[cfe-dev] [request] Improve debugging of ffast-math optimizations

[Milian Wolff via cfe-dev]

On Sunday, April 24, 2016 10:51:38 AM CEST Hal Finkel via cfe-dev wrote:
> Hi!

<snip>

> For optimizations, like traditional reassociation (and reduction
> vectorization), we could use the backend "remark" feature to give users
> information on where these apply. On large codes, however, such information
> would be very noisy. For this to be useful we'd need to think about how to
> filter, I suspect we'd need to combine it with profiling information, so
> they we only generated the information on actually-executed (or even hot)
> paths.

Would it be much more noisy than reports on missed auto-vectorization 
opportunities? When I used those, I always piped the output to a file and 
browsed it in an editor to find the spots I knew are hot from separate 
profiler runs. Not perfect, but certainly doable and helpful and I would 
assume much easier to implement on the clang side.

Cheers
-- 
Milian Wolff
mail at milianw.de
http://milianw.de