Split register file for operands of different sizes

摘要

In an embodiment, a processor includes a register file having multiple widths corresponding to different operands sizes of a given data type implemented by the processor. For example, the integer register file may have 32 bit and 64 bit widths for 32 and 64 bit operand sizes. The register file may have a section of registers for each operand size, and the map unit may allocate registers from the appropriate section for each instruction operation based on the operand size of that instruction operation. The register file may consume less integrated circuit area than another register file having the same number of registers, all of which are implemented at the largest operand size. In some embodiments, only the register file and the map unit (specifically the free list management logic in the map unit) are changed to implement the multiple-width register file.

主权项

1. A processor comprising:
a register file having a first portion corresponding to a first operand size and a first data type and a second portion corresponding to a second operand size and the first data type, wherein registers in the first portion are a first width specified by the first operand size and registers in the second portion are a second width specified by the second operand size, and wherein the first operand size is different from the second operand size, and wherein the first data type defines an interpretation of data in the registers; and a map unit coupled to receive an instruction operation and configured to assign a register in the register file to a result of the instruction operation, wherein the map unit is configured to select the register from the first portion responsive to the instruction operation having the first operand size, and wherein the map unit is configured to select the register from the second portion responsive to the instruction operation having the second operand size.