Abstract: A system for executing an accelerator call function includes a processor, a register context memory, an accelerator scheduler, multiple accelerator cores, and a stack memory. The processor executes a program task. The processor includes a register that stores task context information of the program task. The accelerator call function includes an accelerator operation. The processor forwards the accelerator operation to the accelerator scheduler. Concurrently, the processor stores the task context information in the register context memory. The accelerator scheduler identifies one of the accelerator cores and forwards the accelerator operation to the identified core. The identified core executes the accelerator operation, generates a return value, and stores the return value in the register context memory, which in turn provides the return value and the task context information to the processor.

Abstract: A method and information processing system provide trace compression for trace messages. In response to a branch of a conditional branch instruction having not been taken or having been taken, a flag of a history buffer is set or cleared. A trace address message is generated in response to a conditional indirect branch instruction being taken, wherein the trace address message includes address information indicating the destination address of the taken branch, and an index value indicating a corresponding flag of the history buffer. In response to a return from interrupt or return from exception instruction, a predicted return address is compared to an actual return address. A trace address message is generated in response to the predicted and actual return addresses not matching. A trace address message is not generated in response to the predicted and actual return addresses matching.

Abstract: In a processing system capable of single and multi-thread execution, a branch prediction unit can be configured to detect hard to predict branches and loop instructions. In a dual-threading (simultaneous multi-threading) configuration, one instruction queues (IQ) is used for each thread and instructions are alternately sent from each IQ to decode units. In single thread mode, the second IQ can be used to store the “not predicted path” of the hard-to-predict branch or the “fall-through” path of the loop. On mis-prediction, the mis-prediction penalty is reduced by getting the instructions from IQ instead of instruction cache.

Abstract: A method and information processing system provide trace compression for trace messages. In response to a branch of a conditional branch instruction having not been taken or having been taken, a flag of a history buffer is set or cleared. A trace address message is generated in response to a conditional indirect branch instruction being taken, wherein the trace address message includes address information indicating the destination address of the taken branch, and an index value indicating a corresponding flag of the history buffer. In response to a return from interrupt or return from exception instruction, a predicted return address is compared to an actual return address. A trace address message is generated in response to the predicted and actual return addresses not matching. A trace address message is not generated in response to the predicted and actual return addresses matching.

Abstract: In a processing system capable of single and multi-thread execution, a branch prediciton unit can be configured to detect hard to predict branches and loop instructions. In a dual-threading (simultaneous multi-threading) configuration, one instruction queues (IQ) is used for each thread and instructions are alternately sent from each IQ to decode units. In single thread mode, the second IQ can be used to store the “not predicted path” of the hard-to-predict branch or the “fall-through” path of the loop. On mis-prediction, the mis-prediction penalty is reduced by getting the instructions from IQ instead of instruction cache.

Abstract: A data processor includes a branch target buffer (BTB) having a plurality of BTB entries grouped in ways. The BTB entries in one of the ways include a short tag address and the BTB entries in another one of the ways include a full tag address.

Abstract: A data processor includes a branch target buffer (BTB) having a plurality of BTB entries grouped in ways. The BTB entries in one of the ways include a short tag address and the BTB entries in another one of the ways include a full tag address.