External module "number/float64/base/set-high-word/docs/types/index.d"

Export assignment setHighWord

• setHighWord(x: number, high: number): number

• Sets the more significant 32 bits of a double-precision floating-point number.

  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 can we find the higher order bits? If little endian, the second; if big endian, the first.

  References

  • Open Group

  Parameters

  • x: number

    double

  • high: number

    unsigned 32-bit integer to replace the higher order word of x

  Returns number

  double having the same lower order word as x

  Example

  var high = 5 >>> 0; // => 0 00000000000 00000000000000000101
  
  var y = setHighWord( 3.14e201, high ); //  => 0 00000000000 0000000000000000010110010011110010110101100010000010
  // returns 1.18350528745e-313

  Example

  var PINF = require( `@stdlib/constants/float64/pinf` ); // => 0 11111111111 00000000000000000000 00000000000000000000000000000000
  
  var high = 1072693248 >>> 0; // => 0 01111111111 00000000000000000000
  
  // Set the higher order bits of `+infinity` to return `1`:
  var y = setHighWord( PINF, high ); // => 0 01111111111 0000000000000000000000000000000000000000000000000000
  // returns 1.0