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 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 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 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:
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.
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.
摘要:
A method is provided for obtaining time-of-day (“TOD”) clock records on an information processing system. In accordance with such method, a first instruction is issued for recording a TOD clock value. In response to issuing the first instruction, a truncated version of a first current TOD clock value is obtained and recorded as a first TOD clock record, the first TOD clock value being a first current TOD clock value produced by a TOD clock running continuously on the information processing system. Thereafter, a second instruction is issued. In response to issuing the second instruction, a truncated version of a second current TOD clock value is obtained and recorded as a second TOD clock record, the second current TOD clock value being produced by the TOD clock, and the second TOD clock record being permitted to have the same value as the first TOD clock record.
摘要:
A system, method and computer program product for performing a Perform Timing Facility (PTFF) instruction for steering a Time of Day (TOD) clock of the computer system for synchronizing the TOD clock with TOD clocks of other computer systems. The computer system comprises a memory; and, a processor in communications with the computer memory. The processor is capable of performing a PTFF instruction comprising: obtaining a function code specified in a first general register, the function code for identifying any one of a query function or a control function to be performed; obtaining, from a second general register, a memory address of a parameter block; responsive to the function code specifying a query function, storing timing information of the computer system in the parameter block according to the specified query function; responsive to the function code specifying a control function, using timing information obtained from the parameter block to perform the specified control function; and setting a condition code value indicating an outcome of the specified function.