Abstract: A storage device in a set associative system includes N-pieces (N is an integer of 2 or larger) of ways each having a plurality of entries containing at least replace flags and predetermined data, an acquisition unit acquiring the replace flags contained in the entries specified by the same address from the N-pieces of ways, and a selection unit selecting a replace target way on the basis of the replace flags acquired by the acquisition unit.

Abstract: A cache memory control unit that controls a cache memory comprises: a PF-PORT 22 and MI-PORT 21 that receive a prefetch request and demand fetch request issued from a primary cache; and a processing pipeline 27 that performs swap processing when the MI-PORT 21 receives a demand fetch request designating the same memory address as that designated by a prefetch request that has already been received by the PF-PORT 22, the swap processing being performed so that an MIB 28 that has been ensured for replying the prefetch request is used for a reply to the demand fetch request following the prefetch request.

Abstract: A cacheable memory access space receives memory access addresses having different data structures according to a status of a cache capacity from a processor. A cache hit detector determines whether data has been hit based on a mode signal, an enbblk [n] signal, and a signal indicating whether the way is valid or invalid, which are preset in the cache hit detector, a tag comparison address received from the cacheable memory access space, and a tag received from the storage unit.

Abstract: A return address in response to a return instruction corresponding to a call instruction is stored in a return address stack when a branch history detects presence of the call instruction. When the branch history detects the presence of the return instruction before a branch reservation station completes executing the call instruction, the return address in response to the return instruction is not stored in the return address stack. If so, an output selection circuit predicts a correct return target using information stored in the return address stack.

Abstract: A cache memory includes a first-level cache-memory unit that stores data; a second-level cache-memory unit that stores data that is same as the data stored in the first-level cache-memory unit; a storage unit that stores a part of information relating to the first-level cache-memory unit; and a coherence maintaining unit that maintains cache-coherence between the first-level cache-memory unit and the second-level cache-memory unit based on information stored in the storage unit.

Abstract: The present invention relates to a multithread processor. In the multithread processor, when a cache miss occurs on a request related to an instruction in, of a plurality of caches arranged hierarchically, a cache at the lowest place in the hierarchy, with respect to the request suffering the cache miss, a cache control unit notifies an instruction identifier and a thread identifier, which are related to the instruction, to a multithread control unit. When a cache miss occurs on an instruction to be next completed, the multithread control unit makes the switching between threads on the basis of the instruction identifier and thread identifier notified from the cache control unit. This enables effective thread switching, thus enhancing the processing speed.

Abstract: If a base register value, an index register value and a displacement value are given in the case of operand access, these values are inputted to an arithmetic unit to generate a correctly calculated logical address. Simultaneously, a logical address predicting unit predicts a logical address. An absolute address is predicted based on the predicted logical address by using an absolute address history table. Access to a cache memory (LBS) based on an absolute address is made using the predicted absolute address to obtain cache data. Then, the arithmetic unit calculates a correct absolute address using the correctly calculated address using a TLB and checks if the correct absolute address coincides with the predicted absolute address so as to perform result confirmation of the cache data read from the LBS. In the case of instruction fetch, similar processing is carried out except that the calculation of a logical address is not performed.

Abstract: In a data processing apparatus using a register window method performing data transmission from a master register to a work register during an exception handling, detecting a trap, discriminating whether or not a data transmission is required for the global registers by the trap, and transmitting data from the master register to the work register for only the global registers if the trap requires transmitting data for the global registers, thereby providing the data processing apparatus performing data transmission to the global registers if the occurring trap requires data for the global registers.

Abstract: An information processing apparatus is capable of speculatively performing an execution, such as a pipeline/superscalar/out-of-order execution and equipped with a branch prediction mechanism (a branch history).

Abstract: In a method for controlling a processor which accesses information of a storage device through cache memory, when reading information stored in a target address or an address range of the storage device, it is monitored whether there is an update access to the address or address range from another processor, and also the processor is entered into a suspense status, which is released using the occurrence of the update access to the storage device from another processor as a trigger.

Abstract: The multi-threading changeover control apparatus of the present invention changes over threads in an information processing device in which a multi-threading method is used, and comprises a thread changeover request unit outputting a thread changeover request signal after a cache miss occurs in which an instruction to be fetched is not stored when the instruction is fetched or a thread execution priority order change request unit outputting a thread execution priority order change request signal.

Abstract: An instruction control apparatus, and method, used with a device including a cache memory, a lower memory, an instruction fetch device issuing an instruction fetch request for a target of a first branch instruction to the cache memory, and an instruction control device processing a instruction sequence stored in the cache memory. The apparatus and method pre-prefetch a target instruction sequence for a target of a second branch instruction. A predetermined instruction sequence based on a past history is preliminarily transferred from the lower memory to the cache memory when the target instruction sequence for the target of the first branch instruction is not in the cache memory.

Abstract: An apparatus includes a branch instruction prediction unit configured to make branch prediction, and a branch prediction control unit configured to control an instruction fetch control unit, an instruction buffer, an instruction decoder, and the branch instruction prediction unit, wherein when the branch prediction control unit ascertains that the branch prediction by the branch instruction prediction unit is erroneous, the branch prediction control unit outputs to the instruction fetch control unit a signal for suppressing an instruction fetch request already supplied to the memory unit and outputs to the instruction buffer a signal for nullifying the instruction buffer during a period between a point in time at which the ascertainment is made by the branch prediction control unit that the branch prediction by the branch instruction prediction unit is erroneous and a point in time at which the instruction buffer fetches a correct instruction from the memory unit.

Abstract: A branch history information write control device in an instruction execution processing apparatus includes a memory unit storing an instruction string, and a branch prediction unit performing a branch prediction of a branch instruction. A control unit in the device controls the memory unit and the branch prediction unit in such a way that writing of branch history information in the branch prediction unit and control over fetching of the instruction string in the memory unit may not occur simultaneously so that no instruction fetch is held. A bypass unit in the device makes the branch history information of the branch instruction a research target of a branch prediction, where said control unit uses a counter to count several clock cycles (several states) to delay, for a period of several clock cycles (several states), the writing of the branch history information and control, beforehand, the fetching of the instruction string.

Abstract: An instruction control apparatus, and method, used with a device including a cache memory, a lower memory, an instruction fetch device issuing an instruction fetch request for a target of a first branch instruction to the cache memory, and an instruction control device processing a instruction sequence stored in the cache memory. The apparatus and method pre-prefetch a target instruction sequence for a target of a second branch instruction. A predetermined instruction sequence based on a past history is preliminarily transferred from the lower memory to the cache memory when the target instruction sequence for the target of the first branch instruction is not in the cache memory.

Abstract: A register number of a link register, which is specified by an instruction equivalent to a subroutine call, is registered. The number of a branch destination register in a branch instruction which can possibly be an instruction equivalent to a subroutine return is compared with the registered register number. If they match, this branch instruction is identified as an instruction equivalent to a subroutine return.

Abstract: The present invention provides a coating type reinforcement composition of sheet metal which can be applied under warming for ensuring satisfactory levels of tensile rigidity and resistance to dent of a thin sheet metal mainly due to weight reduction of an automobile body, or for collision safety, and which improve a bending strength and a rigidity of the sheet metal without causing a distortion to the sheet metal. The coating type reinforcement composition of sheet metal according to the present invention comprises a liquid epoxy resin, a latent curing agent and an inorganic filler having an aspect ratio (L/D) of 5 or higher, an amount of the inorganic filler contained being 20 to 50% by weight and the composition being a viscous preparation with a high viscosity.

Abstract: A cache memory device in an N-way (N is an integer of 2 or larger) set associative system includes a way detection unit detecting one way exhibiting a specified strength on the basis of a reference history defined as bits representing a win/loss relation between ways and updated so as to indicate one way exhibiting the specified strength, and an error detection unit detecting a bit error in the reference history if the way detection unit does not detect one way exhibiting the specified strength.

Abstract: A cache memory device comprises a secondary tag RAM that partially constitutes a secondary cache memory and employs a set associative scheme having a plurality of ways, and a secondary cache access controller that, when the number of ways in the secondary tag RAM is changed, allocates tags to respective entries so that the total number of entries constituting the secondary tag RAM and the total number of entries after the number of ways is changed are constant.

Abstract: A storage device in a set associative system includes N-pieces (N is an integer of 2 or larger) of ways each having a plurality of entries containing at least replace flags and predetermined data, an acquisition unit acquiring the replace flags contained in the entries specified by the same address from the N-pieces of ways, and a selection unit selecting a replace target way on the basis of the replace flags acquired by the acquisition unit.