Asynchronous flush and restore of distributed history buffer

A system, comprising:

• at least one processor comprising a register file and a history buffer (HB);
• and
• a memory storing a program, which, when executed on the at least one processor, perform an operation for performing a flush and restore of the HB, the operation comprising:
• identifying one or more entries of the HB to restore to the register file;
• determining, for each of the one or more HB entries, whether to send the HB entry to the register file via a first restore bus or via a second restore bus, different from the first restore bus, based on contents of the HB entry;
• and
• sending each of the one or more HB entries to the register file via one of the first restore bus or the second restore bus, based on the determination.

A computer program product, the computer program product comprising:

• a computer-readable storage medium having computer-readable program code embodied therewith, the computer-readable program code executable by one or more computer processors to perform an operation for performing a flush and restore of a history buffer (HB) in a processing unit, the operation comprising:
• identifying one or more entries of the HB to restore to a register file in the processing unit;
• determining, for each of the one or more HB entries, whether to send the HB entry to the register file via a first restore bus or via a second restore bus, different from the first restore bus, based on contents of the HB entry;
• and
• sending each of the one or more HB entries to the register file via one of the first restore bus or the second restore bus, based on the determination.