ten are cached. The decimal exponent of two neighboring
41        // cached numbers will differ by kDecimalExponentDistance.
42        static const int kDecimalExponentDistance;
43
44        static const int kMinDecimalExponent;
45        static const int kMaxDecimalExponent;
46
47        // Returns a cached power-of-ten with a binary exponent in the range
48        // [min_exponent; max_exponent] (boundaries included).
49        static void GetCachedPowerForBinaryExponentRange(int min_exponent,
50                                                         int max_exponent,
51                                                         DiyFp* power,
52                                                         int* decimal_exponent);
53
54        // Returns a cached power of ten x ~= 10^k such that
55        //   k <= decimal_exponent < k + kCachedPowersDecimalDistance.
56        // The given decimal_exponent must satisfy
57        //   kMinDecimalExponent <= requested_exponent, and
58        //   requested_exponent < kMaxDecimalExponent + kDecimalExponentDistance.
59        static void GetCachedPowerForDecimalExponent(int requested_exponent,
60                                                     DiyFp* power,
61                                                     int* found_exponent);
62    };
63}  // namespace double_conversion
64
65} // namespace WTF
66
67#endif  // DOUBLE_CONVERSION_CACHED_POWERS_H_
68