Abstract: In an embodiment, a decode unit includes multiple decoders configured to decode different types of instructions. One or more of the decoders may be complex decoders, and the decode unit may disable the complex decoders if an instruction of the corresponding type is not being decoded. In an embodiment, the decode unit may disable the complex decoders by data-gating the instruction into the decoder. The decode unit may also include a control unit that is configured to detect instructions of the type decoded by the complex decoders, and to enable the complex decoders and redirect the fetching in response to the detection. The decode unit may also record an indication of the instruction (e.g. the program counter address (PC) of the instruction) to more rapidly detect the instruction and prevent a redirect in subsequent fetches.

Abstract: In an embodiment, a combining write buffer is configured to maintain one or more flush metrics to determine when to transmit write operations from buffer entries. The combining write buffer may be configured to dynamically modify the flush metrics in response to activity in the write buffer, modifying the conditions under which write operations are transmitted from the write buffer to the next lower level of memory. For example, in one implementation, the flush metrics may include categorizing write buffer entries as “collapsed.” A collapsed write buffer entry, and the collapsed write operations therein, may include at least one write operation that has overwritten data that was written by a previous write operation in the buffer entry. In another implementation, the combining write buffer may maintain the threshold of buffer fullness as a flush metric and may adjust it over time based on the actual buffer fullness.

Abstract: In one embodiment, a processor comprises a retire unit and a load/store unit coupled thereto. The retire unit is configured to retire a first store memory operation responsive to the first store memory operation having been processed at least to a pipeline stage at which exceptions are reported for the first store memory operation. The load/store unit comprises a queue having a first entry assigned to the first store memory operation. The load/store unit is configured to retain the first store memory operation in the first entry subsequent to retirement of the first store memory operation if the first store memory operation is not complete. The queue may have multiple entries, and more than one store may be retained in the queue after being retired by the retire unit.

Abstract: In one embodiment, a processor comprises a plurality of storage locations, a decode circuit, and a status/control register (SCR). Each storage location is addressable as a speculative register and is configured to store result data generated during execution of an instruction operation and a value representing an update for the SCR. The value includes at least a first encoding that represents an update to a plurality of bits in the SCR, and a first number of bits in the plurality of bits is greater than a second number of bits in the first encoding. The decode circuit is coupled to receive the first encoding from a first storage location responsive to retirement of a first instruction operation assigned to use the first storage location as a destination, and is configured to decode the first encoding and generate the plurality of bits. The decode circuit is configured to update the SCR.

Abstract: In one embodiment, a processor comprises a retire unit and a load/store unit coupled thereto. The retire unit is configured to retire a first store memory operation responsive to the first store memory operation having been processed at least to a pipeline stage at which exceptions are reported for the first store memory operation. The load/store unit comprises a queue having a first entry assigned to the first store memory operation. The load/store unit is configured to retain the first store memory operation in the first entry subsequent to retirement of the first store memory operation if the first store memory operation is not complete. The queue may have multiple entries, and more than one store may be retained in the queue after being retired by the retire unit.

Abstract: The invention relates to a crossbar switch controller including an input terminal configured to receive a set of service request signals from a set of virtual output queues each comprising a set of packets. The invention also includes a matrix circuit coupled to the input terminal and configured to represent the set of service request signals in the form of a matrix, wherein each service request signal is described by a row position M and a column position N. The invention further includes an output terminal configured to receive a portion of the set of packets during an epoch, an arbiter circuit configured to iteratively scan the matrix during the epoch and issue the set of grant signals to the virtual output queues to determine which service requests are granted, and an arbiter controller configured to initiate the arbiter circuit with an array of non-conflicting matrix elements.

Abstract: The invention relates to a crossbar switch controller including an input terminal configured to receive a set of service request signals from a set of virtual output queues each comprising a set of packets. The invention also includes a matrix circuit coupled to the input terminal and configured to represent the set of service request signals in the form of a matrix, wherein each service request signal is described by a row position M and a column position N. The invention further includes an output terminal configured to receive a portion of the set of packets during an epoch, an arbiter circuit configured to iteratively scan the matrix during the epoch and issue the set of grant signals to the virtual output queues to determine which service requests are granted, and an arbiter controller configured to initiate the arbiter circuit with an array of non-conflicting matrix elements.

Abstract: In one embodiment, a processor comprises a scheduler configured to issue a first instruction operation to be executed and an execution core coupled to the scheduler. Configured to execute the first instruction operation, the execution core comprises a plurality of replay sources configured to cause a replay of the first instruction operation responsive to detecting at least one of a plurality of replay cases. The scheduler is configured to inhibit issuance of the first instruction operation subsequent to the replay for a subset of the plurality of replay cases. The scheduler is coupled to receive an acknowledgement indication corresponding to each of the plurality of replay cases in the subset, and is configured to inhibit issuance of the first instruction operation until the acknowledgement indication is asserted that corresponds to an identified replay case of the subset.

Abstract: In one embodiment, a processor comprises a scheduler configured to issue a first instruction operation to be executed and an execution core coupled to the scheduler. Configured to execute the first instruction operation, the execution core comprises a plurality of replay sources configured to cause a replay of the first instruction operation responsive to detecting at least one of a plurality of replay cases. The scheduler is configured to inhibit issuance of the first instruction operation subsequent to the replay for a subset of the plurality of replay cases. The scheduler is coupled to receive an acknowledgement indication corresponding to each of the plurality of replay cases in the subset, and is configured to inhibit issuance of the first instruction operation until the acknowledge indication is asserted that corresponds to an identified replay case of the subset.

Abstract: A packet transmit queue control system including a first data structure, a second data structure, a packet controller, and a port transmit controller is disclosed. The first data structure can include a plurality of linked-list data structures and can store unicast type packet pointers. The second data structure can include a plurality of first-in first-out (FIFO) structures and can store multicast type packet pointers. The packet controller can receive a first sequence of unicast and/or multicast type packets. The port transmit controller can provide a second sequence of the unicast and/or multicast type packets. Further, each of the plurality of FIFO structures can correspond to an output port of the system.

Abstract: In one embodiment, a processor comprises a retire unit and a load/store unit coupled thereto. The retire unit is configured to retire a first store memory operation responsive to the first store memory operation having been processed at least to a pipeline stage at which exceptions are reported for the first store memory operation. The load/store unit comprises a queue having a first entry assigned to the first store memory operation. The load/store unit is configured to retain the first store memory operation in the first entry subsequent to retirement of the first store memory operation if the first store memory operation is not complete. The queue may have multiple entries, and more than one store may be retained in the queue after being retired by the retire unit.

Abstract: The invention relates to a crossbar switch controller including an input terminal configured to receive a set of service request signals from a set of virtual output queues each comprising a set of packets. The invention also includes a matrix circuit coupled to the input terminal and configured to represent the set of service request signals in the form of a matrix, wherein each service request signal is described by a row position M and a column position N. The invention further includes an output terminal configured to receive a portion of the set of packets during an epoch, an arbiter circuit configured to iteratively scan the matrix during the epoch and issue the set of grant signals to the virtual output queues to determine which service requests are granted, and an arbiter controller configured to initiate the arbiter circuit with an array of non-conflicting matrix elements.

Abstract: In one embodiment, a processor comprises a retire unit and a load/store unit coupled thereto. The retire unit is configured to retire a first store memory operation responsive to the first store memory operation having been processed at least to a pipeline stage at which exceptions are reported for the first store memory operation. The load/store unit comprises a queue having a first entry assigned to the first store memory operation. The load/store unit is configured to retain the first store memory operation in the first entry subsequent to retirement of the first store memory operation if the first store memory operation is not complete. The queue may have multiple entries, and more than one store may be retained in the queue after being retired by the retire unit.

Abstract: The invention relates to a crossbar switch controller including an input terminal configured to receive a set of service request signals from a set of virtual output queues each comprising a set of packets. It also includes a matrix circuit coupled to the input terminal and configured to represent the set of service request signals in the form of a matrix, wherein each service request signal is described by a row position M and a column position N. An output terminal is configured to receive a portion of the set of packets during an epoch, an arbiter circuit configured to iteratively scan the matrix during the epoch and issue the set of grant signals to the virtual output queues to determine which service requests are granted, and an arbiter controller configured to initiate the arbiter circuit with an array of non-conflicting matrix elements.

Abstract: In one embodiment, a renamer comprises a plurality of storage locations and compare circuitry. Each storage location is assigned to a respective renameable resource and is configured to store an identifier corresponding to a youngest instruction operation that writes the respective renameable resource. Coupled to receive an input representing one or more retiring instruction identifiers corresponding to instruction operations that are being retired, the compare circuitry is configured to detect a match between at least a first identifier in a first storage location and one of the retiring identifiers. An encoded form of the identifiers is logically divided into a plurality of fields, and the input comprises a first plurality of bit vectors. Each of the first plurality of bit vectors corresponds to a respective field and includes a bit position for each possible value of the respective field.

Abstract: In one embodiment, a processor comprises a retire unit and a load/store unit coupled thereto. The retire unit is configured to retire a first store memory operation responsive to the first store memory operation having been processed at least to a pipeline stage at which exceptions are reported for the first store memory operation. The load/store unit comprises a queue having a first entry assigned to the first store memory operation. The load/store unit is configured to retain the first store memory operation in the first entry subsequent to retirement of the first store memory operation if the first store memory operation is not complete. The queue may have multiple entries, and more than one store may be retained in the queue after being retired by the retire unit.

Abstract: In one embodiment, a processor comprises a scheduler configured to issue a first instruction operation to be executed and an execution core coupled to the scheduler. Configured to execute the first instruction operation, the execution core comprises a plurality of replay sources configured to cause a replay of the first instruction operation responsive to detecting at least one of a plurality of replay cases. The scheduler is configured to inhibit issuance of the first instruction operation subsequent to the replay for a subset of the plurality of replay cases. The scheduler is coupled to receive an acknowledgement indication corresponding to each of the plurality of replay cases in the subset, and is configured to inhibit issuance of the first instruction operation until the acknowledge indication is asserted that corresponds to an identified replay case of the subset.

Abstract: In one embodiment, a processor comprises a plurality of storage locations, a decode circuit, and a status/control register (SCR). Each storage location is addressable as a speculative register and is configured to store result data generated during execution of an instruction operation and a value representing an update for the SCR. The value includes at least a first encoding that represents an update to a plurality of bits in the SCR, and a first number of bits in the plurality of bits is greater than a second number of bits in the first encoding. The decode circuit is coupled to receive the first encoding from a first storage location responsive to retirement of a first instruction operation assigned to use the first storage location as a destination, and is configured to decode the first encoding and generate the plurality of bits. The decode circuit is configured to update the SCR.

Abstract: In one embodiment, a renamer comprises a plurality of storage locations and compare circuitry. Each storage location is assigned to a respective renameable resource and is configured to store an identifier corresponding to a youngest instruction operation that writes the respective renameable resource. Coupled to receive an input representing one or more retiring instruction identifiers corresponding to instruction operations that are being retired, the compare circuitry is configured to detect a match between at least a first identifier in a first storage location and one of the retiring identifiers. An encoded form of the identifiers is logically divided into a plurality of fields, and the input comprises a first plurality of bit vectors. Each of the first plurality of bit vectors corresponds to a respective field and includes a bit position for each possible value of the respective field.

Abstract: A packet transmit queue control system including a first data structure, a second data structure, a packet controller, and a port transmit controller is disclosed. The first data structure can include a plurality of linked-list data structures and can store unicast type packet pointers. The second data structure can include a plurality of first-in first-out (FIFO) structures and can store multicast type packet pointers. The packet controller can receive a first sequence of unicast and/or multicast type packets. The port transmit controller can provide a second sequence of the unicast and/or multicast type packets. Further, each of the plurality of FIFO structures can correspond to an output port of the system.