michael@0: // Copyright 2010 the V8 project authors. All rights reserved.
michael@0: // Redistribution and use in source and binary forms, with or without
michael@0: // modification, are permitted provided that the following conditions are
michael@0: // met:
michael@0: //
michael@0: //     * Redistributions of source code must retain the above copyright
michael@0: //       notice, this list of conditions and the following disclaimer.
michael@0: //     * Redistributions in binary form must reproduce the above
michael@0: //       copyright notice, this list of conditions and the following
michael@0: //       disclaimer in the documentation and/or other materials provided
michael@0: //       with the distribution.
michael@0: //     * Neither the name of Google Inc. nor the names of its
michael@0: //       contributors may be used to endorse or promote products derived
michael@0: //       from this software without specific prior written permission.
michael@0: //
michael@0: // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
michael@0: // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
michael@0: // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
michael@0: // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
michael@0: // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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michael@0: // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
michael@0: // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
michael@0: // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
michael@0: // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
michael@0: // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
michael@0: 
michael@0: #ifndef DOUBLE_CONVERSION_CACHED_POWERS_H_
michael@0: #define DOUBLE_CONVERSION_CACHED_POWERS_H_
michael@0: 
michael@0: #include "diy-fp.h"
michael@0: 
michael@0: namespace double_conversion {
michael@0: 
michael@0: class PowersOfTenCache {
michael@0:  public:
michael@0: 
michael@0:   // Not all powers of ten are cached. The decimal exponent of two neighboring
michael@0:   // cached numbers will differ by kDecimalExponentDistance.
michael@0:   static const int kDecimalExponentDistance;
michael@0: 
michael@0:   static const int kMinDecimalExponent;
michael@0:   static const int kMaxDecimalExponent;
michael@0: 
michael@0:   // Returns a cached power-of-ten with a binary exponent in the range
michael@0:   // [min_exponent; max_exponent] (boundaries included).
michael@0:   static void GetCachedPowerForBinaryExponentRange(int min_exponent,
michael@0:                                                    int max_exponent,
michael@0:                                                    DiyFp* power,
michael@0:                                                    int* decimal_exponent);
michael@0: 
michael@0:   // Returns a cached power of ten x ~= 10^k such that
michael@0:   //   k <= decimal_exponent < k + kCachedPowersDecimalDistance.
michael@0:   // The given decimal_exponent must satisfy
michael@0:   //   kMinDecimalExponent <= requested_exponent, and
michael@0:   //   requested_exponent < kMaxDecimalExponent + kDecimalExponentDistance.
michael@0:   static void GetCachedPowerForDecimalExponent(int requested_exponent,
michael@0:                                                DiyFp* power,
michael@0:                                                int* found_exponent);
michael@0: };
michael@0: 
michael@0: }  // namespace double_conversion
michael@0: 
michael@0: #endif  // DOUBLE_CONVERSION_CACHED_POWERS_H_