Apparatus and methods are disclosed for controlling execution of memory access instructions in a block-based processor architecture using a hardware structure that indicates a relative ordering of memory access instruction in an instruction block. In one example of the disclosed technology, a method of executing an instruction block having a plurality of memory load and/or memory store instructions includes selecting a next memory load or memory store instruction to execute based on dependencies encoded within the block, and on a store vector that stores data indicating which memory load and memory store instructions in the instruction block have executed. The store vector can be masked using a store mask. The store mask can be generated when decoding the instruction block, or copied from an instruction block header. Based on the encoded dependencies and the masked store vector, the next instruction can issue when its dependencies are available.

This invention is a streaming engine employed in a digital signal processor. A fixed data stream sequence is specified by a control register. The streaming engine fetches stream data ahead of use by a central processing unit and stores it in a stream buffer. Upon occurrence of a fault reading data from memory, the streaming engine identifies the data element triggering the fault preferably storing this address in a fault address register. The streaming engine defers signaling the fault to the central processing unit until this data element is used as an operand. If the data element is never used by the central processing unit, the streaming engine never signals the fault. The streaming engine preferably stores data identifying the fault in a fault source register. The fault address register and the fault source register are preferably extended control registers accessible only via a debugger.

In a method of operating a computer system, an instruction loop is executed by a processor in which each iteration of the instruction loop accesses a current data vector and an associated current vector predicate. The instruction loop is repeated when the current vector predicate indicates the current data vector contains at least one valid data element and the instruction loop is exited when the current vector predicate indicates the current data vector contains no valid data elements.

An instruction is executed to perform a query function. The executing includes obtaining information relating to a selected model of a processor. The information includes at least one model-dependent data attribute of the selected model of the processor. The information is placed in a selected location for use by at least one application in performing one or more functions.

Described herein is a graphics processing unit (GPU) comprising a first processing cluster to perform parallel processing operations, the parallel processing operations including a ray tracing operation and a matrix multiply operation; and a second processing cluster coupled to the first processing cluster, wherein the first processing cluster includes a floating-point unit to perform floating point operations, the floating-point unit is configured to process an instruction using a bfloat16 (BF16) format with a multiplier to multiply second and third source operands while an accumulator adds a first source operand with output from the multiplier.

An electronic device includes a cache, a processing cluster having one or more processors, and prefetch throttling circuitry that determines a congestion level of the processing cluster based on an extent to which the data retrieval requests sent from the processors to the cache are not satisfied by the cache. Congestion criteria require that the congestion level of the cluster is above a cluster congestion threshold. In accordance with a determination that the congestion level of the cluster satisfies the congestion criteria, the prefetch throttling circuit causes one of the processors to limit prefetch requests to the cache to prefetch requests of at least a threshold quality. In accordance with a determination that the congestion level of the cluster does not satisfy the congestion criteria, the prefetch throttling circuit forgoes causing the processors to limit prefetch requests to the cache to prefetch requests of at least the threshold quality.

Speculative execution using a page-level tracked load order queue includes: determining that a first load instruction targets a determined memory region; and in response to the first load instruction targeting the determined memory region, adding an entry to a page-level tracked load order queue instead of a load order queue, where the entry indicates a page address of a target of the first load instruction.

A method is provided that includes receiving, in a permute network, a plurality of data elements for a vector instruction from a streaming engine, and mapping, by the permute network, the plurality of data elements to vector locations for execution of the vector instruction by a vector functional unit in a vector data path of a processor.

A streaming engine employed in a digital data processor specifies a fixed read only data stream defined by plural nested loops. An address generator produces addresses of data elements. A steam head register stores data elements next to be supplied to functional units for use as operands. Stream metadata is stored in response to a stream store instruction. Stored stream metadata is restored to the stream engine in response to a stream restore instruction. An interrupt changes an open stream to a frozen state discarding stored stream data. A return from interrupt changes a frozen stream to an active state.

Accessing partial cachelines in a data cache including storing a first portion of a cacheline in a cache entry of the data cache; relaunching a load instruction targeting a second portion of the cacheline, wherein the second portion of the cacheline is not stored in the data cache; determining that the load instruction targets a portion of the cacheline not stored in the cache entry; storing the second portion of the cacheline in the data cache; and reading the second portion of the cacheline from the data cache according to the load instruction.