An Abstraction Layer for SIMD Extensions

This paper presents an abstraction layer for short vector SIMD ISA extensions like Intel’s SSE, AMD’s 3DNow!, Motorola’s AltiVec, and IBM’s Double Hummer. It provides unified access to short vector instructions via intermediate level building blocks. These primitives are C macros that allow, for instance, portable and highly efficient implementations of discrete linear transforms like FFTs and DCTs. The newly developed API is built on top of recently introduced C language extensions that allow to access short vector SIMD hardware from within C programs by means of data types and intrinsic or built-in functions. Empirical evidence of the success of the portable SIMD API is provided by means of program runs of short vector versions of Spiral and Fftw, resulting in the fastest FFT implementations to date.