Method and apparatus for providing early bypass detection to reduce power consumption while reading register files of a processor

• Main Authors: VENKATARAMANAN GANESH, TALPES EMIL
• Format: Patent
• Language: English
• Published: 27.10.2015
• Subjects: CALCULATING; CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION ANDCOMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION ANDCOMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THIR OWNENERGY USE; COMPUTING; COUNTING; ELECTRIC DIGITAL DATA PROCESSING; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; PHYSICS; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE

A method and apparatus are described for reducing power consumption in a processor. A micro-operation is selected for execution, and a destination physical register tag of the selected micro-operation is compared to a plurality of source physical register tags of micro-operations dependent upon the selected micro-operation. If there is a match between the destination physical register tag and one of the source physical register tags, a corresponding physical register file (PRF) read operation is disabled. The comparison may be performed by a wakeup content-addressable memory (CAM) of a scheduler. The wakeup CAM may send a read control signal to the PRF to disable the read operation. Disabling the corresponding PRF read operation may include shutting off power in the PRF and related logic.