There's been no release tagging or announcement yet, nor any communication about any delays, but in the past we have seen LLVM compiler infrastructure releases slip by a few days. There's been many Phoronix articles about LLVM 3.4 features, but for those that aren't up to date in their Phoronix readings, some of the major highlights include:
- The AMD R600 GPU LLVM back-end is no longer considered "experimental" and is enabled/built by default. This R600 GPU is mandated for RadeonSI Gallium3D usage, is optionally used by the R600g driver for a shader compiler, and is necessary for open-source Radeon OpenCL support. There's been a ton of improvements to the R600 LLVM back-end in LLVM 3.4.
- The Loop Vectorizer is now also used at -Os and -O2 optimization levels compared to just -O3 in LLVM 3.3.
- The new SLP Vectorizer has been enabled by default.
- Major work has been done on improving and extending the LLVM OCaml bindings.
- Support for the MIPS SIMD Architecture (MSA).
- Many improvements to the PowerPC back-end with faster code generation, support for new CPU features, bug-fixes, and much more.
- Experimental SPARC V9 back-end, SPARC JIT support, and many other SPARC architecture improvements.
Check out other Phoronix articles (e.g. this one) for more details on the LLVM 3.4 changes. On Phoronix I have also already run multiple LLVM Clang 3.4 compiler benchmarks as well. Stay tuned for forthcoming news about the official LLVM 3.4 release.