| Patent application number | Description | Published |
|---|
| 20080229068 | ADAPTIVE FETCH GATING IN MULTITHREADED PROCESSORS, FETCH CONTROL AND METHOD OF CONTROLLING FETCHES - A multithreaded processor, fetch control for a multithreaded processor and a method of fetching in the multithreaded processor. Processor event and use (EU) signals are monitored for downstream pipeline conditions indicating pipeline execution thread states. Instruction cache fetches are skipped for any thread that is incapable of receiving fetched cache contents, e.g., because the thread is full or stalled. Also, consecutive fetches may be selected for the same thread, e.g., on a branch mis-predict. Thus, the processor avoids wasting power on unnecessary or place keeper fetches. | 09-18-2008 |
| 20080263321 | Universal Register Rename Mechanism for Targets of Different Instruction Types in a Microprocessor - A unified register rename mechanism for targets of different instruction types is provided in a microprocessor. The universal rename mechanism renames destinations of different instruction types using a single rename structure. Thus, an instruction that is updating a floating point register (FPR) can be renamed along with an instruction that is updating a general purpose register (GPR) or vector multimedia extensions (VMX) instructions register (VR) using the same rename structure because the number of architected states for GPR is the same as the number of architected states for FPR and VR. Each destination tag (DTAG) is assigned to one destination. A floating point instruction may be assigned to a DTAG, and then a fixed point instruction may be assigned to the next DTAG and so forth. With a universal rename mechanism, significant silicon and power can be saved by having only one rename structure for all instruction types. | 10-23-2008 |
| 20080263331 | Universal Register Rename Mechanism for Instructions with Multiple Targets in a Microprocessor - A universal register rename mechanism for instructions with multiple targets using a common destination tag. For each instruction that updates multiple destinations, a single rename entry is allocated to handle all destinations associated with it. A rename entry now consists of a DTAG and a vector to indicate the type of destination(s) that is/are being updated by such a particular instruction. For example, a common DTAG can be assigned to a fixed point unit instruction (FXU) that updates general purpose register (GPR), fixed point exception register (XER), and condition code register (CR) destinations. During flush time, the DTAGs in the recovery link may be used to restore the information indicating that the youngest instruction updates a particular architected register. By using a single, universal rename structure for all types of destinations, a large saving in silicon and power can be realized without the need to sacrifice performance. | 10-23-2008 |
| 20080313422 | Enhanced Single Threaded Execution in a Simultaneous Multithreaded Microprocessor - A method, system, and computer program product are provided for enhancing the execution of independent loads in a processing unit. The processing unit dispatches a first set of instructions in order from a first buffer for execution. The processing unit receives updated results from the execution of the first set of instructions. The processing unit updates, in a first register, at least one register entry associated with each instruction in the first set of instructions, with the updated results. The processing unit determines if the first set of instructions from the first buffer have completed execution. Responsive to the completed execution of the first set of instructions from the first buffer, the processing unit copies the set of entries from the first register to a second register. | 12-18-2008 |
| 20080313425 | Enhanced Load Lookahead Prefetch in Single Threaded Mode for a Simultaneous Multithreaded Microprocessor - A method, system, and computer program product are provided for enhancing the execution of independent loads in a processing unit. A processing unit detects if a long-latency miss associated with a load instruction has been encountered. Responsive to a long-latency miss, the processing unit enters a load lookahead mode. Responsive to entering the load lookahead mode, the processing unit dispatches each instruction from a first set of instructions from a first buffer with an associated vector. The processing unit determines if the first set of instructions from the first buffer have completed execution. Responsive to completed execution of the first set of instructions from the first buffer, the processing unit copies the set of vectors from a first vector array to a second vector array. Then the processing unit dispatches a second set of instructions from a second buffer with an associated vector from the second vector array. | 12-18-2008 |
| 20090106534 | System and Method for Implementing a Software-Supported Thread Assist Mechanism for a Microprocessor - A system and computer-implementable method for implementing software-supported thread assist within a data processing system, wherein the data processing system supports processing instructions within at least a first thread and a second thread. An instruction dispatch unit (IDU) places the first thread into a sleep mode. The IDU separates an instruction stream for the second thread into at least a first independent instruction stream and a second independent instruction stream. The first independent instruction stream is processed utilizing facilities allocated to the first thread and the second independent instruction stream is processed utilizing facilities allocated to the second thread. In response to determining a result of the processing in the first independent instruction stream requires write back to registers allocated to the second thread, the IDU sets at least one selection bit to enable selective copying of content within registers allocated to the first thread to registers allocated to the second thread. | 04-23-2009 |
| 20090106538 | System and Method for Implementing a Hardware-Supported Thread Assist Under Load Lookahead Mechanism for a Microprocessor - The present invention includes a system and method for implementing a hardware-supported thread assist under load lookahead mechanism for a microprocessor. According to an embodiment of the present invention, hardware thread-assist mode can be activated when one thread of the microprocessor is in a sleep mode. When load lookahead mode is activated, the fixed point unit copies the content of one or more architected facilities from an active thread to corresponding architected facilities in the first inactive thread. The load-store unit performs at least one speculative load in load lookahead mode and writes the results of the at least one speculative load to a duplicated architected facility in the first inactive thread. | 04-23-2009 |
| 20110283095 | Hardware Assist Thread for Increasing Code Parallelism - Mechanisms are provided for offloading a workload from a main thread to an assist thread. The mechanisms receive, in a fetch unit of a processor of the data processing system, a branch-to-assist-thread instruction of a main thread. The branch-to-assist-thread instruction informs hardware of the processor to look for an already spawned idle thread to be used as an assist thread. Hardware implemented pervasive thread control logic determines if one or more already spawned idle threads are available for use as an assist thread. The hardware implemented pervasive thread control logic selects an idle thread from the one or more already spawned idle threads if it is determined that one or more already spawned idle threads are available for use as an assist thread, to thereby provide the assist thread. In addition, the hardware implemented pervasive thread control logic offloads a portion of a workload of the main thread to the assist thread. | 11-17-2011 |
| 20110283096 | REGISTER FILE SUPPORTING TRANSACTIONAL PROCESSING - A processor includes an instruction sequencing unit, execution unit, and multi-level register file including a first level register file having a lower access latency and a second level register file having a higher access latency. Responsive to the processor processing a second instruction in a transactional code section to obtain as an execution result a second register value of the logical register, the mapper moves a first register value of the logical register to the second level register file, places the second register value in the first level register file, marks the second register value as speculative, and replaces a first mapping for the logical register with a second mapping. Responsive to unsuccessful termination of the transactional code section, the mapper designates the second register value in the first level register file as invalid so that the first register value in the second level register file becomes the working value. | 11-17-2011 |
