include/double-conversion/cached-powers.h

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0027
0028 #ifndef DOUBLE_CONVERSION_CACHED_POWERS_H_
0029 #define DOUBLE_CONVERSION_CACHED_POWERS_H_
0030
0031 #include "diy-fp.h"
0032
0033 namespace double_conversion {
0034
0035 namespace PowersOfTenCache {
0036
0037   // Not all powers of ten are cached. The decimal exponent of two neighboring
0038   // cached numbers will differ by kDecimalExponentDistance.
0039   static const int kDecimalExponentDistance = 8;
0040
0041   static const int kMinDecimalExponent = -348;
0042   static const int kMaxDecimalExponent = 340;
0043
0044   // Returns a cached power-of-ten with a binary exponent in the range
0045   // [min_exponent; max_exponent] (boundaries included).
0046   void GetCachedPowerForBinaryExponentRange(int min_exponent,
0047                                             int max_exponent,
0048                                             DiyFp* power,
0049                                             int* decimal_exponent);
0050
0051   // Returns a cached power of ten x ~= 10^k such that
0052   //   k <= decimal_exponent < k + kCachedPowersDecimalDistance.
0053   // The given decimal_exponent must satisfy
0054   //   kMinDecimalExponent <= requested_exponent, and
0055   //   requested_exponent < kMaxDecimalExponent + kDecimalExponentDistance.
0056   void GetCachedPowerForDecimalExponent(int requested_exponent,
0057                                         DiyFp* power,
0058                                         int* found_exponent);
0059
0060 }  // namespace PowersOfTenCache
0061
0062 }  // namespace double_conversion
0063
0064 #endif  // DOUBLE_CONVERSION_CACHED_POWERS_H_