Abstract: A central processing unit includes a register file having a plurality of read ports, a first execution unit having a first plurality of input ports, and logic operable to selectively couple different arrangements of the read ports to the input ports. A method for reading operands from a register file having a plurality of read ports by a first execution unit having a first plurality of input ports includes scheduling an instruction for execution by the first execution unit and selectively coupling a particular arrangement of the read ports to the input ports based on a type of the instruction.

Abstract: A system may comprise an optimizer/scheduler to schedule on a set of instructions, compute a data dependence, a checking constraint and/or an anti-checking constraint for the set of scheduled instructions, and allocate alias registers for the set of scheduled instructions based on the data dependence, the checking constraint and/or the anti-checking constraint. In one embodiment, the optimizer is to release unused registers to reduce the alias registers used to protect the scheduled instructions. The optimizer is further to insert a dummy instruction after a fused instruction to break cycles in the checking and anti-checking constraints.

Abstract: Methods, systems, and computer program products may provide delay-identification in data processing systems. An apparatus may include a delay-identification unit having a delay counter, a threshold register, a delay register, and a delay detector. The delay detector may be configured to start the delay counter in response to detecting that one group of instructions is delayed, and stop the delay counter in response to detecting that the one group of instructions is no longer delayed. The delay detector may additionally be configured to compare the number of cycles counted by the delay counter with a threshold number of cycles in the threshold register, and store at least one effective address of one of the instructions of the one group of instructions when the number of cycles counted by the delay counter is greater than the threshold number of cycles stored in the threshold register.

Abstract: There is a need to provide a microcomputer capable of eliminating an external terminal for endian selection. Flash memory includes a user boot area for storing a program executed in user boot mode and corresponding endian information and a user area for storing a program executed in user mode and corresponding endian information. A data transfer circuit reads endian information stored in the user boot area or the user area in accordance with operation mode and supplies the endian information to a CPU before reset release of the CPU. Accordingly, an external terminal for endian selection can be eliminated.

Abstract: A multi-threaded microprocessor for processing instructions in single threaded mode and multithreaded modes. The microprocessor includes instruction dependency scoreboards, instruction input coupling circuits for selectively feeding the first and second instruction dependency scoreboards; output coupling logic having first and second instruction issue outputs; first and second execute pipelines respectively coupled to the instruction issue outputs, the first execute pipeline for executing a first program thread and the second execute pipeline for executing a second program thread, independent of the first program thread; and a control logic circuit for causing dual issue of instructions from the first program thread, by the first dependency scoreboard, to both the first execute pipeline and said second execute pipeline.

Abstract: Provided is an information processing device including an instruction cache, a data cache, first and second arithmetic unit groups including a plurality of arithmetic units capable of parallel operation, a first arithmetic-control circuit that generates one or more operation instructions for the first arithmetic unit group, and a second arithmetic-control circuit that generates one or more operation instructions for the second arithmetic unit group based on an instruction code of a fixed instruction register. The first arithmetic unit group sets the instruction code to the fixed instruction register according to an operation instruction generated based on a first specific instruction code by the first arithmetic-control circuit, and provides data to the second arithmetic unit group according to an operation instruction generated based on a second specific instruction code by the first arithmetic-control circuit.

Abstract: A free list in processor includes multiple banks for indicating availability of register identifiers used for register renaming. A register rename unit receives one or more destination architectural registers to rename with physical register identifiers. Responsive to determining the multiple banks within the free list are unbalanced with available physical register identifiers, one or more returning physical register identifiers are assigned to the destination architectural registers before assigning any physical register identifiers from any bank of the multiple banks with a lowest number of available physical register identifiers. A returning physical register identifier is a physical register identifier that is available again for assignment to a destination architectural register but not yet indicated in the free list as available. Each of the banks includes a single bit width decoded vector for indicating availability of given physical register identifiers.

Abstract: An instruction compressing apparatus and method for a parallel processing computer such as a very long instruction word (VLIW) computer, are provided. The instruction compressing apparatus includes a bundle code generating unit, an instruction compressing unit, and an instruction converting unit. The bundle code generating unit may generate a bundle code in response to an input of instructions to be compressed. The bundle code may indicate whether a current instruction group is terminated, and also whether an instruction group following the current instruction group is a no-operation (NOP) instruction group. The instruction compressing unit may remove a NOP instruction and/or a NOP instruction group from the input instructions according to the generated bundle code. The instruction converting unit may include the generated bundle code in the remaining instructions which have not been removed by the instruction compressing unit.

Abstract: An apparatus and method for avoiding bubbles and maintaining a maximum instruction throughput rate when cracking microcode instructions. A lookahead pointer scans the newest entries of a dispatch queue for microcode instructions. A detected microcode instruction is conveyed to a microcode engine to be cracked into a sequence of micro-ops. Then, the sequence of micro-ops is placed in a queue, and when the original microcode instruction entry in the dispatch queue is selected for dispatch, the sequence of micro-ops is dispatched to the next stage of the processor pipeline.

Abstract: Embodiments of an apparatus including a first processor core having a local agent running thereon, the agent comprising a local process and a proxy agent and a second processor core having a remote agent running thereon, the remote agent being an instance of the local agent. A shared memory wherein coupled to the first processor core and the second processor core, wherein the local agent and the remote agent communicate via the shared memory. Other embodiments are disclosed and claimed.

Abstract: Techniques and structures are disclosed relating to predicting return addresses in multithreaded processors. In one embodiment, a processor is disclosed that includes a return address prediction unit. The return address prediction unit is configured to store return addresses for different ones of a plurality of threads executable on the processor. The return address prediction unit is configured to receive a request for a predicted return address for one of the plurality of threads. The first request includes an identification of the requesting thread. The return address prediction unit is configured to provide the predicted return address to the requesting thread. In some embodiments, the return address prediction unit is configured to store the return addresses in a memory that has a plurality of dedicated portions. In some embodiments, the return address prediction unit is configured to store the return addresses in a memory that has dynamically allocable entries.

Abstract: The data processing apparatus (and method) has processing circuitry for performing data processing operations in response to data processing instructions, the data processing instructions referencing logical registers. A set of physical registers are provided for storing data values for access by the processing circuitry when performing the data processing operations. Register renaming storage stores a one-to-one mapping between the logical registers and the physical registers, with the register renaming storage being accessed by the processing circuitry when performing the data processing operations in order to map the referenced logical registers to corresponding physical registers. Update circuitry is arranged to identify the physical registers corresponding to those multiple logical registers in the register renaming storage. Altered one-to-one mapping between multiple logical registers and identified physical registers is employed when performing the current data processing operation.

Abstract: A method and circuit arrangement speculatively preprocess data stored in a register file during otherwise unused cycles in an execution unit, e.g., to prenormalize denormal floating point values stored in a floating point register file, to decompress compressed values stored in a register file, to decrypt encrypted values stored in a register file, or to otherwise preprocess data that is stored in an unprocessed form in a register file.

Abstract: A shared resource multi-thread processor array wherein an array of heterogeneous function blocks are interconnected via a self-routing switch fabric, in which the individual function blocks have an associated switch port address. Each switch output port comprises a FIFO style memory that implements a plurality of separate queues. Thread queue empty flags are grouped using programmable circuit means to form self-synchronised threads. Data from different threads are passed to the various addressable function blocks in a predefined sequence in order to implement the desired function. The separate port queues allows data from different threads to share the same hardware resources and the reconfiguration of switch fabric addresses further enables the formation of different data-paths allowing the array to be configured for use in various applications.

Abstract: A reconfigurable processor for efficiently performing a vector operation, and a method of controlling the reconfigurable processor are provided. The reconfigurable processor designates at least one of a plurality of processing elements as a vector lane based on vector lane configuration information, and allocates a vector operation to the designated vector lane.

Abstract: Methods and apparatuses for managing load-store dependencies in an out-of-order processor. A load store dependency predictor may include a table for storing entries for load-store pairs that have been found to be dependent and execute out of order. Each entry in the table includes a counter to indicate a strength of the dependency prediction. If the counter is above a threshold, a dependency is enforced for the load-store pair. If the counter is below the threshold, the dependency is not enforced for the load-store pair. When a store is dispatched, the table is searched, and any matching entries in the table are armed. If a load is dispatched, matches on an armed entry, and the counter is above the threshold, then the load will wait to issue until the corresponding store issues.

Abstract: A microcomputer includes: a plurality of register lists having a plurality of register patterns, respectively, wherein each of plurality of register patterns designates registers, data of which are to be saved in a data memory; an instruction fetch control circuit configured to fetch instruction code from an instruction memory in response to an interrupt request issued based on occurrence of an interrupt factor; and a register data saving control circuit configured to acquire one register pattern from one of the plurality of register lists in response to the interrupt request, and issue a microinstruction based on the acquired register pattern in response to the interrupt request. An instruction executing section is configured to execute the microinstruction prior to the fetched instruction code, to save the data of registers designated based on the acquired register pattern in the data memory.

Abstract: A vector data access unit includes data access ordering circuitry, for issuing data access requests indicated by elements of earlier and a later vector instructions, one being a write instruction. An element indicating the next data access for each of the instructions is determined. The next data accesses for the earlier and the later instructions may be reordered. The next data access of the earlier instruction is selected if the position of the earlier instruction's next data element is less than or equal to the position of the later instruction's next data element minus a predetermined value. The next data access of the later instruction may be selected if the position of the earlier instruction's next data element is higher than the position of the later instruction's next data element minus a predetermined value. Thus data accesses from earlier and later instructions are partially interleaved.

Abstract: Techniques for reducing issue-to-issue latency by reversing processing order in half-pumped single instruction multiple data (SIMD) execution units are described. In one embodiment a processor functional unit is provided comprising a frontend unit, and execution core unit, a backend unit, an execution order control signal unit, a first interconnect coupled between and output and an input of the execution core unit and a second interconnect coupled between an output of the backend unit and an input of the frontend unit. In operation, the execution order control signal unit generates a forwarding order control signal based on the parity of an applied clock signal on reception of a first vector instruction. This control signal is in turn used to selectively forward first and second portions of an execution result of the first vector instruction via the interconnects for use in the execution of a dependent second vector instruction.

Abstract: A microcomputer includes: a plurality of register lists having a plurality of register patterns, respectively, wherein each of plurality of register patterns designates registers, data of which are to be saved in a data memory; an instruction fetch control circuit configured to fetch instruction code from an instruction memory in response to an interrupt request issued based on occurrence of an interrupt factor; and a register data saving control circuit configured to acquire one register pattern from one of the plurality of register lists in response to the interrupt request, and issue a microinstruction based on the acquired register pattern in response to the interrupt request. An instruction executing section is configured to execute the microinstruction prior to the fetched instruction code, to save the data of registers designated based on the acquired register pattern in the data memory.