vendored/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 arrow_vendored {
0034 namespace double_conversion {
0035
0036 namespace PowersOfTenCache {
0037
0038   // Not all powers of ten are cached. The decimal exponent of two neighboring
0039   // cached numbers will differ by kDecimalExponentDistance.
0040   static const int kDecimalExponentDistance = 8;
0041
0042   static const int kMinDecimalExponent = -348;
0043   static const int kMaxDecimalExponent = 340;
0044
0045   // Returns a cached power-of-ten with a binary exponent in the range
0046   // [min_exponent; max_exponent] (boundaries included).
0047   void GetCachedPowerForBinaryExponentRange(int min_exponent,
0048                                             int max_exponent,
0049                                             DiyFp* power,
0050                                             int* decimal_exponent);
0051
0052   // Returns a cached power of ten x ~= 10^k such that
0053   //   k <= decimal_exponent < k + kCachedPowersDecimalDistance.
0054   // The given decimal_exponent must satisfy
0055   //   kMinDecimalExponent <= requested_exponent, and
0056   //   requested_exponent < kMaxDecimalExponent + kDecimalExponentDistance.
0057   void GetCachedPowerForDecimalExponent(int requested_exponent,
0058                                         DiyFp* power,
0059                                         int* found_exponent);
0060
0061 }  // namespace PowersOfTenCache
0062
0063 }  // namespace double_conversion
0064 }  // namespace arrow_vendored
0065
0066 #endif  // DOUBLE_CONVERSION_CACHED_POWERS_H_