halide/Halide — pull request #480 by DanielHeck (2014-09-24 15:10:21+00:00)
Title: Defer lowering of log, exp, pow until codegen

- Change halide_log, halide_exp to work with vectors since they are now lowered
after vectorization. Move handling of constant arguments to the simplifier.

- Change floor, ceil, round to work with vectors (mostly because floor is used inside halide_exp)