Function rotateModulo

ext/src/llvm/APInt.cpp:1056–1066

Calculate the rotate amount modulo the bit width.

// Calculate the rotate amount modulo the bit width.
static unsigned rotateModulo(unsigned BitWidth, const APInt &rotateAmt) {
  unsigned rotBitWidth = rotateAmt.getBitWidth();
  APInt rot = rotateAmt;
  if (rotBitWidth < BitWidth) {
    // Extend the rotate APInt, so that the urem doesn't divide by 0.
    // e.g. APInt(1, 32) would give APInt(1, 0).
    rot = rotateAmt.zext(BitWidth);
  }
  rot = rot.urem(APInt(rot.getBitWidth(), BitWidth));
  return rot.getLimitedValue(BitWidth);
}

APInt APInt::rotl(const APInt &rotateAmt) const {
  return rotl(rotateModulo(BitWidth, rotateAmt));