Abstract: A method and system for implementing vector prefetch with streaming access detection is contemplated in which an execution unit such as a vector execution unit, for example, executes a vector memory access instruction that references an associated vector of effective addresses. The vector of effective addresses includes a number of elements, each of which includes a memory pointer. The vector memory access instruction is executable to perform multiple independent memory access operations using at least some of the memory pointers of the vector of effective addresses. A prefetch unit, for example, may detect a memory access streaming pattern based upon the vector of effective addresses, and in response to detecting the memory access streaming pattern, the prefetch unit may calculate one or more prefetch memory addresses based upon the memory access streaming pattern. Lastly, the prefetch unit may prefetch the one or more prefetch memory addresses into a memory.

Abstract: Systems, apparatuses and methods for utilizing enhanced Macroscalar comparison operations which take an enhanced predicate operand that designates the element width and which elements are to be processed. The element width and the number of elements per vector are determined at run-time rather than being defined in the architectural definition of the instruction. This enables additional parallelism when processing smaller-sized data. The instruction performs the requested operation on the elements specified by the enhanced predicate, assuming an element-width also specified by the enhanced predicate, and returns the result as an enhanced predicate corresponding to the result of the comparison.

Abstract: Systems, apparatuses and methods for utilizing enhanced macroscalar predicate operations which take enhanced predicate operands that designate the element width and which elements are to be processed. The element width and the number of elements per vector are determined at run-time rather than being defined in the architectural definition of the instruction. This enables additional parallelism when processing smaller-sized data. The instruction performs the requested operation on the elements specified by the enhanced control predicate, assuming an element-width also specified by the enhanced control predicate, and returns the result as an enhanced predicate of the same element width.

Abstract: Systems, apparatuses and methods for utilizing enhanced vector true/false instructions. The enhanced vector true/false instructions generate enhanced predicates to correspond to the request element width and/or vector size. A vector true instruction generates an enhanced predicate where all elements supported by the processing unit are active. A vector false instruction generates an enhanced predicate where all elements supported by the processing unit are inactive. The enhanced predicate specifies the requested element width in addition to designating the element selectors.

Abstract: Systems, apparatuses and methods for utilizing enhanced predicate registers which specify the element width and which elements are to be processed. The predicate size is dynamic, depending on the contents of the enhanced predicate register used for an instruction rather than being a static quality of a specific instruction. Specifying the element size in the enhanced predicate registers results in fewer instructions in an instruction set.

Abstract: Systems, apparatuses and methods for utilizing enhanced Macroscalar vector operations which take an enhanced predicate operand that designates the element width and which elements are to be processed. The element width and the number of elements per vector are determined at run-time rather than being defined in the architectural definition of the instruction. This enables additional parallelism when processing smaller-sized data. The instruction performs the requested operation on the elements specified by the enhanced predicate, assuming an element-width also specified by the enhanced predicate, and returns the result as a vector of elements of the same element width.

Abstract: The described embodiments include a processor that executes a vector instruction. The processor starts by receiving a start value and an increment value, and optionally receiving a predicate vector with N elements as inputs. The processor then executes the vector instruction. Executing the vector instruction causes the processor to generate a result vector. When generating the result vector, if the predicate vector is received, for each element in the result vector for which a corresponding element of the predicate vector is active, otherwise, for each element in the result vector, the processor sets the element in the result vector equal to the start value plus a product of the increment value multiplied by a specified number of elements to the left of the element in the result vector.

Abstract: The described embodiments provide a processor for generating a result vector with incremented or decremented values from an input vector. During operation, the processor receives an input vector and a control vector. The processor then copies a value contained in a selected element of the input vector. The processor next generates the result vector, which involves writing an incremented or decremented value to the result vector, depending on the value of the control vector and the embodiment. In addition, a predicate vector can be used to control the values that are written to the result vector.

Abstract: Embodiments of a method for performing parallel operations in a computer system when one or more conditional dependencies may be present, where a given conditional dependency includes a dependency associated with at least two data elements based on a pair of conditions. During operation, a processor receives instructions for generating one or more predicate values based on actual dependencies, where a given predicate value indicates data elements that may be safely evaluated in parallel, and where the given actual dependency occurs when the pair of conditions matches one or more criteria. Then, the processor executes the instructions for generating the one or more predicate values.

Abstract: The described embodiments provide a processor that executes vector instructions. In the described embodiments, the processor initializes an architectural fault-status register (FSR) and a shadow copy of the architectural FSR by setting each of N bit positions in the architectural FSR and the shadow copy of the architectural FSR to a first predetermined value. The processor then executes a first first-faulting or non-faulting (FF/NF) vector instruction. While executing the first vector instruction, the processor also executes one or more subsequent FF/NF instructions. In these embodiments, when executing the first vector instruction and the subsequent vector instructions, the processor updates one or more bit positions in the shadow copy of the architectural FSR to a second predetermined value upon encountering a fault condition.

Abstract: A mechanism for executing speculative predicated instructions may include execution of initiating execution of a vector instruction when one or more operands upon which the vector instruction depends are available for use, even if a predicate vector that the vector instruction also depends is not available. If the predicate vector was not available, the results of the execution of the vector instruction may be temporarily held until the predicate vector becomes available, at which time, a destination vector may be updated with the results.

Abstract: The described embodiments include a processor that executes a vector instruction. The processor starts by receiving an input vector and optionally receiving a predicate vector as inputs. The processor then executes the vector instruction, which causes the processor to determine a key element position in the input vector and generate a result vector. When generating the result vector, if the predicate vector is received, for each element in the result vector for which a corresponding element of the predicate vector is active, otherwise, for each element of the result vector, the processor sets each element of the result vector to the right of the key element to a first predetermined value and sets each element of the result vector at or to the left of the key element to a second predetermined value. The processor then sets one or more processor status flags based on the values in the result vector.

Abstract: A method of predicting a backward conditional branch instruction used in a vector partitioning loop includes detecting the first conditional branch instruction that occurs after consumption of a dependency index vector by a predicate generating instruction. The dependency index vector includes information indicative of a number of iterations of the vector partitioning loop, and the conditional branch instruction may branch backwards when taken. The conditional branch instruction may then be predicted to be taken a number of times that is determined by the dependency index vector.

Abstract: Systems and methods for the vectorization of software applications are described. In some embodiments, source code dependencies can be expressed in ways that can extend a compiler's ability to vectorize otherwise scalar functions. For example, when compiling a called function, a compiler may identify dependencies of the called function on variables other than parameters passed to the called function. The compiler may record these dependencies, e.g., in a dependency file. Later, when compiling a calling function that calls the called function, the same (or another) compiler may reference the previously-identified dependencies and use them to determine whether and how to vectorize the calling function. In particular, these techniques may facilitate the vectorization of non-leaf loops. Because non-leaf loops are relatively common, the techniques described herein can increase the amount of vectorization that can be applied to many applications.

Abstract: A method for suppressing branch misprediction behavior is contemplated in which a branch-optional instruction that would cause the flow of control to branch around instructions in response to a determination that a predicate vector is null is predicted not taken. However, in response to detecting that the prediction is incorrect, misprediction behavior is inhibited.

Abstract: A method and system for implementing vector prefetch with streaming access detection is contemplated in which an execution unit such as a vector execution unit, for example, executes a vector memory access instruction that references an associated vector of effective addresses. The vector of effective addresses includes a number of elements, each of which includes a memory pointer. The vector memory access instruction is executable to perform multiple independent memory access operations using at least some of the memory pointers of the vector of effective addresses. A prefetch unit, for example, may detect a memory access streaming pattern based upon the vector of effective addresses, and in response to detecting the memory access streaming pattern, the prefetch unit may calculate one or more prefetch memory addresses based upon the memory access streaming pattern. Lastly, the prefetch unit may prefetch the one or more prefetch memory addresses into a memory.

Abstract: Embodiments of a system and a method in which a processor may execute instructions that cause the processor to receive an input vector and a control vector are disclosed. The executed instructions may also cause the processor to perform a negation operation dependent upon the input vector and the control vector.

Abstract: A macroscalar processor architecture is described herein. In one embodiment, a processor receives instructions of a program loop having a vector block and a sequence block intended to be executed after the vector block, where the processor includes multiple slices and each of the slices is capable of executing an instruction of an iteration of the program loop substantially in parallel. For each iteration of the program loop, the processor executes an instruction of the sequence block using one of the slices while executing instructions of the vector block using a remainder of the slices substantially in parallel. Other methods and apparatuses are also described.

Abstract: The described embodiments include a processor that handles faults during execution of a vector instruction. The processor starts by receiving a vector instruction that uses at least one vector of values that includes N elements as an input. In addition, the processor optionally receives a predicate vector that includes N elements. The processor then executes the vector instruction. In the described embodiments, when executing the vector instruction, if the predicate vector is received, for each element in the vector of values for which a corresponding element in the predicate vector is active, otherwise, for each element in the vector of values, the processor performs an operation for the vector instruction for the element in the vector of values. While performing the operation, the processor conditionally masks faults encountered (i.e., faults caused by an illegal operation).

Abstract: Embodiments of a system and a method in which a processor may execute instructions that cause the processor to receive an input vector and a control vector are disclosed. The executed instructions may also cause the processor to perform a Boolean operation on another input vector dependent upon the input vector and the control vector.