Patent ID: 8356162

Claim:
A method of executing an instruction in an execution unit, the method comprising, in response to receiving a data dependent conditional write instruction: testing data associated with the data dependent conditional write instruction against a condition associated with the data dependent conditional write instruction; and selectively writing to a target associated with the data dependent conditional write instruction based upon the test; wherein testing the data against the condition includes determining that the condition is not met, and wherein selectively writing to the target comprises, in response to determining the condition is not met: in a first stage of a multi-stage execution pipeline in the execution unit that is executing the data dependent conditional write instruction, deasserting a write enable signal based upon the determination that the condition is not met; and in a second, subsequent stage of the multi-stage execution pipeline, writing to the target while the write enable signal is not asserted such that the target is not updated in response to the write; wherein the data dependent conditional write instruction includes an operand that identifies the data against which the condition is tested, wherein testing the data against the condition includes testing the data identified by the operand, wherein the operand is a first operand that identifies a first register, wherein the data dependent conditional write instruction includes a second operand that identifies a second register, and wherein testing the data against the condition includes comparing data stored in the first register with data stored in the second register.