On Mon, Nov 1, 2010 at 9:27 AM, Paul Brook <p...@codesourcery.com> wrote: >> Hi All, >> >> Is it possible to define UNITS_PER_SIMD_WORD as a global variable and >> to set this varibale using a pragma (even once for a compilation) and >> that way to be able to compile one file with UNITS_PER_SIMD_WORD = 8 >> and another file with UNITS_PER_SIMD_WORD = 16? > > No. This is an internal value that is a property of the vector ISA you're > targeting. > > AFAIK there's only one supported target that supports variable length vectors > (ARM NEON), which allows selecting between doubleword and quadword vectors via > a target specific commandline option. Idealy you wouldn't need this at all, > but I don;t believe the vectorizer is capable of handling this.
x86 supports either 128bit (SSE) or 256bit (AVX) vectors. It works OK. -- H.J.
