Generating predicate values based on conditional data dependency in vector processors

摘要

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.

主权项

1. A method for performing parallel operations in a computer system when one or more actual loop-carried dependencies may be present, comprising:
at runtime, receiving instructions for generating predicate values based on actual loop-carried dependencies, the instructions comprising instructions that:
generate a sequence of values based on evaluating a condition for elements of an input vector, each element of the input vector representing a corresponding loop iteration;determine positions where adjacent elements in the sequence of values meet one or more criteria, the criteria indicating an actual loop-carried dependency; andgenerate the predicate values based on the determination; and executing the instructions for generating the predicate values.