Abstract: A data processor (10) has a BTAC (48) storing a number of recently encountered fetch address-target address pairs. A branch unit (20) generates a fetch address that depends upon a condition precedent and a received branch instruction. After executing each branch instruction, the branch unit predicts whether the condition precedent will be met the next time it encounters the same branch instruction. If the predicted value of the condition precedent would cause the branch to be taken, then the branch unit adds the fetch address-target address pair corresponding to the branch instruction to the BTAC. If the predicted value of the condition precedent would cause the branch to be not taken, then the branch unit deletes the fetch address-target address pair corresponding to the branch instruction from the BTAC.

Abstract: A data processor has a plurality of execution units (12), a rename buffer (14) coupled to at least one of the execution units and a plurality of architectural registers (16) coupled to at least one execution unit and to the rename buffer. The rename buffer periodically receives and stores the result and periodically receives requests for the operand. Each received result and operand is associated with an architectural register. The rename buffer periodically forwards one of a set of received results to an execution unit. Each received result of the set is associated with the same architectural register. The rename buffer is operable to determine which entry is the most recently allocated among several that will update the same architectural register. This ability to both manage results destined for the same architectural register and to forward only the appropriate value increases data processor throughput and reduces instruction stalls.

Abstract: A circuit for use in conjunction with a multiplier receives a portion of completed product bits and a portion of sum and carry bits which, when accumulated, provide a complete output product operand. The circuit is adaptable for use with input operands having single or double precision data formats. The accumulation time required depends upon which data format mode the circuit is operating in.