foop
Version:
interfaces that describe their intentions.
28 lines (27 loc) • 841 B
JavaScript
/**
* v8 has an optimization for storing 31-bit signed numbers.
* Values which have either 00 or 11 as the high order bits qualify.
* This function drops the highest order bit in a signed number, maintaining
* the sign bit.
*
* @since 5.0.0-beta.6
* @version 2.0.0 <- accidentally had as signed, fixed to uint
* @memberOf cast
*
* @name toUint31
* @alias castToSigned31BitUinteger
* @alias castTo31
* @alias castToUint31
* @alias toSignedUint31
* @alias smi
*
* @param {number} i32 32bit integer
* @return {number} unsigned31Integer number
*
* {@link https://github.com/facebook/immutable-js/blob/master/src/Math.js#L22 immutablejs-tounsigned31}
* @see {@link immutablejs-tounsigned31}
*/
module.exports = function toUnsigned31(i32) {
// eslint-disable-next-line
return i32 >>> 1 & 0x40000000 | i32 & 0xbfffffff;
}