External module "number/float64/base/from-words/docs/types/index.d"

Export assignment fromWords

• fromWords(high: number, low: number): number

• Creates a double-precision floating-point number from a higher order word (unsigned 32-bit integer) and a lower order word (unsigned 32-bit integer).

  Notes

  float64 (64 bits)
  f := fraction (significand/mantissa) (52 bits)
  e := exponent (11 bits)
  s := sign bit (1 bit)
  
  |-------- -------- -------- -------- -------- -------- -------- --------|
  |                                Float64                                |
  |-------- -------- -------- -------- -------- -------- -------- --------|
  |              Uint32               |               Uint32              |
  |-------- -------- -------- -------- -------- -------- -------- --------|

  If little endian (more significant bits last):

                          <-- lower      higher -->
  |   f7       f6       f5       f4       f3       f2    e2 | f1 |s|  e1  |

  If big endian (more significant bits first):

                          <-- higher      lower -->
  |s| e1    e2 | f1     f2       f3       f4       f5        f6      f7   |

  In which Uint32 should we place the higher order bits? If little endian, the second; if big endian, the first.

  References

  • Open Group

  Parameters

  • high: number

    higher order word (unsigned 32-bit integer)

  • low: number

    lower order word (unsigned 32-bit integer)

  Returns number

  floating-point number

  Example

  var v = fromWords( 1774486211, 2479577218 );
  // returns 3.14e201

  Example

  var v = fromWords( 3221823995, 1413754136 );
  // returns -3.141592653589793

  Example

  var v = fromWords( 0, 0 );
  // returns 0.0

  Example

  var v = fromWords( 2147483648, 0 );
  // returns -0.0

  Example

  var v = fromWords( 2146959360, 0 );
  // returns NaN

  Example

  var v = fromWords( 2146435072, 0 );
  // returns Infinity

  Example

  var v = fromWords( 4293918720, 0 );
  // returns -Infinity