Abstract: Embodiments include various methods, apparatuses, and systems in which a processor includes an out of order issue engine and an in-order execution pipeline. For some embodiments, the issue engine may be remote from the execution pipeline and execution resources may be many clock cycles away from the issue engine The issue engine categorizes operations as at least one of either a speculative operation, which perform computations, or an architectural operation, which has potential to fault or cause an exception. Potentially excepting operations may be decomposed into two separate micro-operations: a speculative micro-operation, which is used to generate data results speculatively so that operations dependent on the results may be speculatively issued, and an architectural micro-operation, which signals the faulting condition for the excepting operation. A STORE operation becomes an architectural operation and all previous faulting conditions may be guaranteed to have evaluated before a STORE is issued.

Abstract: Briefly, a method and apparatus of branch prediction is provided. The branch prediction may be done by performing a XOR operation between MSB of set bits of a path register with LSB of set bits of an instruction pointer address register to provide a global index, and by performing a XOR operation of LSB tag bits of the path register with MSB tag bits of the instruction pointer address register and providing a tag index. There may be multiplexing between a global prediction to a local prediction.

Abstract: A register renaming system for out-of-order execution of a set of reduced instruction set computer instructions having addressable source and destination register fields, adapted for use in a computer having an instruction execution unit with a register file accessed by read address ports and for storing instruction operands. A data dependance check circuit is included for determining data dependencies between the instructions. A tag assignment circuit generates one or more tags to specify the location of operands, based on the data dependencies determined by the data dependance check circuit. A set of register file port multiplexers select the tags generated by the tag assignment circuit and pass the tags onto the read address ports of the register file for storing execution results.

Abstract: A tag monitoring system for assigning tags to instructions. A source supplies instructions to be executed by a functional unit. A register file stores information required for the execution of each instruction. A queue having a plurality of slots containing tags which are used for tagging the instructions. The tags are arranged in the queue in an order specified by the program order of their corresponding instructions. A control unit monitors the completion of executed instructions and advances the tags in the queue upon completion of an executed instruction. The register file stores an instruction's information at a location in the register file defined by the tag assigned to that instruction. The register file also contains a plurality of read address enable ports and corresponding read output ports. Each of the slots from the queue is coupled to a corresponding one of the read address enable ports. Thus, the information for each instruction can be read out of the register file in program order.

Abstract: The high-performance, RISC core based microprocessor architecture includes an instruction fetch unit for fetching instruction sets from an instruction store and an execution unit that implements the concurrent execution of a plurality of instructions through a parallel array of functional units. The fetch unit generally maintains a predetermined number of instructions in an instruction buffer. The execution unit includes an instruction selection unit, coupled to the instruction buffer, for selecting instructions for execution, and a plurality of functional units for performing instruction specified functional operations. A unified instruction scheduler, within the instruction selection unit, initiates the processing of instructions through the functional units when instructions are determined to be available for execution and for which at least one of the functional units implementing a necessary computational function is available.

Abstract: A processor system and method that reduces the number of register value copying made from alias registers to corresponding real (architectural) registers. One method entails not performing an alias register to real register copying if the incoming instruction does not designate a real register. Another method entails delaying alias register to real register copying until the corresponding reorder buffer (ROB) entry is actually written to. Yet another method entails not performing an alias register to real register copying if the ROB entry is the same as the existing ROB entry. And, still another method entails further delaying or stalling the allocation of an ROB entry.

Abstract: A multi-streaming processor has a plurality of streams for streaming one or more instruction threads, a set of functional resources for processing instructions from streams, and interrupt handler logic. The logic detects and maps interrupts and exceptions to one or more specific streams. In some embodiments one interrupt or exception may be mapped to two or more streams, and in others two or more interrupts or exceptions may be mapped to one stream. Mapping may be static and determined at processor design, programmable, with data stored and amendable, or conditional and dynamic, the interrupt logic executing an algorithm sensitive to variables to determine the mapping. Interrupts may be external interrupts generated by devices external to the processor software (internal) interrupts generated by active streams, or conditional, based on variables. After interrupts are acknowledged streams to which interrupts or exceptions are mapped are vectored to appropriate service routines.

Abstract: In an information processing device including a processing circuit that performs processing in synchronization with a clock, and a clock supply control circuit that controls supply of the clock to the processing circuit, the number of cycles required from start of execution of processing in the processing circuit until output of a result of the processing is extracted, the extracted number of cycles is transferred to the clock supply control circuit, the supply of the clock is started when the processing is started in the processing circuit, and the supply of the clock to the processing circuit is stopped when the supply of the clock with the number of cycles is completed. Thus, a clock control method and an information processing device employing the clock control method are provided that allow power consumption to be reduced without impairing an execution efficiency of pipeline processing.

Abstract: The present invention provides a system and method for managing load and store operations necessary for reading from and writing to memory or I/O in a superscalar RISC architecture environment. To perform this task, a load store unit is provided whose main purpose is to make load requests out of order whenever possible to get the load data back for use by an instruction execution unit as quickly as possible. A load operation can only be performed out of order if there are no address collisions and no write pendings. An address collision occurs when a read is requested at a memory location where an older instruction will be writing. Write pending refers to the case where an older instruction requests a store operation, but the store address has not yet been calculated. The data cache unit returns 8 bytes of unaligned data. The load/store unit aligns this data properly before it is returned to the instruction execution unit.

Abstract: Processing restrictions of a computing environment are filtered and blocked, in certain circumstances, such that processing continues despite the restrictions. One restriction includes an indication that fetching of storage keys is prohibited, in response to a buffer miss. When a processing unit of the computing environment is met with this restriction, it performs a comparison of addresses, which indicates whether the fetching can continue. If fetching can continue, the restriction is ignored.

Abstract: A time multiplex changing function for priorities among threads is added to a multi-thread processor, and capability for large-scale out-of-order execution is achieved by confining the flows of data among threads, prescribing the execution order in the flow sequence, and executing a plurality of threads having data dependency either simultaneously or in time multiplex.

Abstract: The present invention provides a system and method for managing load and store operations necessary for reading from and writing to memory or I/O in a superscalar RISC architecture environment. To perform this task, a load store unit is provided whose main purpose is to make load requests out of order whenever possible to get the load data back for use by an instruction execution unit as quickly as possible. A load operation can only be performed out of order if there are no address collisions and no write pendings. An address collision occurs when a read is requested at a memory location where an older instruction will be writing. Write pending refers to the case where an older instruction requests a store operation, but the store address has not yet been calculated. The data cache unit returns 8 bytes of unaligned data. The load/store unit aligns this data properly before it is returned to the instruction execution unit.

Abstract: A high-performance, superscalar-based computer system with out-of-order instruction execution for enhanced resource utilization and performance throughput. The computer system fetches a plurality of fixed length instructions with a specified, sequential program order (in-order). The computer system includes an instruction execution unit including a register file, a plurality of functional units, and an instruction control unit for examining the instructions and scheduling the instructions for out-of-order execution by the functional units. The register file includes a set of temporary data registers that are utilized by the instruction execution control unit to receive data results generated by the functional units. The data results of each executed instruction are stored in the temporary data registers until all prior instructions have been executed, thereby retiring the executed instruction in-order.

Abstract: The present invention provides a system and method for managing load and store operations necessary for reading from and writing to memory or I/O in a superscalar RISC architecture environment. To perform this task, a load store unit is provided whose main purpose is to make load requests out of order whenever possible to get the load data back for use by an instruction execution unit as quickly as possible. A load operation can only be performed out of order if there are no address collisions and no write pendings. An address collision occurs when a read is requested at a memory location where an older instruction will be writing. Write pending refers to the case where an older instruction requests a store operation, but the store address has not yet been calculated. The data cache unit returns 8 bytes of unaligned data. The load/store unit aligns this data properly before it is returned to the instruction execution unit.

Abstract: A system and method for extracting complex, variable length computer instructions from a stream of complex instructions each subdivided into a variable number of instructions bytes, and aligning instruction bytes of individual ones of the complex instructions. The system receives a portion of the stream of complex instructions and extracts a first set of instruction bytes starting with the first instruction bytes, using an extract shifter. The set of instruction bytes are then passed to an align latch where they are aligned and output to a next instruction detector. The next instruction detector determines the end of the first instruction based on said set of instruction bytes. An extract shifter is used to extract and provide the next set of instruction bytes to an align shifter which aligns and outputs the next instruction. The process is then repeated for the remaining instruction bytes in the stream of complex instructions.

Abstract: A high-performance, superscalar-based computer system with out-of-order instruction execution for enhanced resource utilization and performance throughput. The computer system fetches a plurality of fixed length instructions with a specified, sequential program order (in-order). The computer system includes an instruction execution unit including a register file, a plurality of functional units, and an instruction control unit for examining the instructions and scheduling the instructions for out-of-order execution by the functional units. The register file includes a set of temporary data registers that are utilized by the instruction execution control unit to receive data results generated by the functional units. The data results of each executed instruction are stored in the temporary data registers until all prior instructions have been executed, thereby retiring the executed instruction in-order.

Abstract: A high-performance, superscalar-based computer system with out-of-order instruction execution for enhanced resource utilization and performance throughput. The computer system fetches a plurality of fixed length instructions with a specified, sequential program order (in-order). The computer system includes an instruction execution unit including a register file, a plurality of functional units, and an instruction control unit for examining the instructions and scheduling the instructions for out-of-order execution by the functional units. The register file includes a set of temporary data registers that are utilized by the instruction execution control unit to receive data results generated by the functional units. The data results of each executed instruction are stored in the temporary data registers until all prior instructions have been executed, thereby retiring the executed instruction in-order.

Abstract: An out-of-order issue mechanism for a data processing system allows two out-of-order instructions to be issued to independent “pipes” from a window of four instructions currently queued for execution. If the two pipes execute floating pipe operations, dependencies between a computationally intensive floating point unit instruction (referred to as an fpu rr instruction) and the two previous computational intensive instructions having a target and a floating point register (the “fpr target”) are tracked to provide a mechanism that quickly determines when dependent data is available from one of the floating point unit pipes. The data is then used to preempt the issue of a dependent instruction until data is available. Additionally, this out-of-order issue mechanism recognizes when consecutive instructions are dependent upon a same operand.

Abstract: A method and apparatus to execute data speculative instructions in a processor comprising at least one source register, each source register comprising a bit to indicate validity of data in the at least one source register. A data validity circuit coupled to the one or more source registers to determine the validity of the data in the source registers, and to indicate the validity of the data in a destination register based upon the validity bit in the at least one source register. The processor optionally comprising a checker unit to retire those instructions from the execution unit which write valid data to the destination register, and to re-schedules those instructions for execution which write invalid data to the destination register.

Abstract: A high-performance, superscalar-based computer system with out-of-order instruction execution for enhanced resource utilization and performance throughput. The computer system fetches a plurality of fixed length instructions with a specified, sequential program order (in-order). The computer system includes an instruction execution unit including a register file, a plurality of functional units, and an instruction control unit for examining the instructions and scheduling the instructions for out-of-order execution by the functional units. The register file includes a set of temporary data registers that are utilized by the instruction execution control unit to receive data results generated by the functional units. The data results of each executed instruction are stored in the temporary data registers until all prior instructions have been executed, thereby retiring the executed instruction in-order.

Abstract: A multiple dispatch processor has several instruction fetch units, each for providing a stream of instructions to an instruction decode and dispatch unit. The processor also has an resource allocation unit, and multiple resources such as combined integer and address execution pipelines and floating point execution pipelines. Each instruction decode and dispatch unit requests resources needed to perform an instruction of the resource allocation unit, which arbitrates among the multiple instruction decode and dispatch units.

Abstract: Techniques are provided for retiring instructions that typically complete early as compared to most instructions. In an embodiment, all instructions are processed normally until the instruction queue is full. At that time, the system is frozen, e.g., all units stop processing instructions. For each instruction in the instruction queue, if the instruction meets the criteria for early retirement, then the instruction is terminated and the system is updated to reflect that the instruction has been terminated. The system is then unfrozen, and all units resume their functions.

Abstract: A superscalar processor having a content addressable memory structure that transmits a first and second output signal is presented. The superscalar processor performs out of order processing on an instruction set. From the first output signal, the dependencies between currently fetched instructions of the instruction set and previous in-flight instructions can be determined and used to generate a dependency matrix for all in-flight instructions. From the second output signal, the physical register addresses of the data required to execute an instruction, once the dependencies have been removed, may be determined.

Abstract: A processor core for realizing efficient operation processing by connecting an extended arithmetic unit to its exterior and a processor incorporating such a processing core are provided. The processor includes the processor core, a data memory accessed by the processor core, and the extended arithmetic unit connected to the exterior of the processor core for processing a particular instruction. The extended arithmetic unit executes an arithmetic operation by using arithmetic operation data retained in a register file in the processor core, and directly outputs an arithmetic operation result to the processor core. Then, the processor core saves the result of the arithmetic operation executed by the extended arithmetic unit and inputted therefrom in the register file in the processor core.

Abstract: An improved method and system for operating an out of order processor at a high frequency enabled by an increased pipeline length. It is proposed to shorten the pipeline by a considerable number of stages by accepting that a write after read conflict may occur, when directly after renaming, during the “read ROB” pipeline stage, all the information (tag, validity and data) is read from an Reorder Buffer ROB entry, and is next written, in a following pipeline stage “write RS”, into a reservation station (RS) entry. In order to assure the correctness of processing in particular in cases of dependencies, e.g., write after read conflicts a separate inventional add in logic covers these cases. The logic detects the write after read conflict case of an Instructional Execution Unit (IEU) writing into the particular entry that is selected by the renaming logic during “read ROB”.

Abstract: A circuit is provided to provide instruction streams to a processing device: embodiments of the circuit are appropriate for use with RISC CPUs, whereas other embodiments are useable with other processing devices, such as small processing devices used in a field programmable array. The circuit receives an external instruction stream which provides a first set of instruction values, and has a memory which contains a second set of instruction values. Two or more outputs provide instruction streams to the processing device. The circuit has a control input in the form of a mask which causes a selection means to allocate bits from the first and second sets of instruction values to different instruction streams to the processing device.

Abstract: A technique for producing a test executable in a computer. The technique involves forming multiple instruction streams. The technique further involves dividing the multiple instruction streams into portions, and generating a combined instruction stream having the portions interleaved. Additionally, the technique involves creating a test executable from the combined instruction stream. The test executable can be used for testing a simulated processor in a computer. In particular, the test executable is loaded. Then, the test executable is run through the simulated processor to generate processor results and through a reference model to generate reference results. The processor results and the reference results are compared to determine whether the simulated processor operates correctly.

Abstract: A pipelined microprocessor for processing instructions includes at least one pipeline. The pipeline includes and instruction fetching functional stage, an instruction decoding functional stage, an execution functional stage comprising a number of execution units and a commit functional stage. The commit functional stage includes or is associated with a reorder buffer. Detecting means are provided for detecting instruction irregularities. When an instruction irregularity is detected, an irregularity indication and a flush instruction are generated. The irregularity indication is used to initiate a flush made whereas the flush instruction, when received in a stage or unit set in flush mode, resets the flush mode in said stage/unit.

Abstract: A tag monitoring system for assigning tags to instructions. A source supplies instructions to be executed by a functional unit. A register file stores information required for the execution of each instruction. A queue having a plurality of slots containing tags which are used for tagging the instructions. The tags are arranged in the queue in an order specified by the program order of their corresponding instructions. A control unit monitors the completion of executed instructions and advances the tags in the queue upon completion of an executed instruction. The register file stores an instruction's information at a location in the register file defined by the tag assigned to that instruction. The register file also contains a plurality of read address enable ports and corresponding read output ports. Each of the slots from the queue is coupled to a corresponding one of the read address enable ports. Thus, the information for each instruction can be read out of the register file in program order.

Abstract: A method and computer graphics system capable of implementing multiple pipelines for the parallel processing of graphics data. For certain data, a requirement may exist that the data be processed in order. The graphics system may use a set of tokens to reliably switch between ordered and unordered data modes. Furthermore, the graphics system may be capable of super-sampling and performing real-time convolution. In one embodiment, the computer graphics system may comprise a graphics processor, a sample buffer, and a sample-to-pixel calculation unit. The graphics processor may be configured to receive graphics data and to generate a plurality of samples for each of a plurality of frames. The sample buffer, which is coupled to the graphics processor, may be configured to store the samples. The sample-to-pixel calculation unit is programmable to generate a plurality of output pixels by filtering the rendered samples using a filter.

Abstract: An objective is to provide a microcomputer, electronic equipment and emulation method which can realize the optimum circumstance of evaluation while saving the number of terminals. An external bus is shared between external and emulation memories. In the emulation mode, the access of CPU to an internal ROM is switched to the access of CPU to the emulation memory through an external bus. The emulation mode is turned ON or OFF through a mode selection terminal or mode selection register. The emulation memory is controlled by a control signal CNT2 different from a control signal CNT1 which controls the external memory. A memory read signal in CNT2 become active at a timing earlier than that of a memory read signal in CNT1. Thus, the instruction is fetched and decoded within one clock cycle. A mode selection terminal is further provided for selecting a mode of performing the boot from the emulation memory, internal ROM or external memory and a made of selecting OPT mode.

Abstract: A processor with instructions to operate on different data types stored in a single logical register file. According to one aspect of the invention, a first set of instructions of a first instruction type operates on the contents of what at least logically appears to software as a single logical register file. The first set of instructions appears to access the single logical register file as a flat register file. In addition, a first instruction of a second instruction type operates on the logical register file. However, the first instruction appears to access the logical register file as a stack referenced register file. Furthermore, sometime between starting the execution of the first set of instructions and completing the execution of the first instruction, all tags in a set of tags indicating whether corresponding registers in the single logical register file are empty or non-empty are caused to indicate non-empty states.

Abstract: A multi-streaming processor has a plurality of streams for streaming one or more instruction threads, a set of functional resources for processing instructions from streams; and interstream control mechanisms whereby any stream may effect the operation of any other stream. In various embodiments the interstream control mechanisms include mechanisms for accomplishing one or more of enabling or disabling another stream, putting another stream into a sleep mode or awakening another stream from a sleep mode, setting priorities for another stream relative to access to functional resources, and granting blocking access by another stream to functional resources. A Master Mode is taught, wherein one stream is granted master status, and thereby may exert any and all available control mechanisms relative to other streams without interference by any stream.

Abstract: Mapping circuitry (40) comprises a first candidate output value producing unit (42) which produces a first candidate output value (C1) that differs by a first offset value (x) from a received input value (r). A second candidate output value producing unit (44) operates, during operation of the first candidate output value producing unit (42) to produce the first candidate output value (C1), to produce a second candidate output value (C2) that differs by a second offset value (y) from the received input value (r). The first and second offset values (x, y) are such that a difference between them is equal to a difference between respective output-range limit values defining the limits of a preselected range of allowable values, and such that, for any input value (r) within a preselected range of allowable input values, one of the first and second candidate output values (C1, C2) is within the preselected output-value range and the other of those two values is outside that range.

Abstract: Method and apparatus for reducing or eliminating retirement logic in an out-of-order processor are disclosed. Instructions are processed using a processing unit capable of out-of-order processing and having architectural registers having an architectural state. Groups of instructions are prepared for processing by processing unit, wherein within each group to be processed the instructions producing the final state of an architectural register are changed so that they write to an output copy of the architectural state, the instructions reading architectural registers are changed to read from an input copy of the architectural state, and the instructions within each group producing results to architectural registers that would be overwritten by another instruction in the group are changed to write their results to temporary registers.

Abstract: An instruction issuing device comprises a plurality of issue controlling circuits which run in parallel, and perform a control for preferentially issuing an instruction to a particular arithmetic unit. An optimum issue controlling circuit is selected according to the empty quantity of instruction slots for each arithmetic unit or a result of learning of the number of previously issued instructions, and an issue destination is determined based on the direction of the selected circuit.

Abstract: A tag monitoring system for assigning tags to instructions. A source supplies instructions to be executed by a functional unit. A register file stores information required for the execution of each instruction. A queue having a plurality of slots containing tags which are used for tagging the instructions. The tags are arranged in the queue in an order specified by the program order of their corresponding instructions. A control unit monitors the completion of executed instructions and advances the tags in the queue upon completion of an executed instruction. The register file stores an instruction's information at a location in the register file defined by the tag assigned to that instruction. The register file also contains a plurality of read address enable ports and corresponding read output ports. Each of the slots from the queue is coupled to a corresponding one of the read address enable ports. Thus, the information for each instruction can be read out of the register file in program order.

Abstract: A processor comprising a new architectural feature called a Register Domain, where a Register Domain has a register file, at least one execution unit, and coupling circuitry between the two. A processor will typically have a plurality of Register Domains, and Register Domains may have different types of execution units within them. Individual Register Domains will be visible to a user.

Abstract: A method (and structure) for modeling the timing of production and consumption of data produced and consumed by instructions on a processor using irregular pipeline and/or bypass structures, includes developing a port-based look-up table containing a delay compensation number for pairs of ports in at least one of an irregular pipeline and an irregular bypass structure. Each delay compensation number permits a calculation of an earliest/latest time an instruction can be scheduled.

Abstract: A process for packing an instruction word including providing a word value representing an instruction word into which an operation is to be fit be equal to some initial value having a plurality of portions representing constraints, operating on the initial value of the value word with operation class values having a plurality of portions representing constraints of a new operation as the new operation is attempted to be fit into the instruction to affect the processor word value in a manner to indicate when the limit of any constraint for the instruction is reached, and determining a violation of any constraint to determine that the new operation does not fit the format.

Abstract: An apparatus that provides configurable processing includes a fetch module, a decoder, and a dynamic arithmetic unit. The fetch module is operable to fetch at least one instruction and provide it to the decoder. The decoder receives the instruction and decodes it. The dynamic arithmetic logic unit receives the decoded instruction and configures at least one configurable arithmetic logic unit to perform an operation contained within the decoded instruction.

Abstract: A load is executed speculatively as a dismissible load instruction, which does not take exceptions, and a check instruction, which is in the same format as the dismissible load, that when executed determines whether an exception should be taken on the dismissible load. In this manner, a load may be executed speculatively while ensuring that an exception occurs at the same time it would have occurred had the load been executed non-speculatively.

Abstract: A data processing system having a distributed reservation station is provided which stores basic blocks of code in the form of microprocessor instructions. The present invention is capable of distributing basic blocks of code to the various distributed reservation stations. Due to the smaller number of entries in the distributed reservation stations, the look up time required to find a particular instruction is much less than in a centralized reservation station. Additional instruction level parallelism is achieved by maintaining single basic blocks of code in the distributed reservation stations. With a distributed reservation station, an independent scheduler can be used for each one of the distributed reservation stations. When the instruction is ready for execution, the scheduler will remove that instruction from the distributed reservation station and queue that instruction(s) for immediate execution at the particular execution unit.

Abstract: A processing engine 10 for executing instructions in parallel comprises an instruction buffer 600 for holding at least two instructions, with the first instruction 602 in a first position and the second instruction 604 in a second position. A first decoder 612 provides decoding of the first instruction and generates first control signals. The first control signals include first resource control signals, first address generation control signals, and a first validity signal indicative of the validity of the first instruction in the first position. A second decoder 614 provides decoding of the second instruction and generates second control signals. The second control signals include second resource control signals, second address generation control signals, and a second validity signal indicative of the validity of the second instruction in the second position.

Abstract: According to one aspect of the invention, a microprocessor is provided that includes an execution core, a first replay mechanism and a second replay mechanism. The execution core performs data speculation in executing a first instruction. The first replay mechanism is used to replay the first instruction via a first replay path if an error of a first type is detected which indicates that the data speculation is erroneous. The second replay mechanism is used to replay the first instruction via a second replay path if an error of a second type is detected which indicates that the data speculation is erroneous.

Abstract: The present invention provides a system and method for managing load and store operations necessary for reading from and writing to memory or I/O in a superscalar RISC architecture environment. To perform this task, a load/store unit is provided whose main purpose is to make load requests out-of-order whenever possible to get the load data back for use by an instruction execution unit as quickly as possible. A load operation can only be performed out-of-order if there are no address collisions and no write pendings. An address collision occurs when a read is requested at a memory location where an older instruction will be writing. Write pending refers to the case where an older instruction requests a store operation, but the store address has not yet been calculated. The data cache unit returns 8 bytes of unaligned data. The load/store unit aligns this data properly before it is returned to the instruction execution unit.

Abstract: Instructions asserted in a microprocessors instruction pipeline (3) are accompanied by control information, comprising a group of bits, asserted within a control information pipeline (5) that is synchronized to the instruction pipeline. At the execution stage, the control information is interpreted and appropriate action taken. The control information may indicate that the instruction has been reasserted (asserted again following an initial assertion) and may also indicate the number of times that the instruction has been consecutively asserted in the instruction pipeline. Applied to unaligned memory operations, in which a memory atom is asserted twice, the control information indicates which part of the unaligned data is to be fetched each time the atom is executed.

Abstract: A digital signal processor (DSP) includes dual SIMD units that are connected in cascade, and wherein results of a first SIMD stage of the cascade may be stored in a register file of a second SIMD stage in the cascade. Each SIMD stage contains its own resources for storing operands and intermediate results (e.g., its own register file), as well as for decoding the operations that may be executed in that stage. Within each stage, hardware resources are organized to operate in SIMD manner, so that independent SIMD operations can be executed simultaneously, one in each stage of the cascade. Intermediate operands and results flowing through the cascade are stored at the register files of the stages, and may be accessed from those register files. Data may also be brought from memory directly into the register files of the stages in the cascade.

Abstract: An apparatus is presented for expediting the execution of address-dependent micro instructions in a pipeline microprocessor. The apparatus computes a speculative result associated with an arithmetic operation, where the arithmetic operation is prescribed by a preceding micro instruction that is yet to generate a result. The apparatus utilizes the speculative result to configure a speculative address operand that is provided to an address-dependent micro instruction. The apparatus includes speculative operand calculation logic and an update forwarding cache. The speculative operand calculation logic performs the arithmetic operation to generate the speculative result prior to when execute logic executes the preceding micro instruction to generate the result.

Abstract: The present invention relates to a method and system for providing a load with conditional fault instruction that includes an associated conditional operator, which enables load operations to be advanced above program branches by the compiler without causing unwarranted fault conditions. Specifically, the load instruction can be executed out of normal program order to enable information to be retrieved from memory before the information is needed, to permit the retrieved information to begin to be used before the conditional operator can be evaluated. Likewise, a dynamically scheduled processor can advance components of the instruction and further improve performance without having faults effect the normal program flow. The load instruction can stop the use of the information and replace the information with a predetermined, generally deterministic, value if the conditional operator indicates a faulty load operation.