try {
            System.arraycopy(this.sbuf, 0, buffer, 0, 4 + SMB1_HEADER_LENGTH);
            final int size = Encdec.dec_uint16be(buffer, 2) & 0xFFFF;
            if (size < SMB1_HEADER_LENGTH + 1 || 4 + size > Math.min(0xFFFF, getContext().getConfig().getMaximumBufferSize())) {
                throw new IOException("Invalid payload size: " + size);
            }

	ANDS	$0xffff, R2                         // ANDS	$65535, R2                      // 423c40f2
	AND	$0x7fffffff, R3                     // AND	$2147483647, R3                 // 63784092
	ANDS	$0x0ffffffff80000000, R2            // ANDS	$-2147483648, R2                // 428061f2
	AND	$0xfffff, R2                        // AND	$1048575, R2                    // 424c4092