Abstract: An apparatus and method are described for performing efficient gather operations in a pipelined processor. For example, a processor according to one embodiment of the invention comprises: gather setup logic to execute one or more gather setup operations in anticipation of one or more gather operations, the gather setup operations to determine one or more addresses of vector data elements to be gathered by the gather operations; and gather logic to execute the one or more gather operations to gather the vector data elements using the one or more addresses determined by the gather setup operations.

Abstract: Disclosed herein is a generational thread scheduler. One embodiment may be used with processor multithreading logic to execute threads of executable instructions, and a shared resource to be allocated fairly among the threads of executable instructions contending for access to the shared resource. Generational thread scheduling logic may allocate the shared resource efficiently and fairly by granting a first requesting thread access to the shared resource allocating a reservation for the shared resource to each other requesting thread of the executing threads and then blocking the first thread from re-requesting the shared resource until every other thread that has been allocated a reservation, has been granted access to the shared resource. Generation tracking state may be cleared when each requesting thread of the generation that was allocated a reservation has had their request satisfied.

Abstract: Disclosed herein is a generational thread scheduler. One embodiment may be used with processor multithreading logic to execute threads of executable instructions, and a shared resource to be allocated fairly among the threads of executable instructions contending for access to the shared resource. Generational thread scheduling logic may allocate the shared resource efficiently and fairly by granting a first requesting thread access to the shared resource allocating a reservation for the shared resource to each other requesting thread of the executing threads and then blocking the first thread from re-requesting the shared resource until every other thread that has been allocated a reservation, has been granted access to the shared resource. Generation tracking state may be cleared when each requesting thread of the generation that was allocated a reservation has had their request satisfied.

Abstract: In a multi-threaded processor, thread priority variables are set up in memory. The actual assignment of thread priority is based on the expiration of a thread precedence counter. To further augment, the effectiveness of the thread precedence counters, starting counters are associated with each thread that serve as a multiplier for the value to be used in the thread precedence counter. The value in the starting counters are manipulated so as to prevent one thread from getting undue priority to the resources of the multi-threaded processor.

Abstract: An apparatus and method are described for performing efficient gather operations in a pipelined processor. For example, a processor according to one embodiment of the invention comprises: gather setup logic to execute one or more gather setup operations in anticipation of one or more gather operations, the gather setup operations to determine one or more addresses of vector data elements to be gathered by the gather operations; and gather logic to execute the one or more gather operations to gather the vector data elements using the one or more addresses determined by the gather setup operations.

Abstract: Disclosed herein is a generational thread scheduler. One embodiment may be used with processor multithreading logic to execute threads of executable instructions, and a shared resource to be allocated fairly among the threads of executable instructions contending for access to the shared resource. Generational thread scheduling logic may allocate the shared resource efficiently and fairly by granting a first requesting thread access to the shared resource allocating a reservation for the shared resource to each other requesting thread of the executing threads and then blocking the first thread from re-requesting the shared resource until every other thread that has been allocated a reservation, has been granted access to the shared resource. Generation tracking state may be cleared when each requesting thread of the generation that was allocated a reservation has had their request satisfied.

Abstract: A processor including a first execution core section clocked to perform execution operations at a first clock frequency, and a second execution core section clocked to perform execution operations at a second clock frequency which is different than the first clock frequency. The second execution core section runs faster and includes a data cache and critical ALU functions, while the first execution core section includes latency-tolerant functions such as instruction fetch and decode units and non-critical ALU functions. The processor may further include an I/O ring which may be still slower than the first execution core section. Optionally, the first execution core section may include a third execution core section whose clock rate is between that of the first and second execution core sections. Clock multipliers/dividers may be used between the various sections to derive their clocks from a single source, such as the I/O clock.

Abstract: In a multi-threaded processor, thread priority variables are set up in memory. The actual assignment of thread priority is based on the expiration of a thread precedence counter. To further augment, the effectiveness of the thread precedence counters, starting counters are associated with each thread that serve as a multiplier for the value to be used in the thread precedence counter. The value in the starting counters are manipulated so as to prevent one thread from getting undue priority to the resources of the multi-threaded processor.

Abstract: In a multi-threaded processor, thread priority variables are set up in memory. The actual assignment of thread priority is based on the expiration of a thread precedence counter. To further augment, the effectiveness of the thread precedence counters, starting counters are associated with each thread that serve as a multiplier for the value to be used in the thread precedence counter. The value in the starting counters are manipulated so as to prevent one thread from getting undue priority to the resources of the multi-threaded processor.

Abstract: In a multi-threaded processor, thread priority variables are set up in memory. The actual assignment of thread priority is based on the expiration of a thread precedence counter. To further augment, the effectiveness of the thread precedence counters, starting counters are associated with each thread that serve as a multiplier for the value to be used in the thread precedence counter. The value in the starting counters are manipulated so as to prevent one thread from getting undue priority to the resources of the multi-threaded processor.

Abstract: In a multi-threaded processor, thread priority variables are set up in memory. The actual assignment of thread priority is based on the expiration of a thread precedence counter. To further augment, the effectiveness of the thread precedence counters, starting counters are associated with each thread that serve as a multiplier for the value to be used in the thread precedence counter. The value in the starting counters are manipulated so as to prevent one thread from getting undue priority to the resources of the multi-threaded processor.

Abstract: In a multi-threaded processor, thread priority variables are set up in memory. The actual assignment of thread priority is based on the expiration of a thread precedence counter. To further augment, the effectiveness of the thread precedence counters, starting counters are associated with each thread that serve as a multiplier for the value to be used in the thread precedence counter. The value in the starting counters are manipulated so as to prevent one thread from getting undue priority to the resources of the multi-threaded processor.

Abstract: In a multi-threaded processor, thread priority variables are set up in memory. The actual assignment of thread priority is based on the expiration of a thread precedence counter. To further augment, the effectiveness of the thread precedence counters, starting counters are associated with each thread that serve as a multiplier for the value to be used in the thread precedence counter. The value in the starting counters are manipulated so as to prevent one thread from getting undue priority to the resources of the multi-threaded processor.

Abstract: In a multi-threaded processor, thread priority variables are set up in memory. According to an embodiment of the present invention, several conditions are monitored so as to determine an indication of instruction side starvation may be approaching. If such starvation is approaching, the starvation is resolved upon the expiration of a threshold counter or the like.

Abstract: According to one aspect of the invention, a microprocessor is provided that includes an execution core, a first replay mechanism and a second replay mechanism. The execution core performs data speculation in executing a first instruction. The first replay mechanism is used to replay the first instruction via a first replay path if an error of a first type is detected which indicates that the data speculation is erroneous. The second replay mechanism is used to replay the first instruction via a second replay path if an error of a second type is detected which indicates that the data speculation is erroneous.

Abstract: In a multi-threaded processor, thread priority variables are set up in memory. According to an embodiment of the present invention, several conditions are monitored so as to determine an indication of instruction side starvation may be approaching. If such starvation is approaching, the starvation is resolved upon the expiration of a threshold counter or the like.

Abstract: In a multi-threaded processor, thread priority variables are set up in memory. According to an embodiment of the present invention, several conditions are monitored so as to determine an indication of instruction side starvation may be approaching. If such starvation is approaching, the starvation is resolved upon the expiration of a threshold counter or the like.

Abstract: A request received from a requester to access a processor cache or register file or the like is buffered, by storing requestor identification, request type, address, and a status of the request. This buffered request may be forwarded to the cache if it has the highest priority among a number of buffered requests that also wish to access the cache. The priority is a function of at least the requestor identification, the requester type, and the status of the request. For buffered requests which include a read, the buffered request is deleted after, not before, receiving an indication that the requestor has received the data read from the cache.

Abstract: A processor including a first execution core section clocked to perform execution operations at a first clock frequency, and a second execution core section clocked to perform execution operations at a second clock frequency which is different than the first clock frequency. The second execution core section runs faster and includes a data cache and critical ALU functions, while the first execution core section includes latency-tolerant functions such as instruction fetch and decode units and non-critical ALU functions. The processor may further include an I/O ring which may be still slower than the first execution core section. Optionally, the first execution core section may include a third execution core section whose clock rate is between that of the first and second execution core sections. Clock multipliers/dividers may be used between the various sections to derive their clocks from a single source, such as the I/O clock.

Abstract: A processor including a first execution core section clocked to perform execution operations at a first clock frequency, and a second execution core section clocked to perform execution operations at a second clock frequency which is different than the first clock frequency. The second execution core section runs faster and includes a data cache and critical ALU functions, while the first execution core section includes latency-tolerant functions such as instruction fetch and decode units and non-critical ALU functions. The processor may further include an I/O ring which may be still slower than the first execution core section. Optionally, the first execution core section may include a third execution core section whose clock rate is between that of the first and second execution core sections. Clock multipliers/dividers may be used between the various sections to derive their clocks from a single source, such as the I/O clock.