Method mul

projects/JavaScript/proto/int64.js:615–686

* Multiply this value with other one * @this {!Int64} * @param {!Int64|!UInt64|number|string} other Other value * @returns {!Int64} Multiplication of two values

(other)

   * @returns {!Int64} Multiplication of two values
   */
  mul (other) {
    if (this.isZero) {
      return INT64_ZERO
    }
    if (!Int64.isInt64(other) && !UInt64.isUInt64(other)) {
      other = Int64.fromValue(other)
    }

    if (other.isZero) {
      return INT64_ZERO
    }
    if (this.eq(INT64_MIN)) {
      return other.isOdd ? INT64_MIN : INT64_ZERO
    }
    if (other.eq(INT64_MIN)) {
      return this.isOdd ? INT64_MIN : INT64_ZERO
    }

    if (this.isNegative) {
      if (other.isNegative) {
        return this.neg().mul(other.neg())
      } else {
        return this.neg().mul(other).neg()
      }
    } else if (other.isNegative) {
      return this.mul(other.neg()).neg()
    }

    // If both longs are small, use float multiplication
    if (this.lt(INT64_TWO_PWR_24) && other.lt(INT64_TWO_PWR_24)) {
      return Int64.fromNumber(this.toNumber() * other.toNumber())
    }

    // Divide each long into 4 chunks of 16 bits, and then add up 4x4 products.
    // We can skip products that would overflow.

    let a48 = this.high >>> 16
    let a32 = this.high & 0xFFFF
    let a16 = this.low >>> 16
    let a00 = this.low & 0xFFFF

    let b48 = other.high >>> 16
    let b32 = other.high & 0xFFFF
    let b16 = other.low >>> 16
    let b00 = other.low & 0xFFFF

    let c48 = 0
    let c32 = 0
    let c16 = 0
    let c00 = 0
    c00 += a00 * b00
    c16 += c00 >>> 16
    c00 &= 0xFFFF
    c16 += a16 * b00
    c32 += c16 >>> 16
    c16 &= 0xFFFF
    c16 += a00 * b16
    c32 += c16 >>> 16