Abstract: A method to handle data dependencies in a pipelined computer system is disclosed. The method includes allocating a plurality of registers, enabling execution of computer instructions concurrently by using the plurality of registers, and tracking and reducing data dependencies in the computer instructions by correlating a busy condition of a computer instruction to each register.

Abstract: A technique to use available register cache resources if register file resources are unavailable. Embodiments of the invention pertain to a register cache writeback algorithm for storing writeback data to a register cache if register file write ports or space is unavailable.

Abstract: After an instruction loads data into a register at a first time, the register is monitored to see if it is read in a next clock cycle. When the data is not read in the next clock cycle, the instruction is classified as a slowable instruction. An instruction address associated with the instruction is used to update a history table. The history table stores information to indicate if an instruction is a slowable instruction or a non-slowable instruction. When the instruction address of the instruction is encountered at a second time, the history table is used to determine if the instruction is slowable or non-slowable.

Abstract: A mechanism, which supports predictive register cache allocation and entry, uses a counter look-up table to determine the potential significances of physical register references.

Abstract: Disclosed are an apparatus, system, and method for implementing predicated instructions using micro-operations. A micro-code engine receives an instruction, decomposes the instruction, and generates a plurality of micro-operations to implement the instruction. Each of the decomposed micro-operations indicates a single destination register. For predicated instructions, the decomposed micro-operations include “conditional move” micro-operations to select between two potential output values. Except in the case that one of the potential output values is a constant, the decomposed micro-operations for a predicated instruction also include an append instruction that saves the incoming value of a destination register in a temporary variable. For at least one embodiment, the qualifying predicate for a predicated instruction is appended to the incoming value stored in the temporary register.

Abstract: An apparatus and method are provided for renaming a logical register for which bit accesses of varying lengths are permitted, such as a predicate register. Rename logic supports renaming for both partial-bit accesses and bulk-bit accesses to bits of the register. Rename logic utilizes a rename map table associated with the logical register to be renamed and also includes a plurality of physical rename registers. They physical rename registers include a set of skinny physical rename registers to be used for renaming for partial-bit writes. The physical rename registers also include a set of fat physical rename registers to be used for renaming for bulk-bit writes. Additional sizes of physical rename registers may also be employed. The entries of the single physical rename map table may point to either fat or skinny physical rename registers.

Abstract: A method to handle data dependencies in a pipelined computer system. The method includes allocating a plurality of registers, enabling execution of computer instructions concurrently by using the plurality of registers, and tracking and reducing data dependencies in the computer instructions by correlating busy condition of a computer instruction to each register.

Abstract: After an instruction loads data into a register at a first time, the register is monitored to see if it is read in a next clock cycle. When the data is read in a next clock cycle, the instruction is classified as a slowable instruction. An instruction address associated with the instruction is used to update a history table. The history table stores information to indicate if an instruction is a slowable instruction or a non-slowable instruction. When the instruction address of the instruction is encountered at a second time, the history table is used to determine if the instruction is slowable or non-slowable.