摘要:
A pipelined processor includes circuitry adapted for store forwarding, including: for each store request, and while a write to one of a cache and a memory is pending; obtaining the most recent value for at least one block of data; merging store data from the store request with the block of data thus updating the block of data and forming a new most recent value and an updated complete block of data; and buffering the updated block of data into a store data queue; for each additional store request, where the additional store request requires at least one updated block of data: determining if store forwarding is appropriate for the additional store request on a block-by-block basis; if store forwarding is appropriate, selecting an appropriate block of data from the store data queue on a block-by-block basis; and forwarding the selected block of data to the additional store request.
摘要:
A system for data operand fetching control includes a computer processor that includes a control unit for determining memory access operations. The control unit is configured to perform a method. The method includes calculating a summation weight value for each instruction in a pipeline, the summation weight value calculated as a function of branch uncertainty and a pendency in which the instruction resides in the pipeline relative to other instructions in the pipeline. The method also includes mapping the summation weight value of a selected instruction that is attempting to access system memory to a memory access control, each memory access control specifying a manner of handling data fetching operations. The method further includes performing a memory access operation for the selected instruction based upon the mapping.
摘要:
Method and system for a multi-level virtual/real cache system with synonym resolution. An exemplary embodiment includes a multi-level cache hierarchy, including a set of L1 caches associated with one or more processor cores and a set of L2 caches, wherein the set of L1 caches are a subset of the set of L2 caches, wherein the set of L1 caches underneath a given L2 cache are associated with one or more of the processor cores.
摘要:
A pipelined microprocessor includes circuitry for store forwarding by performing: for each store request, and while a write to one of a cache and a memory is pending; obtaining the most recent value for at least one complete block of data; merging store data from the store request with the complete block of data thus updating the block of data and forming a new most recent value and an updated complete block of data; and buffering the updated complete block of data into a store data queue; for each load request, where the load request may require at least one updated completed block of data: determining if store forwarding is appropriate for the load request on a block-by-block basis; if store forwarding is appropriate, selecting an appropriate block of data from the store data queue on a block-by-block basis; and forwarding the selected block of data to the load request.
摘要:
A test method and apparatus for randomly testing logic structures. The method includes identifying and analyzing a functional behavior of a logic structure to be covered during the random testing, modifying the logic structure such that the logic structure behaves in a functional manner during random testing, and generating patterns to exercise the modified logic structure.
摘要:
Method and system for a multi-level virtual/real cache system with synonym resolution. An exemplary embodiment includes a multi-level cache hierarchy, including a set of L1 caches associated with one or more processor cores and a set of L2 caches, wherein the set of L1 caches are a subset of the set of L2 caches, wherein the set of L1 caches underneath a given L2 cache are associated with one or more of the processor cores.
摘要:
There is provided a method, system and computer program product for generating trace data related to a data processing system event. The method includes: receiving an instruction relating to the system event from a location in the system; determining a minimum number of trace segment records required to record instruction information; and creating a trace segment table including the number of trace segment records, the number of trace segment records including at least one instruction record.
摘要:
A method for handling cache coherency includes allocating a tag when a cache line is not exclusive in a data cache for a store operation, and sending the tag and an exclusive fetch for the line to coherency logic. An invalidation request is sent within a minimum amount of time to an I-cache, preferably only if it has fetched to the line and has not been invalidated since, which request includes an address to be invalidated, the tag, and an indicator specifying the line is for a PSC operation. The method further includes comparing the request address against stored addresses of prefetched instructions, and in response to a match, sending a match indicator and the tag to an LSU, within a maximum amount of time. The match indicator is timed, relative to exclusive data return, such that the LSU can discard prefetched instructions following execution of the store operation that stores to a line subject to an exclusive data return, and for which the match is indicated.
摘要:
A method for handling cache coherency includes allocating a tag when a cache line is not exclusive in a data cache for a store operation, and sending the tag and an exclusive fetch for the line to coherency logic. An invalidation request is sent within a minimum amount of time to an I-cache, preferably only if it has fetched to the line and has not been invalidated since, which request includes an address to be invalidated, the tag, and an indicator specifying the line is for a PSC operation. The method further includes comparing the request address against stored addresses of prefetched instructions, and in response to a match, sending a match indicator and the tag to an LSU, within a maximum amount of time. The match indicator is timed, relative to exclusive data return, such that the LSU can discard prefetched instructions following execution of the store operation that stores to a line subject to an exclusive data return, and for which the match is indicated.
摘要:
A read only storage (ROS) array holds a small set of relatively simple millicode instructions; those millicode instruction routines which are most commonly called on in executing common application workloads. The millicode read only store is implemented as a portion of hardware system area (HSA) storage. The cache control includes a register which contains hardware system area address corresponding to the read only store address. When an instruction fetch request is received by the cache control, the absolute address of the instruction fetch request is compared with the read only store address in the register in parallel with the normal cache directory lookup. If the instruction fetch request matches the read only store address, the fetch is made from the read only store independently of the directory lookup result.