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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 #include "pxr/pxr.h"
34 
35 PXR_NAMESPACE_OPEN_SCOPE
36 
37 namespace pxr_double_conversion {
38 
39 class PowersOfTenCache {
40  public:
41 
42  // Not all powers of ten are cached. The decimal exponent of two neighboring
43  // cached numbers will differ by kDecimalExponentDistance.
44  static const int kDecimalExponentDistance;
45 
46  static const int kMinDecimalExponent;
47  static const int kMaxDecimalExponent;
48 
49  // Returns a cached power-of-ten with a binary exponent in the range
50  // [min_exponent; max_exponent] (boundaries included).
51  static void GetCachedPowerForBinaryExponentRange(int min_exponent,
52  int max_exponent,
53  DiyFp* power,
54  int* decimal_exponent);
55 
56  // Returns a cached power of ten x ~= 10^k such that
57  // k <= decimal_exponent < k + kCachedPowersDecimalDistance.
58  // The given decimal_exponent must satisfy
59  // kMinDecimalExponent <= requested_exponent, and
60  // requested_exponent < kMaxDecimalExponent + kDecimalExponentDistance.
61  static void GetCachedPowerForDecimalExponent(int requested_exponent,
62  DiyFp* power,
63  int* found_exponent);
64 };
65 
66 } // namespace pxr_double_conversion
67 
68 PXR_NAMESPACE_CLOSE_SCOPE
69 
70 #endif // DOUBLE_CONVERSION_CACHED_POWERS_H_