How the Language Environment enclave return code is calculated

When an enclave terminates, Language Environment provides a Language Environment enclave return code and an enclave reason code (sometimes called a return code modifier). The Language Environment enclave return code is calculated by summing the user return code generated by the HLL (see Setting and altering user return codes) and the enclave reason code (see How the enclave reason code is calculated) as follows:
Language Environment enclave return code = user return code + enclave reason code

The Language Environment enclave return code is placed in register 15, and the enclave reason code is placed in register 0.