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#include <climits>

#include <cmath>

#include <cstdarg>

#include <double-conversion/utils.h>

#include <double-conversion/cached-powers.h>

namespace double_conversion {

struct CachedPower {

  uint64_t significand;

  int16_t binary_exponent;

  int16_t decimal_exponent;

};

static const CachedPower kCachedPowers[] = {

  {UINT64_2PART_C(0xfa8fd5a0, 081c0288), -1220, -348},

  {UINT64_2PART_C(0xbaaee17f, a23ebf76), -1193, -340},

  {UINT64_2PART_C(0x8b16fb20, 3055ac76), -1166, -332},

  {UINT64_2PART_C(0xcf42894a, 5dce35ea), -1140, -324},

  {UINT64_2PART_C(0x9a6bb0aa, 55653b2d), -1113, -316},

  {UINT64_2PART_C(0xe61acf03, 3d1a45df), -1087, -308},

  {UINT64_2PART_C(0xab70fe17, c79ac6ca), -1060, -300},

  {UINT64_2PART_C(0xff77b1fc, bebcdc4f), -1034, -292},

  {UINT64_2PART_C(0xbe5691ef, 416bd60c), -1007, -284},

  {UINT64_2PART_C(0x8dd01fad, 907ffc3c), -980, -276},

  {UINT64_2PART_C(0xd3515c28, 31559a83), -954, -268},

  {UINT64_2PART_C(0x9d71ac8f, ada6c9b5), -927, -260},

  {UINT64_2PART_C(0xea9c2277, 23ee8bcb), -901, -252},

  {UINT64_2PART_C(0xaecc4991, 4078536d), -874, -244},

  {UINT64_2PART_C(0x823c1279, 5db6ce57), -847, -236},

  {UINT64_2PART_C(0xc2109436, 4dfb5637), -821, -228},

  {UINT64_2PART_C(0x9096ea6f, 3848984f), -794, -220},

  {UINT64_2PART_C(0xd77485cb, 25823ac7), -768, -212},

  {UINT64_2PART_C(0xa086cfcd, 97bf97f4), -741, -204},

  {UINT64_2PART_C(0xef340a98, 172aace5), -715, -196},

  {UINT64_2PART_C(0xb23867fb, 2a35b28e), -688, -188},

  {UINT64_2PART_C(0x84c8d4df, d2c63f3b), -661, -180},

  {UINT64_2PART_C(0xc5dd4427, 1ad3cdba), -635, -172},

  {UINT64_2PART_C(0x936b9fce, bb25c996), -608, -164},

  {UINT64_2PART_C(0xdbac6c24, 7d62a584), -582, -156},

  {UINT64_2PART_C(0xa3ab6658, 0d5fdaf6), -555, -148},

  {UINT64_2PART_C(0xf3e2f893, dec3f126), -529, -140},

  {UINT64_2PART_C(0xb5b5ada8, aaff80b8), -502, -132},

  {UINT64_2PART_C(0x87625f05, 6c7c4a8b), -475, -124},

  {UINT64_2PART_C(0xc9bcff60, 34c13053), -449, -116},

  {UINT64_2PART_C(0x964e858c, 91ba2655), -422, -108},

  {UINT64_2PART_C(0xdff97724, 70297ebd), -396, -100},

  {UINT64_2PART_C(0xa6dfbd9f, b8e5b88f), -369, -92},

  {UINT64_2PART_C(0xf8a95fcf, 88747d94), -343, -84},

  {UINT64_2PART_C(0xb9447093, 8fa89bcf), -316, -76},

  {UINT64_2PART_C(0x8a08f0f8, bf0f156b), -289, -68},

  {UINT64_2PART_C(0xcdb02555, 653131b6), -263, -60},

  {UINT64_2PART_C(0x993fe2c6, d07b7fac), -236, -52},

  {UINT64_2PART_C(0xe45c10c4, 2a2b3b06), -210, -44},

  {UINT64_2PART_C(0xaa242499, 697392d3), -183, -36},

  {UINT64_2PART_C(0xfd87b5f2, 8300ca0e), -157, -28},

  {UINT64_2PART_C(0xbce50864, 92111aeb), -130, -20},

  {UINT64_2PART_C(0x8cbccc09, 6f5088cc), -103, -12},

  {UINT64_2PART_C(0xd1b71758, e219652c), -77, -4},

  {UINT64_2PART_C(0x9c400000, 00000000), -50, 4},

  {UINT64_2PART_C(0xe8d4a510, 00000000), -24, 12},

  {UINT64_2PART_C(0xad78ebc5, ac620000), 3, 20},

  {UINT64_2PART_C(0x813f3978, f8940984), 30, 28},

  {UINT64_2PART_C(0xc097ce7b, c90715b3), 56, 36},

  {UINT64_2PART_C(0x8f7e32ce, 7bea5c70), 83, 44},

  {UINT64_2PART_C(0xd5d238a4, abe98068), 109, 52},

  {UINT64_2PART_C(0x9f4f2726, 179a2245), 136, 60},

  {UINT64_2PART_C(0xed63a231, d4c4fb27), 162, 68},

  {UINT64_2PART_C(0xb0de6538, 8cc8ada8), 189, 76},

  {UINT64_2PART_C(0x83c7088e, 1aab65db), 216, 84},

  {UINT64_2PART_C(0xc45d1df9, 42711d9a), 242, 92},

  {UINT64_2PART_C(0x924d692c, a61be758), 269, 100},

  {UINT64_2PART_C(0xda01ee64, 1a708dea), 295, 108},

  {UINT64_2PART_C(0xa26da399, 9aef774a), 322, 116},

  {UINT64_2PART_C(0xf209787b, b47d6b85), 348, 124},

  {UINT64_2PART_C(0xb454e4a1, 79dd1877), 375, 132},

  {UINT64_2PART_C(0x865b8692, 5b9bc5c2), 402, 140},

  {UINT64_2PART_C(0xc83553c5, c8965d3d), 428, 148},

  {UINT64_2PART_C(0x952ab45c, fa97a0b3), 455, 156},

  {UINT64_2PART_C(0xde469fbd, 99a05fe3), 481, 164},

  {UINT64_2PART_C(0xa59bc234, db398c25), 508, 172},

  {UINT64_2PART_C(0xf6c69a72, a3989f5c), 534, 180},

  {UINT64_2PART_C(0xb7dcbf53, 54e9bece), 561, 188},

  {UINT64_2PART_C(0x88fcf317, f22241e2), 588, 196},

  {UINT64_2PART_C(0xcc20ce9b, d35c78a5), 614, 204},

  {UINT64_2PART_C(0x98165af3, 7b2153df), 641, 212},

  {UINT64_2PART_C(0xe2a0b5dc, 971f303a), 667, 220},

  {UINT64_2PART_C(0xa8d9d153, 5ce3b396), 694, 228},

  {UINT64_2PART_C(0xfb9b7cd9, a4a7443c), 720, 236},

  {UINT64_2PART_C(0xbb764c4c, a7a44410), 747, 244},

  {UINT64_2PART_C(0x8bab8eef, b6409c1a), 774, 252},

  {UINT64_2PART_C(0xd01fef10, a657842c), 800, 260},

  {UINT64_2PART_C(0x9b10a4e5, e9913129), 827, 268},

  {UINT64_2PART_C(0xe7109bfb, a19c0c9d), 853, 276},

  {UINT64_2PART_C(0xac2820d9, 623bf429), 880, 284},

  {UINT64_2PART_C(0x80444b5e, 7aa7cf85), 907, 292},

  {UINT64_2PART_C(0xbf21e440, 03acdd2d), 933, 300},

  {UINT64_2PART_C(0x8e679c2f, 5e44ff8f), 960, 308},

  {UINT64_2PART_C(0xd433179d, 9c8cb841), 986, 316},

  {UINT64_2PART_C(0x9e19db92, b4e31ba9), 1013, 324},

  {UINT64_2PART_C(0xeb96bf6e, badf77d9), 1039, 332},

  {UINT64_2PART_C(0xaf87023b, 9bf0ee6b), 1066, 340},

};

static const int kCachedPowersOffset = 348;  // -1 * the first decimal_exponent.

static const double kD_1_LOG2_10 = 0.30102999566398114;  //  1 / lg(10)

// Difference between the decimal exponents in the table above.

const int PowersOfTenCache::kDecimalExponentDistance = 8;

const int PowersOfTenCache::kMinDecimalExponent = -348;

const int PowersOfTenCache::kMaxDecimalExponent = 340;

void PowersOfTenCache::GetCachedPowerForBinaryExponentRange(

    int min_exponent,

    int max_exponent,

    DiyFp* power,

    int* decimal_exponent) {

  int kQ = DiyFp::kSignificandSize;

  double k = ceil((min_exponent + kQ - 1) * kD_1_LOG2_10);

  int foo = kCachedPowersOffset;

  int index =

      (foo + static_cast<int>(k) - 1) / kDecimalExponentDistance + 1;

  ASSERT(0 <= index && index < static_cast<int>(ARRAY_SIZE(kCachedPowers)));

  CachedPower cached_power = kCachedPowers[index];

  ASSERT(min_exponent <= cached_power.binary_exponent);

  (void) max_exponent;  // Mark variable as used.

  ASSERT(cached_power.binary_exponent <= max_exponent);

  *decimal_exponent = cached_power.decimal_exponent;

  *power = DiyFp(cached_power.significand, cached_power.binary_exponent);

}

void PowersOfTenCache::GetCachedPowerForDecimalExponent(int requested_exponent,

                                                        DiyFp* power,

                                                        int* found_exponent) {

  ASSERT(kMinDecimalExponent <= requested_exponent);

  ASSERT(requested_exponent < kMaxDecimalExponent + kDecimalExponentDistance);

  int index =

      (requested_exponent + kCachedPowersOffset) / kDecimalExponentDistance;

  CachedPower cached_power = kCachedPowers[index];

  *power = DiyFp(cached_power.significand, cached_power.binary_exponent);

  *found_exponent = cached_power.decimal_exponent;

  ASSERT(*found_exponent <= requested_exponent);

  ASSERT(requested_exponent < *found_exponent + kDecimalExponentDistance);

}

}  // namespace double_conversion