Saving/restoring selected registers in transactional processing

摘要

A TRANSACTION BEGIN instruction begins execution of a transaction and includes a general register save mask having bits, that when set, indicate registers to be saved in the event the transaction is aborted. At the beginning of the transaction, contents of the registers are saved in memory not accessible to the program, and if the transaction is aborted, the saved contents are copied to the registers.

主权项

1. A computer system for facilitating processing of transactions within a computing environment, said computer system comprising:
a memory; and a processor in communications with the memory, wherein the computer system is configured to perform a method, said method comprising:
obtaining a transaction begin instruction, the transaction begin instruction comprising an opcode that specifies a transaction begin instruction of a particular type, and a field that specifies a general register save mask to explicitly specify a set of individually selected registers to be saved based on executing the transaction begin instruction, the transaction begin instruction to initiate a transaction, and the general register save mask explicitly specifying the set of individually selected registers to be saved at a start of the transaction, wherein the general register save mask comprises a plurality of bits, and each bit of the plurality of bits represents an even-odd pair of registers, the transaction effectively delaying committing transactional stores to main memory until completion of a selected transaction; andexecuting the transaction begin instruction, the executing the transaction begin instruction comprising saving contents of the set of individually selected registers explicitly specified in the general register save mask of the transaction begin instruction, and initiating execution of the transaction.