third_party/WebKit/Source/wtf/dtoa/cached-powers.h

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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
  33 namespace WTF {
  34
  35 namespace 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_