tor-browser

The Tor Browser
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float16-rounding.js (3219B)

      1 const tests = [
      2  // Float16 subnormal numbers.
      3  {
      4    value: 2.9802322387695312e-8,
      5    f64: 0x3e60_0000_0000_0000n,
      6    f32: 0x3300_0000,
      7    f16: 0x0,
      8  },
      9  {
     10    value: 2.980232238769532e-8,
     11    f64: 0x3e60_0000_0000_0001n,
     12    f32: 0x3300_0000,
     13    f16: 0x1,
     14  },
     15 
     16  {
     17    value: 8.940696716308592e-8,
     18    f64: 0x3e77_ffff_ffff_ffffn,
     19    f32: 0x33c0_0000,
     20    f16: 0x1,
     21  },
     22  {
     23    value: 8.940696716308594e-8,
     24    f64: 0x3e78_0000_0000_0000n,
     25    f32: 0x33c0_0000,
     26    f16: 0x2,
     27  },
     28 
     29  {
     30    value: 0.000060945749282836914,
     31    f64: 0x3f0f_f400_0000_0000n,
     32    f32: 0x387f_a000,
     33    f16: 0x3fe,
     34  },
     35  {
     36    value: 0.00006094574928283692,
     37    f64: 0x3f0f_f400_0000_0001n,
     38    f32: 0x387f_a000,
     39    f16: 0x3ff,
     40  },
     41 
     42  {
     43    value: 0.0000610053539276123,
     44    f64: 0x3f0f_fbff_ffff_ffffn,
     45    f32: 0x387f_e000,
     46    f16: 0x3ff,
     47  },
     48  {
     49    value: 0.000061005353927612305,
     50    f64: 0x3f0f_fc00_0000_0000n,
     51    f32: 0x387f_e000,
     52    f16: 0x400,
     53  },
     54 
     55  // Float16 normal numbers.
     56  {
     57    value: 0.000061035154431010596,
     58    f64: 0x3f0f_ffff_f000_0000n,
     59    f32: 0x3880_0000,
     60    f16: 0x400,
     61  },
     62  {
     63    value: 0.00006103515625,
     64    f64: 0x3f10_0000_0000_0000n,
     65    f32: 0x3880_0000,
     66    f16: 0x400,
     67  },
     68  {
     69    value: 0.0000610649585723877,
     70    f64: 0x3f10_0200_0000_0000n,
     71    f32: 0x3880_1000,
     72    f16: 0x400,
     73  },
     74  {
     75    value: 0.00006106495857238771,
     76    f64: 0x3f10_0200_0000_0001n,
     77    f32: 0x3880_1000,
     78    f16: 0x401,
     79  },
     80  {
     81    value: 0.00006112456321716307,
     82    f64: 0x3f10_05ff_ffff_ffffn,
     83    f32: 0x3880_3000,
     84    f16: 0x401,
     85  },
     86 
     87  // Underflow to zero.
     88  {
     89    value: 2.980232594040899e-8,
     90    f64: 0x3e60_0000_2000_0000n,
     91    f32: 0x3300_0001,
     92    f16: 0x1,
     93  },
     94  {
     95    value: 2.9802322387695312e-8,
     96    f64: 0x3e60_0000_0000_0000n,
     97    f32: 0x3300_0000,
     98    f16: 0x0,
     99  },
    100  {
    101    value: 2.9802320611338473e-8,
    102    f64: 0x3e5f_ffff_e000_0000n,
    103    f32: 0x32ff_ffff,
    104    f16: 0x0,
    105  },
    106 
    107  // Overflow to infinity.
    108  {
    109    value: 65536,
    110    f64: 0x40f0_0000_0000_0000n,
    111    f32: 0x4780_0000,
    112    f16: 0x7c00,
    113  },
    114  {
    115    value: 65520,
    116    f64: 0x40ef_fe00_0000_0000n,
    117    f32: 0x477f_f000,
    118    f16: 0x7c00,
    119  },
    120  {
    121    value: 65504,
    122    f64: 0x40ef_fc00_0000_0000n,
    123    f32: 0x477f_e000,
    124    f16: 0x7bff,
    125  },
    126 ];
    127 
    128 const ta_f64 = new Float64Array(1);
    129 const ta_f32 = new Float32Array(1);
    130 const ta_f16 = new Float16Array(1);
    131 
    132 const ta_u64 = new BigUint64Array(ta_f64.buffer);
    133 const ta_u32 = new Uint32Array(ta_f32.buffer);
    134 const ta_u16 = new Uint16Array(ta_f16.buffer);
    135 
    136 for (let i = 0; i < 1000; ++i) {
    137  let {value, f64, f32, f16} = tests[i % tests.length];
    138 
    139  ta_f64[0] = value;
    140  assertEq(ta_u64[0], f64);
    141 
    142  ta_f32[0] = value;
    143  assertEq(ta_u32[0], f32);
    144 
    145  ta_f16[0] = value;
    146  assertEq(ta_u16[0], f16);
    147 
    148  assertEq(Math.f16round(value), ta_f16[0]);
    149 }
    150 
    151 // Test negative case.
    152 for (let i = 0; i < 1000; ++i) {
    153  let {value, f64, f32, f16} = tests[i % tests.length];
    154 
    155  value = value * -1;
    156  f64 = (f64 | 0x8000_0000_0000_0000n);
    157  f32 = (f32 | 0x8000_0000) >>> 0;
    158  f16 = (f16 | 0x8000);
    159 
    160  ta_f64[0] = value;
    161  assertEq(ta_u64[0], f64);
    162 
    163  ta_f32[0] = value;
    164  assertEq(ta_u32[0], f32);
    165 
    166  ta_f16[0] = value;
    167  assertEq(ta_u16[0], f16);
    168 
    169  assertEq(Math.f16round(value), ta_f16[0]);
    170 }