Abstract: A system and a method to cascade execution of instructions in a load-store unit (LSU) of a central processing unit (CPU) to reduce latency associated with the instructions. First data stored in a cache is read by the LSU in response a first memory load instruction of two immediately consecutive memory load instructions. Alignment, sign extension and/or endian operations are performed on the first data read from the cache in response to the first memory load instruction, and, in parallel, a memory-load address-forwarded result is selected based on a corrected alignment of the first data read in response to the first memory load instruction to provide a next address for a second of the two immediately consecutive memory load instructions. Second data stored in the cache is read by the LSU in response to the second memory load instruction based on the selected memory-load address-forwarded result.

Abstract: A system and a method are disclosed to process instructions in an execution unit (EU) that includes an operand cache (OC). The OC stores a copy of at least one frequently used operand stored in a physical register file (PRF). The EU may process instructions using operands obtained from the PRF or from the OC. In the first mode, an OC renaming unit (OC-REN) indicates to the EU to process instructions using operands obtained from the OC if processing the instructions using operands obtained from the OC uses less power than using operands obtained from the PRF. In the second mode, the OC-REN indicates to the EU to process the instructions using operands obtained from the PRF if processing the instructions using operands obtained from the PRF uses less power than using operands obtained from the OC.

Abstract: A system and a method are disclosed to process instructions in an execution unit (EU) that includes an operand cache (OC). The OC stores a copy of at least one frequently used operand stored in a physical register file (PRF). The EU may process instructions using operands obtained from the PRF or from the OC. In the first mode, an OC renaming unit (OC-REN) indicates to the EU to process instructions using operands obtained from the OC if processing the instructions using operands obtained from the OC uses less power than using operands obtained from the PRF. In the second mode, the OC-REN indicates to the EU to process the instructions using operands obtained from the PRF if processing the instructions using operands obtained from the PRF uses less power than using operands obtained from the OC.

Abstract: A system and a method to cascade execution of instructions in a load-store unit (LSU) of a central processing unit (CPU) to reduce latency associated with the instructions. First data stored in a cache is read by the LSU in response a first memory load instruction of two immediately consecutive memory load instructions. Alignment, sign extension and/or endian operations are performed on the first data read from the cache in response to the first memory load instruction, and, in parallel, a memory-load address-forwarded result is selected based on a corrected alignment of the first data read in response to the first memory load instruction to provide a next address for a second of the two immediately consecutive memory load instructions. Second data stored in the cache is read by the LSU in response to the second memory load instruction based on the selected memory-load address-forwarded result.

Abstract: A system and a method to cascade execution of instructions in a load-store unit (LSU) of a central processing unit (CPU) to reduce latency associated with the instructions. First data stored in a cache is read by the LSU in response a first memory load instruction of two immediately consecutive memory load instructions. Alignment, sign extension and/or endian operations are performed on the first data read from the cache in response to the first memory load instruction, and, in parallel, a memory-load address-forwarded result is selected based on a corrected alignment of the first data read in response to the first memory load instruction to provide a next address for a second of the two immediately consecutive memory load instructions. Second data stored in the cache is read by the LSU in response to the second memory load instruction based on the selected memory-load address-forwarded result.

Abstract: According to one general aspect, an apparatus may include a branch prediction unit, a fetch unit, and a pre-fetch circuit or unit. The branch prediction unit may be configured to output a predicted instruction. The fetch unit may be configured to fetch a next instruction from a cache memory. The pre-fetcher circuit may be configured to pre-fetch a previously predicted instruction into the cache memory based upon a relationship between the predicted instruction and the next instruction.

Abstract: According to one general aspect, a load unit may include a load circuit configured to load at least one piece of data from a memory. The load unit may include an alignment circuit configured to align the data to generate an aligned data. The load unit may also include a mathematical operation execution circuit configured to generate a resultant of a predetermined mathematical operation with the at least one piece of data as an operand. Wherein the load unit is configured to, if an active instruction is associated with the predetermined mathematical operation, bypass the alignment circuit and input the piece of data directly to the mathematical operation execution circuit.

Abstract: According to one general aspect, a load unit may include a load circuit configured to load at least one piece of data from a memory. The load unit may include an alignment circuit configured to align the data to generate an aligned data. The load unit may also include a mathematical operation execution circuit configured to generate a resultant of a predetermined mathematical operation with the at least one piece of data as an operand. Wherein the load unit is configured to, if an active instruction is associated with the predetermined mathematical operation, bypass the alignment circuit and input the piece of data directly to the mathematical operation execution circuit.

Abstract: A system and a method to cascade execution of instructions in a load-store unit (LSU) of a central processing unit (CPU) to reduce latency associated with the instructions. First data stored in a cache is read by the LSU in response a first memory load instruction of two immediately consecutive memory load instructions. Alignment, sign extension and/or endian operations are performed on the first data read from the cache in response to the first memory load instruction, and, in parallel, a memory-load address-forwarded result is selected based on a corrected alignment of the first data read in response to the first memory load instruction to provide a next address for a second of the two immediately consecutive memory load instructions. Second data stored in the cache is read by the LSU in response to the second memory load instruction based on the selected memory-load address-forwarded result.

Abstract: According to one general aspect, an apparatus mat include a branch prediction unit, a fetch unit, and a pre-fetch circuit or unit. The branch prediction unit may be configured to output a predicted instruction. The fetch unit may be configured to fetch a next instruction from a cache memory. The pre-fetcher circuit may be configured to pre- fetch a previously predicted instruction into the cache memory based upon a relationship between the predicted instruction and the next instruction.

Abstract: A system includes a processor including at least a first core and a local interrupt controller associated with the first core. The first core is operable to store its architectural state prior to entering a first core sleep state, and the processor is operable to receive and implement a request for entering a system sleep state in which the first core is in the first core sleep state and the local interrupt controller is powered down and exit the system sleep state by restoring the local interrupt controller and restoring the saved architectural state of the first core.

Abstract: Methods, integrated circuit devices, and fabrication processes relating to power management transitions of a compute unit comprising a cache are presented. One method includes, responsive to an indication that the compute unit is attempting to enter a low power state, detecting at least one line of the cache differing from the corresponding line in memory, writing differing data from the at least one differing line to the memory, flushing at least one remaining differing line of the cache, and permitting the compute unit to enter the low power state, wherein the detecting and the writing are performed at a first frequency prior to the indication and at a second frequency subsequent the indication, and the second frequency is higher than the first frequency.

Abstract: According to one general aspect, an apparatus may include an instruction fetch unit, an execution unit, and a cache resynchronization predictor, as described above. The instruction fetch unit may be configured to issue a first memory read operation to a memory address, and a first memory write operation to the memory address, wherein the first memory read operation is stored at an instruction address. The execution unit may be configured to execute the first memory read operation, wherein the execution of the first memory read operation causes a resynchronization exception. The cache resynchronization predictor may be configured to associate the instruction address with a resynchronization exception, and determine if a memory read operation stored at the instruction address comprises a resynchronization predicted store.

Abstract: According to one general aspect, a method may include requesting, from a second tier of a cache memory system, a first instruction stored at a first memory address. The method may also include requesting, from a second tier of a branch target buffer system, a branch record associated with the first memory address. The method may also include receiving the branch record before receiving the first instruction. The method may also include pre-fetching, in response to receiving the branch record and before receiving the first instruction, a non-sequential instruction stored at a non-sequential memory address.

Abstract: According to one general aspect, an apparatus may include an instruction fetch unit, an execution unit, and a cache resynchronization predictor, as described above. The instruction fetch unit may be configured to issue a first memory read operation to a memory address, and a first memory write operation to the memory address, wherein the first memory read operation is stored at an instruction address. The execution unit may be configured to execute the first memory read operation, wherein the execution of the first memory read operation causes a resynchronization exception. The cache resynchronization predictor may be configured to associate the instruction address with a resynchronization exception, and determine if a memory read operation stored at the instruction address comprises a resynchronization predicted store.

Abstract: Methods, integrated circuit devices, and fabrication processes relating to power management transitions of a compute unit comprising a cache are presented. One method includes, responsive to an indication that the compute unit is attempting to enter a low power state, detecting at least one line of the cache differing from the corresponding line in memory, writing differing data from the at least one differing line to the memory, flushing at least one remaining differing line of the cache, and permitting the compute unit to enter the low power state, wherein the detecting and the writing are performed at a first frequency prior to the indication and at a second frequency subsequent the indication, and the second frequency is higher than the first frequency.

Abstract: A system includes a processor including at least a first core and a local interrupt controller associated with the first core. The first core is operable to store its architectural state prior to entering a first core sleep state, and the processor is operable to receive and implement a request for entering a system sleep state in which the first core is in the first core sleep state and the local interrupt controller is powered down and exit the system sleep state by restoring the local interrupt controller and restoring the saved architectural state of the first core.