A new WG21 paper is available. A copy is linked below, and the paper will also appear in the next normal WG21 mailing. If you are not a committee member, please use the comments section below or the std-proposals forum for public discussion.

Document number: N3759

Date: 2013-08-30

SIMD Vector Types

by Matthias Kretz

Excerpt:

The challenge remains in providing portable SIMD types and operations.

... 

C++ has no means to use SIMD operations directly. There are indirect uses through loop vectorization or optimized algorithms (that use extensions to C/C++ or assembler for their implementation).

All compiler vendors (that I worked with) add intrinsics support to their compiler products to make these operations accessible from C. These intrinsics are inherently not portable and most of the time very directly bound to a specific instruction. (Compilers are able to statically evaluate and optimize SIMD code written via intrinsics, though.) ...

... This is a pure library proposal. It does depend on implementation-specific language extensions, though (e.g. SIMD intrinsics/builtins). The proposal builds upon the experience from the Vc library [1, 2].