Abstract: A computing device and a method of allocating vector register files in a simultaneously-multithreaded (SMT) processor core are provided. A request for a first number (M) of vector register files is received from a borrower thread of the processor core. One or more available donor threads of the processor core are identified. A second number (N) of the vector register files, of the identified one or more available donor threads, are assigned to the borrower thread, where N is ?M. The borrower thread is parameterized to create a virtualized vector register file for the borrower thread, based on a width of the N vector register files of the identified one or more donor threads.

Abstract: Techniques are described for optimizing memory management in a processor system. The techniques may be implemented on processors that include on-chip performance monitoring and on systems where an external performance monitor is coupled to a processor. Processors that include a Performance Monitoring Unit (PMU) are examples. The PMU may store data on read and write cache misses, as well as data on translation lookaside buffer (TLB) misses. The data from the PMU is used to determine if any memory regions within a memory heap are delinquent memory regions, i.e., regions exhibiting high numbers of memory problems or stalls. If delinquent memory regions are found, the memory manager, such as a garbage collection routine, can efficiently optimize memory performance as well as the mutators performance by improving the layout of objects in the heap. In this way, memory management routines may be focused based on dynamic and real-time memory performance data.

Abstract: An information processing system includes a branch target buffer (BTF) comprising the last next address for the instruction and for receiving an indirect instruction address and providing a BTB predicted target; and next branch target table (NBTT) for storing potential branch targets based on a history of the branch and for providing an NBTT when the a BTB predicted target is not successful. In another embodiment a system comprising a plurality of branch prediction resources dynamically predicts the best resource appropriate for a branch. The method includes predicting a target branch for an indirect instruction address using a resource chosen among the plurality of branch prediction resources; and selectively inhibiting updates of the branch prediction resources whose prediction accuracy does not meet a threshold.

Abstract: Techniques are described for optimizing memory management in a processor system. The techniques may be implemented on processors that include on-chip performance monitoring and on systems where an external performance monitor is coupled to a processor. Processors that include a Performance Monitoring Unit (PMU) are examples. The PMU may store data on read and write cache misses, as well as data on translation lookaside buffer (TLB) misses. The data from the PMU is used to determine if any memory regions within a memory heap are delinquent memory regions, i.e., regions exhibiting high numbers of memory problems or stalls. If delinquent memory regions are found, the memory manager, such as a garbage collection routine, can efficiently optimize memory performance as well as the mutators performance by improving the layout of objects in the heap. In this way, memory management routines may be focused based on dynamic and real-time memory performance data.

Abstract: Methods and apparatus to dynamically insert prefetch instructions are disclosed. In an example method, one or more samples associated with cache misses are identified from a performance monitoring unit in a processor system. Based on sample information associated with the one or more samples, delinquent information is generated. To dynamically insert one or more prefetch instructions, a prefetch point is identified based on the delinquent information.

Abstract: Methods and apparatus to insert prefetch instructions based on garbage collector analysis and compiler analysis are disclosed. In an example method, one or more batches of samples associated with cache misses from a performance monitoring unit in a processor system are received. One or more samples from the one or more batches of samples based on delinquent information are selected. A performance impact indicator associated with the one or more samples is generated. Based on the performance indicator, at least one of a garbage collector analysis and a compiler analysis is initiated to identify one or more delinquent paths. Based on the at least one of the garbage collector analysis and the compiler analysis, one or more prefetch points to insert prefetch instructions are identified.

Abstract: According to an embodiment of the invention, a method and apparatus are described for memory trace buffering. An embodiment of a processor includes an execution unit and a buffer. The buffer is to store certain data regarding each memory operation of a plurality of memory operations that are executed by the processor.

Abstract: A compiler technique uses profile feedback to determine stride values for memory references, allowing prefetching of instructions for those loads that can be effectively prefetched. The compiler first identifies a set of loads, and instruments the loads to profile the difference between the successive load addresses in the current iteration and in the previous iteration. The frequency of stride difference is also profiled to allow the compiler to insert prefetching instructions for loads with near-constant strides. The compiler employs code analysis to determine the best prefetching distance, to reduce the profiling cost, and to reduce the prefetching overhead.