// Copyright 2010 the V8 project authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #ifndef V8_CACHED_POWERS_H_ #define V8_CACHED_POWERS_H_ #include "src/base/logging.h" #include "src/diy-fp.h" namespace v8 { namespace internal { class PowersOfTenCache { public: // Not all powers of ten are cached. The decimal exponent of two neighboring // cached numbers will differ by kDecimalExponentDistance. static const int kDecimalExponentDistance; static const int kMinDecimalExponent; static const int kMaxDecimalExponent; // Returns a cached power-of-ten with a binary exponent in the range // [min_exponent; max_exponent] (boundaries included). static void GetCachedPowerForBinaryExponentRange(int min_exponent, int max_exponent, DiyFp* power, int* decimal_exponent); // Returns a cached power of ten x ~= 10^k such that // k <= decimal_exponent < k + kCachedPowersDecimalDistance. // The given decimal_exponent must satisfy // kMinDecimalExponent <= requested_exponent, and // requested_exponent < kMaxDecimalExponent + kDecimalExponentDistance. static void GetCachedPowerForDecimalExponent(int requested_exponent, DiyFp* power, int* found_exponent); }; } // namespace internal } // namespace v8 #endif // V8_CACHED_POWERS_H_