摘要:
A method is disclosed for selecting data in a computer system having a cache memory and a branch history table, where the method includes predicting an address corresponding to the data, selecting data at the predicted address in the cache memory, translating an address corresponding to the data, comparing the translated address with the predicted address, and if they are different, re-selecting data at the translated address in the cache memory and appending the translated address to the branch history table.
摘要:
A method of supporting programs that include instructions that modify subsequent instructions in a multi-processor system with a central processing unit including an execution unit, and instruction unit and a plurality of caches including a separate instruction and operand cache.
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.
摘要:
A method is disclosed for instructing a computing system to ensure that a line is present in an instruction cache that includes selecting a line-touch instruction, recognizing the line-touch instruction as a type of branch instruction where the branch is not taken, executing the line-touch instruction to fetch a target line from a target address into the instruction cache, and interlocking the execution of the line-touch instruction with the completion of the fetch of the target line in order to prevent execution of the instruction following the line-touch instruction until after the target line has reached the cache.
摘要:
A method and system for detecting address generation interlock in a pipelined data processor is disclosed. The method comprises accumulating a plurality of vectors over a predefined number of processor clock cycles, with subsequent vectors corresponding to subsequent clock cycles; accumulating the status of one or more general registers in the plurality of vectors with the same bit location in each vector of the plurality of vectors corresponding to a particular general register; generating a list of pending general register updates from a logical combination of the plurality of vectors; and determining the existence of address generation interlock from the list of pending general register updates.
摘要:
Two forms of TOD Clock instructions are provided, Store Clock and Store Clock Fast. Execution of the Store Clock Fast instruction may produce a time of day (TOD) result that is exactly the same as a previous TOD result, however execution of Store Clock Fast instructions while the clock is running always produce unique TOD results.
摘要:
In a computer system with multiple chips connected via a connection module with high speed elastic interface buses that support bus repair is enhanced by use of a spare net. Support is provided to ensure that the spare net can be tested in the same way that every normal bus net can be tested at all supported environments. It ensure that the system controller can find out what connections are bad and how to apply the controls to repair them for all tests and in the field for the customer.
摘要:
A system and method to re-fetch operand data lost for instructions with operands greater than eight bytes in length due to line invalidation due to storage update from a single or plurality of processors in a multiprocessor computer system using microprocessors that perform out of order operand fetch with respect to sequential program order in which it is not possible or desirable to kill the execution of the instruction when the storage access rules require that it appear that the operand data is accessed in program execution order.
摘要:
An embodiment of the invention is a processor for providing simultaneous access to the same data for a plurality of requests. The processor includes cache storage having an address sliced directory lookup structure. A same doubleword detection unit receives a first instruction including a plurality of first instruction fields on a first pipe and a second instruction including a plurality of second instruction fields on a second pipe. The same doubleword detection unit generates a same doubleword signal in response to the first instruction fields and the second instruction fields. The cache storage reads data from a single doubleword in the cache storage and simultaneously provides the doubleword to the first pipe and the second pipe in response to the same doubleword signal.
摘要:
A system, method and computer program product for steering a time-of-day (TOD) clock for a computer system having a physical clock providing a time base for executing operations that is stepped to a common oscillator. The method includes receiving, at a processing unit, a request to change a clock steering rate used to control a TOD-clock offset value for the processing unit, the TOD-clock offset defined as a function of a start time (s), a base offset (b), and a steering rate (r). The unit schedules a next episode start time with which to update the TOD-clock offset value. After updating TOD-clock offset value (d) at the scheduled time, TOD-clock offset value is added to a physical-clock value (Tr) value to obtain a logical TOD-clock value (Tb), where the logical TOD-clock value is adjustable without adjusting a stepping rate of the oscillator.