METHOD AND APPARATUS FOR MANAGING A RETURN STACK

摘要

A processor includes a return stack circuit used for predicting procedure return addresses for instruction pre-fetching, wherein a return stack controller determines the number of return levels associated with a given return instruction, and pops that number of return addresses from the return stack. Popping multiple return addresses from the return stack permits the processor to pre-fetch the return address of the original calling procedure in a chain of successive procedure calls. In one embodiment, the return stack controller reads the number of return levels from a value embedded in the return instruction. A complementary compiler calculates the return level values for given return instructions and embeds those values in them at compile-time. In another embodiment, the return stack circuit dynamically tracks the number of return levels by counting the procedure calls (branches) in a chain of successive procedure calls.