SIMD VARIABLE SHIFT AND ROTATE USING CONTROL MANIPULATION

摘要

Vector single instruction multiple data (SIMD) shift and rotate instructions are provided specifying: a destination vector register comprising fields to store vector elements, a first vector register, a vector element size, and a second vector register. Vector data fields of a first element size are duplicated. Duplicate vector data fields are stored as corresponding data fields of twice the first element size. Control logic receives an element size for performing a SIMD shift or rotation operation. Through selectors corresponding to a vector element, portions are selected from the duplicated data fields, the selectors corresponding to any particular vector element select all portions similarly from the duplicated data fields for that particular vector element responsive to the first element size, but selectors corresponding to any particular vector element select at least two portions from the duplicated data fields differently for that particular vector element responsive to a second element size.

主权项

1. A machine implemented method comprising:
duplicating a plurality of vector data fields of a first element size; storing the duplicate vector data fields as corresponding duplicated data fields of twice the first element size; receiving in a control logic an element size for performing a SIMD rotation on vector elements; and selecting, through a plurality of selectors corresponding to a particular vector element, portions from the duplicated data fields, the plurality of selectors corresponding to any particular vector element selecting all portions similarly from the duplicated data fields for that particular vector element responsive to the control logic receiving the first element size for performing the SIMD rotation on vector elements, but the plurality of selectors corresponding to any particular vector element selecting at least two portions from the duplicated data fields differently for that particular vector element responsive to the control logic receiving a second element size for performing the SIMD rotation on vector elements.