[LLVMdev] What does promote elements do ?

[Anton Korobeynikov]

> It seems that it has been turned on by default in llc since LLVM 3.1 and it
> exposes a lot of BUG for ARM target.
>
> Not sure those are ARM backend bugs or promote elements bugs. However ARM
> BUGS are not release blockers, it is a significant regression versus LLVM
> 3.0.
I had the same feeling. Vector promotion was tested on x86 only, so
the bugs on ARM are expected (regardless whether they are bugs exposed
in ARM backend or in vector promotion itself).
Unfortunately, the author of the pass has no interest in touching ARM at all...

> Can this be disabled by default for ARM target ?
Right now we do not have even a flag to disable it... I'd suggest
start filling bugs for the problems, so, to make them known at least.

-- 
With best regards, Anton Korobeynikov
Faculty of Mathematics and Mechanics, Saint Petersburg State University