Latest producer tracking in an out-of-order processor, and applications thereof

Abstract

A processor and system for latest producer tracking. In one embodiment, the processor includes an operand renamer circuit that includes a register rename map, a producer tracking circuit that includes a producer tracking map, and a results buffer allocater circuit that includes a results buffer free list. Control logic modifies in-register status values stored in the register rename map based on producer tracking status values stored in the producer tracking map. The producer tracking status values stored in the producer tracking map are modified based on buffer identification values output by the results buffer allocater circuit.

1 . A processor, comprising:
 an operand renamer circuit that stores a plurality of in-register status values, wherein each in-register status value is associated with a particular architectural state register;   a producer tracking circuit that stores a plurality of producer tracking status values, wherein each producer tracking status value is associated with a particular physical register; and   control logic that modifies the in-register status values based on the producer tracking status values.   
     
     
         2 . The processor of  claim 1 , wherein the operand renamer circuit includes a register rename map. 
     
     
         3 . The processor of  claim 2 , wherein values stored in the register rename map are accessed using architectural state register identification values. 
     
     
         4 . The processor of  claim 1 , wherein the producer tracking circuit includes a producer tracking map. 
     
     
         5 . The processor of  claim 4 , wherein values stored in the producer tracking map are accessed using physical register identification values. 
     
     
         6 . The processor of  claim 1 , wherein each producer tracking status value consists of a single bit. 
     
     
         7 . The processor of  claim 1 , wherein the operand renamer circuit sends a signal to the producer tracking circuit to modify a particular producer tracking status value. 
     
     
         8 . The processor of  claim 1 , wherein the processor further comprises a results buffer allocater circuit, and the results buffer allocater circuit sends a signal to the producer tracking circuit to modify a particular producer tracking status value. 
     
     
         9 . A system, comprising:
 a processor that includes
 an operand renamer circuit that stores a plurality of in-register status values, wherein each in-register status value is associated with a particular architectural state register, 
 a producer tracking circuit that stores a plurality of producer tracking status values, wherein each producer tracking status value is associated with a particular physical register, and 
 control logic that modifies the in-register status values based on the producer tracking status values; and 
   memory coupled to the processor.   
     
     
         10 . The system of  claim 9 , wherein the operand renamer circuit includes a register rename map. 
     
     
         11 . The system of  claim 9 , wherein the producer tracking circuit includes a producer tracking map. 
     
     
         12 . The system of  claim 9 , wherein the operand renamer circuit sends a signal to the producer tracking circuit to modify a particular producer tracking status value. 
     
     
         13 . The system of  claim 9 , wherein the processor further comprises a results buffer allocater circuit, and the results buffer allocater circuit sends a signal to the producer tracking circuit to modify a particular producer tracking status value. 
     
     
         14 . A tangible computer readable storage medium comprising a processor embodied in software, the processor comprising:
 an operand renamer circuit that stores a plurality of in-register status values, wherein each in-register status value is associated with a particular architectural state register;   a producer tracking circuit that stores a plurality of producer tracking status values, wherein each producer tracking status value is associated with a particular physical register; and   control logic that modifies the in-register status values based on the producer tracking status values.   
     
     
         15 . The tangible computer readable storage medium of  claim 14 , wherein the operand renamer circuit includes a register rename map. 
     
     
         16 . The tangible computer readable storage medium of  claim 14 , wherein the producer tracking circuit includes a producer tracking map. 
     
     
         17 . The tangible computer readable storage medium of  claim 14 , wherein the operand renamer circuit sends a signal to the producer tracking circuit to modify a particular producer tracking status value. 
     
     
         18 . The tangible computer readable storage medium of  claim 14 , wherein the processor further comprises a results buffer allocater circuit, and the results buffer allocater circuit sends a signal to the producer tracking circuit to modify a particular producer tracking status value. 
     
     
         19 . The computer readable storage medium of  claim 14 , wherein the processor is embodied in hardware description language software. 
     
     
         20 . The computer readable storage medium of  claim 19 , wherein the processor is embodied in one of Verilog hardware description language software and VHDL hardware description language software.