Abstract: A compressing instruction queue for a microprocessor including a storage queue and a redirect logic circuit. The storage queue includes a matrix of storage locations including N rows and M columns for storing microinstructions of the microprocessor in sequential order. The redirect logic circuit is configured to receive and write multiple microinstructions per cycle of a clock signal into sequential storage locations of the storage queue without leaving unused storage locations and beginning at a first available storage location in the storage queue. The redirect logic circuit performs redirection and compression to eliminate empty locations or holes in the storage queue and to reduce the number of write ports interfaced with each storage location of the storage queue.

Abstract: A processor performs out-of-order execution of a first instruction and a second instruction after the first instruction in program order, the first instruction includes source and destination indicators, the source indicator specifies a source of data, the destination indicator specifies a destination of the data, the first instruction instructs the processor to move the data from the source to the destination, the second instruction specifies a source indicator that specifies a source of data. A rename unit updates the second instruction source indicator with the first instruction source indicator if there are no intervening instructions that write to the source or to the destination of the first instruction and the second instruction source indicator matches the first instruction destination indicator.

Abstract: A compressing instruction queue for a microprocessor including a queue and redirect logic. The queue includes a matrix of storage locations including N rows and M columns for storing microinstructions of the microprocessor in sequential order. The redirect logic is configured to receive and write multiple microinstructions per cycle of a clock signal into sequential storage locations of the queue without leaving unused storage locations and beginning at a first available storage location in the queue. The redirect logic performs redirection and compression to eliminate empty locations or holes in the queue and to reduce the number of write ports interfaced with each storage location of the queue.

Abstract: A processor performs out-of-order execution of a first instruction and a second instruction after the first instruction in program order, the first instruction includes source and destination indicators, the source indicator specifies a source of data, the destination indicator specifies a destination of the data, the first instruction instructs the processor to move the data from the source to the destination, the second instruction specifies a source indicator that specifies a source of data. A rename unit updates the second instruction source indicator with the first instruction source indicator if there are no intervening instructions that write to the source or to the destination of the first instruction and the second instruction source indicator matches the first instruction destination indicator.

Abstract: An out-of-order execution microprocessor for reducing the likelihood of having to replay a load instruction due to a store collision. The microprocessor includes a queue of entries, each entry configured to hold information that identifies sources of a store instruction used to compute its store address and to hold a dependency that identifies an instruction upon which the store instruction depends for its data. A register alias table (RAT), coupled to the queue of entries, is configured to encounter instructions in program order and to generate dependencies used to determine when the instructions may execute out of program order. In response to encountering a load instruction the RAT determines whether sources of the load instruction used to compute its load address match the sources of the store instruction in an entry of the queue, and if so, causes the load instruction to share the dependency of the matching store instruction.

Abstract: An out-of-order execution microprocessor for reducing load instruction replay likelihood due to store collisions. A register alias table (RAT) is coupled to first and second queues of entries and generates dependencies used to determine when instructions may execute out of order. The RAT allocates an entry of the first queue and populates the allocated entry with an instruction pointer of a load instruction, when it determines that the load instruction must be replayed. The RAT allocates an entry of the second queue when it encounters a store instruction and populates the allocated entry with a dependency that identifies an instruction upon which the store instruction depends for its data. The RAT causes a subsequent instance of the load instruction to share the dependency when it encounters the subsequent instance of the load instruction and determines that its instruction pointer matches the instruction pointer of an entry of the first queue.

Abstract: An out-of-order execution microprocessor includes a register alias table configured to generate a first indicator that indicates whether an instruction is dependent upon a condition code result of a shift instruction. The microprocessor also includes a first execution unit configured to execute the shift instruction and to generate a second indicator that indicates whether a shift amount of the shift instruction is zero. The microprocessor also includes a second execution unit configured to receive the first and second indicators and to generate a replay signal to cause the instruction to be replayed if the first indicator indicates the instruction is dependent upon the condition code result of the shift instruction and a second indicator indicates the shift amount of the shift instruction is zero.

Abstract: An out-of-order execution microprocessor includes a register alias table configured to generate a first indicator that indicates whether an instruction is dependent upon a condition code result of a shift instruction. The microprocessor also includes a first execution unit configured to execute the shift instruction and to generate a second indicator that indicates whether a shift amount of the shift instruction is zero. The microprocessor also includes a second execution unit configured to receive the first and second indicators and to generate a replay signal to cause the instruction to be replayed if the first indicator indicates the instruction is dependent upon the condition code result of the shift instruction and a second indicator indicates the shift amount of the shift instruction is zero.

Abstract: An out-of-order execution microprocessor for reducing load instruction replay likelihood due to store collisions. A register alias table (RAT) is coupled to first and second queues of entries and generates dependencies used to determine when instructions may execute out of order. The RAT allocates an entry of the first queue and populates the allocated entry with an instruction pointer of a load instruction, when it determines that the load instruction must be replayed. The RAT allocates an entry of the second queue when it encounters a store instruction and populates the allocated entry with a dependency that identifies an instruction upon which the store instruction depends for its data. The RAT causes a subsequent instance of the load instruction to share the dependency when it encounters the subsequent instance of the load instruction and determines that its instruction pointer matches the instruction pointer of an entry of the first queue.

Abstract: An out-of-order execution microprocessor for reducing the likelihood of having to replay a load instruction due to a store collision. The microprocessor includes a queue of entries, each entry configured to hold information that identifies sources of a store instruction used to compute its store address and to hold a dependency that identifies an instruction upon which the store instruction depends for its data. A register alias table (RAT), coupled to the queue of entries, is configured to encounter instructions in program order and to generate dependencies used to determine when the instructions may execute out of program order. In response to encountering a load instruction the RAT determines whether sources of the load instruction used to compute its load address match the sources of the store instruction in an entry of the queue, and if so, causes the load instruction to share the dependency of the matching store instruction.

Abstract: An out-of-order execution microprocessor for reducing the likelihood of having to replay a load instruction due to a store collision. The microprocessor includes a queue of entries, each entry configured to hold an instruction pointer of a load instruction and to hold information useable to identify a store instruction that caused the load instruction to be replayed on a first instance of the load instruction. A register alias table (RAT) encounters instructions in program order and generates dependencies used to determine when the instructions may execute out of program order. The RAT encounters the load instruction on a second instance, determines that the load instruction second instance instruction pointer matches the instruction pointer of an entry of the queue, and causes the load instruction on the second instance to have a dependency on the store instruction identified by the information in the matching entry.