Vector LLVM checked in!


As advertised to some, I've checked in a BETA VERSION of my vector extensions to LLVM. It is checked in as a CVS branch off of the main line. You can get the branch by doing a normal llvm checkout and adding the argument -r vector_llvm. E.g., to check out from anonymous CVS, you would do this:

  • cvs -d login
  • Hit the return key when prompted for the password.
  • cvs -z3 -d co -r vector_llvm llvm

This will produce a fresh tree with the Vector LLVM stuff in it.

Vector LLVM consists of three main components:

1. Extensions to the VM core to support both fixed and variable vectors, and operations on them (the fixed vectors subsume the 'Packed Type' from regular LLVM).

2. A C API and supporting LLVM transformation for writing Vector LLVM at the C level using special functions that can be integrated with "normal" scalar code, compiled through llvm-gcc, and turned into Vector LLVM.

3. Very rudimentary backend support for turning fixed vectors into AltiVec and/or SSE via the C backend and the gcc SIMD intrinsics for C.

I've also written a backend for the Motorola RSVP coprocessor architecture that uses variable length vectors, but I can't check this in because it's proprietary.

#1 above is documented in llvm/src/docs/LangRef.html. I'm working on documentation for #2 and #3.

Feel free to check it out Vector LLVM and play with it. Comments/suggestions are welcome.


Robert L. Bocchino Jr.
Ph.D. Student, Computer Science
University of Illinois, Urbana-Champaign