Integer overflow wrapping for Javascript (for browsers that can optimize double to integer)

Overflow.js

const IntMask = 0xFFFFFFFF;

function iadd(a, b) {
  return ((a & IntMask) + (b & IntMask)) & IntMask;
}

function isubt(a, b) {
  return iadd(a, -b);
}

function imul(a, b) {
  return Math.imul(a, b);
}

function idiv(a, b) {
  a = +a; b = +b;
  if (!Number.isFinite(a)) throw Error("Expected finite number, got a =" + a);
  if (!Number.isFinite(b)) throw Error("Expected finite number, got b =" + b);
  if (b == 0) throw Error("Division by zero.");
  return ((a & IntMask) / (b & IntMask)) & IntMask;  
}