83 lines
3.2 KiB
Go
83 lines
3.2 KiB
Go
package fpconv
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var (
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npowers int64 = 87
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steppowers int64 = 8
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firstpower int64 = -348 /* 10 ^ -348 */
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expmax = -32
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expmin = -60
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powers_ten = []Fp{
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{18054884314459144840, -1220}, {13451937075301367670, -1193},
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{10022474136428063862, -1166}, {14934650266808366570, -1140},
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{11127181549972568877, -1113}, {16580792590934885855, -1087},
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{12353653155963782858, -1060}, {18408377700990114895, -1034},
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{13715310171984221708, -1007}, {10218702384817765436, -980},
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{15227053142812498563, -954}, {11345038669416679861, -927},
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{16905424996341287883, -901}, {12595523146049147757, -874},
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{9384396036005875287, -847}, {13983839803942852151, -821},
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{10418772551374772303, -794}, {15525180923007089351, -768},
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{11567161174868858868, -741}, {17236413322193710309, -715},
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{12842128665889583758, -688}, {9568131466127621947, -661},
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{14257626930069360058, -635}, {10622759856335341974, -608},
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{15829145694278690180, -582}, {11793632577567316726, -555},
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{17573882009934360870, -529}, {13093562431584567480, -502},
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{9755464219737475723, -475}, {14536774485912137811, -449},
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{10830740992659433045, -422}, {16139061738043178685, -396},
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{12024538023802026127, -369}, {17917957937422433684, -343},
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{13349918974505688015, -316}, {9946464728195732843, -289},
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{14821387422376473014, -263}, {11042794154864902060, -236},
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{16455045573212060422, -210}, {12259964326927110867, -183},
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{18268770466636286478, -157}, {13611294676837538539, -130},
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{10141204801825835212, -103}, {15111572745182864684, -77},
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{11258999068426240000, -50}, {16777216000000000000, -24},
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{12500000000000000000, 3}, {9313225746154785156, 30},
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{13877787807814456755, 56}, {10339757656912845936, 83},
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{15407439555097886824, 109}, {11479437019748901445, 136},
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{17105694144590052135, 162}, {12744735289059618216, 189},
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{9495567745759798747, 216}, {14149498560666738074, 242},
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{10542197943230523224, 269}, {15709099088952724970, 295},
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{11704190886730495818, 322}, {17440603504673385349, 348},
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{12994262207056124023, 375}, {9681479787123295682, 402},
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{14426529090290212157, 428}, {10748601772107342003, 455},
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{16016664761464807395, 481}, {11933345169920330789, 508},
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{17782069995880619868, 534}, {13248674568444952270, 561},
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{9871031767461413346, 588}, {14708983551653345445, 614},
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{10959046745042015199, 641}, {16330252207878254650, 667},
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{12166986024289022870, 694}, {18130221999122236476, 720},
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{13508068024458167312, 747}, {10064294952495520794, 774},
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{14996968138956309548, 800}, {11173611982879273257, 827},
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{16649979327439178909, 853}, {12405201291620119593, 880},
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{9242595204427927429, 907}, {13772540099066387757, 933},
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{10261342003245940623, 960}, {15290591125556738113, 986},
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{11392378155556871081, 1013}, {16975966327722178521, 1039},
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{12648080533535911531, 1066},
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}
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)
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func find_cachedpow10(exp int64, k *int64) Fp {
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one_log_ten := 0.30102999566398114
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approx := int64(float64(-(exp + npowers)) * one_log_ten)
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idx := int((approx - firstpower) / steppowers)
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for {
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current := int(exp + powers_ten[idx].exp + 64)
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if current < expmin {
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idx++
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continue
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}
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if current > expmax {
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idx--
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continue
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}
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*k = (firstpower + int64(idx)*steppowers)
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return powers_ten[idx]
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}
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}
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