Instructions Retired

Thread Specificity: TS

The Instructions Retired event counts the number of instructions retired. By default, this count does not include bogus instructions. In this event description, the term bogus refers to instructions that were canceled because they are on a path that should not have been taken due to a mispredicted branch.

Branch mispredictions incur a large penalty on deeply pipelined microprocessors. In general, most branches can be predicted accurately. However in the event of a misprediction, instructions that were scheduled to execute along the mispredicted path must be canceled.

Advanced: Changing what the Instructions Retired event measures

By default, for this event, the mask bits are set to count instructions that are retired during a clock cycle. You can also set the mask bits to count bogus or non-bogus instructions, and whether they are tagged via the front-end tagging mechanism as follows:

Event Mask Bits

Description

Bit 0: NBOGUSNTAG

Non-bogus instructions that are not tagged

Bit 1: NBOGUSTAG

Non-bogus instructions that are tagged

Bit 2: BOGUSNTAG

Bogus instructions that are not tagged

Bit 3: BOGUSTAG

Bogus instructions that are tagged

 

Additional Key CPI-Limiting Events