Arm Limited

Quentin Éric Nouvel

Luca Nassi

Albin Pierrick Tonnerre

Geoffray Lacourba

Adrien Pesle

Nicola Piano

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.

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

There is provided an apparatus, method for data processing. The apparatus comprises post decode cracking circuitry responsive to receipt of decoded instructions from decode circuitry of a processing pipeline, to crack the decoded instructions into micro-operations to be processed by processing circuitry of the processing pipeline. The post decode cracking circuitry is responsive to receipt of a decoded instruction suitable for cracking into a plurality of micro-operations including at least one pair of micro-operations having a producer-consumer data dependency, to generate the plurality of micro-operations including a producer micro-operation and a consumer micro-operation, and to assign a transfer register to transfer data between the producer micro-operation and the consumer micro-operation.

Cracking instructions into a plurality of micro-operations

A data processing apparatus comprises: execution circuitry to execute instructions in order to perform data processing operations specified by those instructions; a plurality of registers to store data values for access by the execution circuitry when performing the data processing operations, each register having an associated physical register identifier; register rename circuitry to select physical register identifiers to associate with architectural register identifiers specified by the instructions; and rename storage having a plurality of entries, each entry being associated with one of the architectural register identifiers and used by the register rename circuitry to indicate a physical register identifier selected for association with that one of the architectural register identifiers; the register rename circuitry comprising an execute unit, and being responsive to detection of an early execute condition for a given instruction, the early execute condition requiring at least detection that each source value required to execute the given instruction is available to the register rename circuitry without accessing the plurality of registers, to cause the execute unit to perform the data processing operation specified by the given instruction in order to generate a result value, and to cause the generated result value to be stored in an entry of the rename storage associated with a destination architectural register identifier specified by the given instruction.

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Antibes, France

Quentin Éric Nouvel