A decoder circuit may be configured to receive an instruction which includes a plurality of data bits and decode a first subset of the plurality of data bits. A transcode circuit may be configured to determine if the received instruction is to be modified and, in response to a determination that the received instruction is to be modified, modify a second subset of the plurality of data bits.

Apparatus and methods are disclosed for implementing block-based processors having custom function blocks, including field-programmable gate array (FPGA) implementations. In some examples of the disclosed technology, a dynamically configurable scheduler is configured to issue at least one block-based processor instruction. A custom function block is configured to receive input operands for the instruction and generate ready state data indicating completion of a computation performed for the instruction by the respective custom function block.

Instructions and logic provide vector load-op and/or store-op with stride functionality. Some embodiments, responsive to an instruction specifying: a set of loads, a second operation, destination register, operand register, memory address, and stride length; execution units read values in a mask register, wherein fields in the mask register correspond to stride-length multiples from the memory address to data elements in memory. A first mask value indicates the element has not been loaded from memory and a second value indicates that the element does not need to be, or has already been loaded. For each having the first value, the data element is loaded from memory into the corresponding destination register location, and the corresponding value in the mask register is changed to the second value. Then the second operation is performed using corresponding data in the destination and operand registers to generate results. The instruction may be restarted after faults.

In one embodiment, a processor includes an instruction decoder to receive a first instruction having a prefix and an opcode and to generate, by an instruction decoder of the processor, a second instruction executable based on a condition determined based on the prefix, and an execution unit to conditionally execute the second instruction based on the condition determined based on the prefix.

A processor including a memory controller for interfacing an external memory and a programmable functional unit (PFU). The PFU is programmed by a PFU program to modify operation of the memory controller, in which the PFU includes programmable logic elements and programmable interconnectors. For example, the PFU is programmed by the PFU program to add a function or otherwise to modify an existing function of the memory controller enhance its functionality during operation of the processor. In this manner, the functionality and/or operation of the memory controller is not fixed once the processor is manufactured, but instead the memory controller may be modified after manufacture to improve efficiency and/or enhance performance of the processor, such as when executing a corresponding process.

A processor can be used to ensure that program code can only be used for a designed purpose and not exploited by malware. Embodiments of an illustrative processor can comprise logic operable to execute a program instruction and to distinguish whether the program instruction is a legitimate branch instruction or a non-legitimate branch instruction.

This invention discloses a novel paradigm, method and apparatus for Matrix Computing which include a novel machine architecture with an embedded storage space for holding matrices and arrays for computing which can be accessed by its columns or by its rows or both concurrently. A large capacity multi length instruction set with instructions and methods to load, store and compute with these matrices and arrays are also disclosed; a method and apparatus to secure, share, lock and unlock this embedded space for matrices under the control of an Operating System or a Virtual Machine Monitor by a plurality of threads and processes are also disclosed. A novel method and apparatus to handle immediate operands used by Immediate Instructions are also disclosed. The structure of the instructions with some key fields and a method for determining instruction length easily are also disclosed.

A processor includes a decode unit to decode a three source floating point addition instruction indicating a first source operand having a first floating point data element, a second source operand having a second floating point data element, and a third source operand having a third floating point data element. An execution unit is coupled with the decode unit. The execution unit, in response to the instruction, stores a result in a destination operand indicated by the instruction. The result includes a result floating point data element that includes a first floating point rounded sum. The first floating point rounded sum represents an additive combination of a second floating point rounded sum and the third floating point data element. The second floating point rounded sum represents an additive combination of the first floating point data element and the second floating point data element.

An instruction to perform a comparison of a first value and a second value is executed. Based on a control of the instruction, a compare function to be performed is determined. The compare function is one of a plurality of compare functions configured for the instruction, and the compare function has a plurality of options for comparison. A compare option based on the first value and the second value is selected from the plurality of options defined for the compare function, and used to compare the first value and the second value. A result of the comparison is then placed in a select location, the result to be used in processing within a computing environment.

A microprocessor splits a fused multiply-accumulate operation of the form A*B+C into first and second multiply-accumulate sub-operations to be performed by a multiplier and an adder. The first sub-operation at least multiplies A and B, and conditionally also accumulates C to the partial products of A and B to generate an unrounded nonredundant sum. The unrounded nonredundant sum is stored in memory shared by the multiplier and adder for an indefinite time period, enabling the multiplier and adder to perform other operations unrelated to the multiply-accumulate operation. The second sub-operation conditionally accumulates C to the unrounded nonredundant sum if C is not already incorporated into the value, and then generates a final rounded result.