Register mapping to map architectural registers to corresponding physical registers based on a mode indicating a register length

Abstract

Mode change detection circuitry detects a mode change when processing circuitry switches between first and second modes of processing in which a first set of architectural registers are designated as having different register lengths. Register mapping circuitry maps architectural registers to corresponding physical registers. For an operation specifying a given architectural register of the first set of architectural registers: in response to a determination that the operation is to be processed in the first mode of processing, the register mapping circuitry maps the given architectural register to a physical register of a first physical register file, and in response to a determination that the operation is to be processed in the second mode of processing, the register mapping circuitry maps the given architectural register to a physical register of a second physical register file separate from the first physical register file and having physical registers of different register length to physical registers of the first physical register file.