Abstract: A method, computer program product, and information handling system for generating loop code to execute on Single-Instruction Multiple-Datapath (SIMD) architectures, where the loop operates on datatypes having different lengths, is disclosed. Further, a preferred embodiment of the present invention includes a novel technique to efficiently realign or shift arbitrary streams to an arbitrary offset, regardless whether the alignments or offsets are known at the compile time or not. This technique enables the application of advanced alignment optimizations to runtime alignment. Length conversion operations, for packing and unpacking data values, are included in the alignment handling framework. These operations are formally defined in terms of standard SIMD instructions that are readily available on various SIMD platforms. This allows sequential loop code operating on datatypes of disparate length to be transformed (“simdized”) into optimized SIMD code through a fully automated process.

Abstract: A method, computer program product, and information handling system for generating mixed-mode operations in the compilation of program code for processors having vector or SIMD processing units is disclosed. In a preferred embodiment of the present invention, program instructions making up the body of a loop are abstracted into virtual vector instructions. These virtual vector instructions are treated, for initial code optimization purposes, as vector instructions (i.e., instructions written for the vector unit). The virtual vector instructions are eventually expanded into native code for the target processor, at which time a determination is made for each virtual vector instruction as to whether to expand the virtual vector instruction into native vector instructions, into native scalar instructions, into calls to pre-defined library functions, or into a combination of these.