Techniques for performing instruction fetch operations are provided. The techniques include determining instruction addresses for a primary branch prediction path; requesting that a level 0 translation lookaside buffer (“TLB”) caches address translations for the primary branch prediction path; determining either or both of alternate control flow path instruction addresses and lookahead control flow path instruction addresses; and requesting that either the level 0 TLB or an alternative level TLB caches address translations for either or both of the alternate control flow path instruction addresses and the lookahead control flow path instruction addresses.

Representative apparatus, method, and system embodiments are disclosed for a self-scheduling processor which also provides additional functionality. Representative embodiments include a self-scheduling processor, comprising: a processor core adapted to execute instructions; and a core control circuit adapted to automatically schedule an instruction for execution by the processor core in response to a received work descriptor data packet. In a representative embodiment, the processor core is further adapted to execute a non-cached load instruction to designate a general purpose register rather than a data cache for storage of data received from a memory circuit. The core control circuit is also adapted to schedule a fiber create instruction for execution by the processor core, and to generate one or more work descriptor data packets to another circuit for execution of corresponding execution threads. Event processing, data path management, system calls, memory requests, and other new instructions are also disclosed.

Systems and methods are disclosed for checker cores for fault tolerant processing. For example, an integrated circuit (e.g., a processor) for executing instructions includes a processor core configured to execute instructions of an instruction set; an outer memory system configured to store instructions and data; and a checker core configured to receive committed instruction packets from the processor core and check the committed instruction packets for errors, wherein the checker core is configured to utilize a memory pathway of the processor core to access the outer memory system by receiving instructions and data read from the outer memory system as portions of committed instruction packets from the processor core. For example, data flow from the processor core to the checker core may be limited to committed instruction packets received via dedicated a wire bundle.

A cache system may include a cache to store a plurality of cache lines in a write-back mode; dirty cache line counter circuitry to store a count of dirty cache lines in the cache, increment the count when a new dirty cache line is added to the cache, and decrement the count when an old dirty cache line is written-back from the cache; dirty cache line write-back tracking circuitry to store an ordering of the dirty cache lines in a write-back order; mapping circuitry to map the dirty lines into the ordering; and controller circuity to use the mapping circuity to identify an evicted dirty cache line in the ordering and remove the evicted dirty cache line from the ordering.

A streaming engine employed in a digital data processor may specify a fixed read-only data stream defined by plural nested loops. An address generator produces address of data elements for the nested loops. A steam head register stores data elements next to be supplied to functional units for use as operands. A stream template register independently specifies a linear address or a circular address mode for each of the nested loops.

A streaming engine employed in a digital signal processor specifies a fixed read only data stream. Once fetched the data stream is stored in two head registers for presentation to functional units in the fixed order. Data use by the functional unit is preferably controlled using the input operand fields of the corresponding instruction. A first read only operand coding supplies data from the first head register. A first read/advance operand coding supplies data from the first head register and also advances the stream to the next sequential data elements. Corresponding second read only operand coding and second read/advance operand coding operate similarly with the second head register. A third read only operand coding supplies double width data from both head registers.

A streaming engine employed in a digital signal processor specified a fixed data stream. Once started the data stream is read only and cannot be written. Once fetched the data stream is stored in a first-in-first-out buffer for presentation to functional units in the fixed order. Data use by the functional unit is controlled using the input operand fields of the corresponding instruction. A read only operand coding supplies the data an input of the functional unit. A read/advance operand coding supplies the data and also advances the stream to the next sequential data elements. The read only operand coding permits reuse of data without requiring a register of the register file for temporary storage.

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.

Methods, apparatus, systems and articles of manufacture are disclosed facilitate read-modify-write support in a coherent victim cache with parallel data paths. An example apparatus includes a random-access memory configured to be coupled to a central processing unit via a first interface and a second interface, the random-access memory configured to obtain a read request indicating a first address to read via a snoop interface, an address encoder coupled to the random-access memory, the address encoder to, when the random-access memory indicates a hit of the read request, generate a second address corresponding to a victim cache based on the first address, and a multiplexer coupled to the victim cache to transmit a response including data obtained from the second address of the victim cache.

This invention involves a cache system in a digital data processing apparatus including: a central processing unit core; a level one instruction cache; and a level two cache. The cache lines in the second level cache are twice the size of the cache lines in the first level instruction cache. The central processing unit core requests additional program instructions when needed via a request address. Upon a miss in the level one instruction cache that causes a hit in the upper half of a level two cache line, the level two cache supplies the upper half level cache line to the level one instruction cache. On a following level two cache memory cycle, the level two cache supplies the lower half of the cache line to the level one instruction cache. This cache technique thus prefetches the lower half level two cache line employing fewer resources than an ordinary prefetch.