A method may include determining, with a queue availability module, that an entry is available in a queue, asserting a bit in a register based on determining that an entry is available in the queue, determining, with a processor, that the bit is asserted, and processing, with the processor, the entry in the queue based on determining that the bit is asserted. The method may further include storing the register in a tightly coupled memory associated with the processor. The method may further include storing the queue in the tightly coupled memory. The method may further include determining, with the queue availability module, that an entry is available in a second queue, and asserting a second bit in the register based on determining that an entry is available in the second queue. The method may further include finding the first bit in the register using a find first instruction.

Detecting execution hazards in offloaded operations is disclosed. A second offload operation is compared to a first offload operation that precedes the second offload operation. It is determined whether the second offload operation creates an execution hazard on an offload target device based on the comparison of the second offload operation to the first offload operation. If the execution hazard is detected, an error handling operation may be performed. In some examples, the offload operations are processing-in-memory operations.

Systems and methods for reusing load instructions by a processor without accessing a data cache include a load store execution unit (LSU) of the processor, the LSU being configured to determine if a prior execution of a first load instruction loaded data from a first cache line of the data cache and determine if a current execution of the second load instruction will load the data from the first cache line of the data cache. Further, the LSU also determines if a reuse of the data from the prior execution of the first load instruction for the current execution of the second load instruction will lead to functional errors. If there are no functional errors, the data from the prior execution of the first load instruction is reused for the current execution of the second load instruction, without accessing the data cache for the current execution of the second load instruction.

Restricted instructions are prohibited from execution within a transaction. There are classes of instructions that are restricted regardless of type of transaction: constrained or nonconstrained. There are instructions only restricted in constrained transactions, and there are instructions that are selectively restricted for given transactions based on controls specified on instructions used to initiate the transactions.

A processor identifies matches between a load operation and a plurality of more store operations based on an address vector that represents a combination of addresses targeted by the store operations. The address vector is used to identify a potential match between an address targeted by the load operation and at least one of the addresses targeted by the plurality of store operations. This allows the processor to quickly identify when there are no potential matches between the load operation and any of the plurality of store operations, thereby reducing overhead at the processor and improving overall processing efficiency.

An apparatus and method are described for performing SIMD reduction operations. For example, one embodiment of a processor comprises: a value vector register containing a plurality of data element values to be reduced; an index vector register to store a plurality of index values indicating which values in the value vector register are associated with one another; single instruction multiple data (SIMD) reduction logic to perform reduction operations on the data element values within the value vector register by combining data element values from the value vector register which are associated with one another as indicated by the index values in the index vector register; and an accumulation vector register to store results of the reduction operations generated by the SIMD reduction logic.

Apparatus and methods are disclosed for implementing block-based processors including field programmable gate-array implementations. In one example of the disclosed technology, a block-based processor includes an instruction decoder configured to generate decoded ready dependencies for a transactional block of instructions, where each of the instructions is associated with a different instruction identifier encoded in the transactional block. The processor further includes an instruction scheduler configured to issue an instruction from a set of instructions of the transactional block of instructions. The instruction is issued based on determining that decoded ready state dependencies for an instruction are satisfied. The determining includes accessing storage with the decoded ready dependencies indexed with a respective instruction identifier that is encoded in the transactional block of instructions.

A microprocessor and a method for issuing a load/store instruction is introduced. The microprocessor includes a decode/issue unit, a load/store queue, a scoreboard, and a load/store unit. The scoreboard includes a plurality of scoreboard entries, in which each scoreboard entry includes an unknown bit value and a count value, wherein the unknown bit value or the count value is set when instructions are issued. The decode/issue unit checks for WAR, WAW, and RAW data dependencies from the scoreboard and dispatches load/store instructions to the load/store queue with the recorded scoreboard values. The load/store queue is configured to resolve the data dependencies and dispatch the load/store instructions to the load/store unit for execution.

A method for operation of a processor core is provided. A rejected first load instruction is received that has been rejected due to a false load-hit-store detection against a first store instruction. A warning label is generated on a basis of the false load-hit-store detection. The warning label is added to the received first load instruction to create a labeled first load instruction. The labeled first load instruction is issued such that the warning label causes the labeled first load instruction to bypass the first store instruction in the store reorder queue and thereby avoid another false load-hit-store detection against the first store instruction. A computer system and a processor core configured to operate according to the method are also disclosed herein.

An on-chip cache is described which receives memory requests and in the event of a cache miss, the cache generates memory requests to a lower level in the memory hierarchy (e.g. to a lower level cache or an external memory). Data returned to the on-chip cache in response to the generated memory requests may be received out-of-order. An instruction scheduler in the on-chip cache stores pending received memory requests and effects the re-ordering by selecting a sequence of pending memory requests for execution such that pending requests relating to an identical cache line are executed in age order and pending requests relating to different cache lines are executed in an order dependent upon when data relating to the different cache lines is returned. The memory requests which are received may be received from another, lower level on-chip cache or from registers.