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

Export assignment setLowWord

• setLowWord(x: number, low: number): number

• Sets the less 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 lower order bits? If little endian, the first; if big endian, the second.

  References

  • Open Group

  Parameters

  • x: number

    double

  • low: number

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

  Returns number

  double having the same higher order word as x

  Example

  var low = 5 >>> 0; // => 00000000000000000000000000000101
  
  var x = 3.14e201; // => 0 11010011100 01001000001011000011 10010011110010110101100010000010
  
  var y = setLowWord( x, low ); // => 0 11010011100 01001000001011000011 00000000000000000000000000000101
  // returns 3.139998651394392e+201

  Example

  var PINF = require( `@stdlib/constants/float64/pinf` );
  var NINF = require( `@stdlib/constants/float64/ninf` );
  
  var low = 12345678;
  
  var y = setLowWord( PINF, low );
  // returns NaN
  
  y = setLowWord( NINF, low );
  // returns NaN
  
  y = setLowWord( NaN, low );
  // returns NaN