src/vendor/dtoa/src/lib.rs

   1 // Copyright 2016 Dtoa Developers
   2 //
   3 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   4 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   5 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   6 // option. This file may not be copied, modified, or distributed
   7 // except according to those terms.
   8
   9 #[macro_use] mod diyfp;
  10 #[macro_use] mod dtoa;
  11
  12 use std::{io, mem, ops, ptr, slice};
  13
  14 #[inline]
  15 pub fn write<W: io::Write, V: Floating>(wr: W, value: V) -> io::Result<usize> {
  16     value.write(wr)
  17 }
  18
  19 pub trait Floating {
  20     fn write<W: io::Write>(self, W) -> io::Result<usize>;
  21 }
  22
  23 impl Floating for f32 {
  24     fn write<W: io::Write>(self, wr: W) -> io::Result<usize> {
  25         dtoa! {
  26             floating_type: f32,
  27             significand_type: u32,
  28             exponent_type: i32,
  29
  30             diy_significand_size: 32,
  31             significand_size: 23,
  32             exponent_bias: 0x7F,
  33             mask_type: u32,
  34             exponent_mask: 0x7F800000,
  35             significand_mask: 0x007FFFFF,
  36             hidden_bit: 0x00800000,
  37             cached_powers_f: CACHED_POWERS_F_32,
  38             cached_powers_e: CACHED_POWERS_E_32,
  39             min_power: (-36),
  40         };
  41         unsafe { dtoa(wr, self) }
  42     }
  43 }
  44
  45 impl Floating for f64 {
  46     fn write<W: io::Write>(self, wr: W) -> io::Result<usize> {
  47         dtoa! {
  48             floating_type: f64,
  49             significand_type: u64,
  50             exponent_type: isize,
  51
  52             diy_significand_size: 64,
  53             significand_size: 52,
  54             exponent_bias: 0x3FF,
  55             mask_type: u64,
  56             exponent_mask: 0x7FF0000000000000,
  57             significand_mask: 0x000FFFFFFFFFFFFF,
  58             hidden_bit: 0x0010000000000000,
  59             cached_powers_f: CACHED_POWERS_F_64,
  60             cached_powers_e: CACHED_POWERS_E_64,
  61             min_power: (-348),
  62         };
  63         unsafe { dtoa(wr, self) }
  64     }
  65 }
  66
  67 ////////////////////////////////////////////////////////////////////////////////
  68
  69 const MAX_DECIMAL_PLACES: isize = 324;
  70
  71 static DEC_DIGITS_LUT: &'static [u8] =
  72     b"0001020304050607080910111213141516171819\
  73       2021222324252627282930313233343536373839\
  74       4041424344454647484950515253545556575859\
  75       6061626364656667686970717273747576777879\
  76       8081828384858687888990919293949596979899";
  77
  78 // 10^-36, 10^-28, ..., 10^52
  79 static CACHED_POWERS_F_32: [u32; 12] = [
  80     0xaa242499, 0xfd87b5f3, 0xbce50865, 0x8cbccc09,
  81     0xd1b71759, 0x9c400000, 0xe8d4a510, 0xad78ebc6,
  82     0x813f3979, 0xc097ce7c, 0x8f7e32ce, 0xd5d238a5,
  83 ];
  84
  85 static CACHED_POWERS_E_32: [i16; 12] = [
  86     -151, -125, -98, -71, -45, -18, 8, 35, 62, 88, 115, 141,
  87 ];
  88
  89 // 10^-348, 10^-340, ..., 10^340
  90 static CACHED_POWERS_F_64: [u64; 87] = [
  91     0xfa8fd5a0081c0288, 0xbaaee17fa23ebf76,
  92     0x8b16fb203055ac76, 0xcf42894a5dce35ea,
  93     0x9a6bb0aa55653b2d, 0xe61acf033d1a45df,
  94     0xab70fe17c79ac6ca, 0xff77b1fcbebcdc4f,
  95     0xbe5691ef416bd60c, 0x8dd01fad907ffc3c,
  96     0xd3515c2831559a83, 0x9d71ac8fada6c9b5,
  97     0xea9c227723ee8bcb, 0xaecc49914078536d,
  98     0x823c12795db6ce57, 0xc21094364dfb5637,
  99     0x9096ea6f3848984f, 0xd77485cb25823ac7,
 100     0xa086cfcd97bf97f4, 0xef340a98172aace5,
 101     0xb23867fb2a35b28e, 0x84c8d4dfd2c63f3b,
 102     0xc5dd44271ad3cdba, 0x936b9fcebb25c996,
 103     0xdbac6c247d62a584, 0xa3ab66580d5fdaf6,
 104     0xf3e2f893dec3f126, 0xb5b5ada8aaff80b8,
 105     0x87625f056c7c4a8b, 0xc9bcff6034c13053,
 106     0x964e858c91ba2655, 0xdff9772470297ebd,
 107     0xa6dfbd9fb8e5b88f, 0xf8a95fcf88747d94,
 108     0xb94470938fa89bcf, 0x8a08f0f8bf0f156b,
 109     0xcdb02555653131b6, 0x993fe2c6d07b7fac,
 110     0xe45c10c42a2b3b06, 0xaa242499697392d3,
 111     0xfd87b5f28300ca0e, 0xbce5086492111aeb,
 112     0x8cbccc096f5088cc, 0xd1b71758e219652c,
 113     0x9c40000000000000, 0xe8d4a51000000000,
 114     0xad78ebc5ac620000, 0x813f3978f8940984,
 115     0xc097ce7bc90715b3, 0x8f7e32ce7bea5c70,
 116     0xd5d238a4abe98068, 0x9f4f2726179a2245,
 117     0xed63a231d4c4fb27, 0xb0de65388cc8ada8,
 118     0x83c7088e1aab65db, 0xc45d1df942711d9a,
 119     0x924d692ca61be758, 0xda01ee641a708dea,
 120     0xa26da3999aef774a, 0xf209787bb47d6b85,
 121     0xb454e4a179dd1877, 0x865b86925b9bc5c2,
 122     0xc83553c5c8965d3d, 0x952ab45cfa97a0b3,
 123     0xde469fbd99a05fe3, 0xa59bc234db398c25,
 124     0xf6c69a72a3989f5c, 0xb7dcbf5354e9bece,
 125     0x88fcf317f22241e2, 0xcc20ce9bd35c78a5,
 126     0x98165af37b2153df, 0xe2a0b5dc971f303a,
 127     0xa8d9d1535ce3b396, 0xfb9b7cd9a4a7443c,
 128     0xbb764c4ca7a44410, 0x8bab8eefb6409c1a,
 129     0xd01fef10a657842c, 0x9b10a4e5e9913129,
 130     0xe7109bfba19c0c9d, 0xac2820d9623bf429,
 131     0x80444b5e7aa7cf85, 0xbf21e44003acdd2d,
 132     0x8e679c2f5e44ff8f, 0xd433179d9c8cb841,
 133     0x9e19db92b4e31ba9, 0xeb96bf6ebadf77d9,
 134     0xaf87023b9bf0ee6b,
 135 ];
 136 static CACHED_POWERS_E_64: [i16; 87] = [
 137     -1220, -1193, -1166, -1140, -1113, -1087, -1060, -1034, -1007,  -980,
 138     -954,   -927,  -901,  -874,  -847,  -821,  -794,  -768,  -741,  -715,
 139     -688,   -661,  -635,  -608,  -582,  -555,  -529,  -502,  -475,  -449,
 140     -422,   -396,  -369,  -343,  -316,  -289,  -263,  -236,  -210,  -183,
 141     -157,   -130,  -103,   -77,   -50,   -24,     3,    30,    56,    83,
 142      109,    136,   162,   189,   216,   242,   269,   295,   322,   348,
 143      375,    402,   428,   455,   481,   508,   534,   561,   588,   614,
 144      641,    667,   694,   720,   747,   774,   800,   827,   853,   880,
 145      907,    933,   960,   986,  1013,  1039,  1066,
 146 ];