[PATCH] D74436: Change clang option -ffp-model=precise to select ffp-contract=on

Fri Feb 14 15:07:08 PST 2020

andrew.w.kaylor added a comment.

In D74436#1875315 <https://reviews.llvm.org/D74436#1875315>, @nemanjai wrote:

> > You're right, -O0 shouldn't generate FMA. I'm preparing to revert this now -- just verifying the build.
>
> Perhaps this should be
>  `off` with no optimization
>  `on` with `-O1/-O2/-O3/-Os/-Oz`
>  `fast` with fast math
>
> Just a suggestion, I'm not sure whether that would be the best breakdown. Perhaps we can also see what the defaults are for GCC and unify with those?

GCC doesn't support "on" so I'm not sure it's possible to distinguish their intentions. I think it would be better to define what we think is best for clang and encourage GCC to unify with that.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D74436/new/

https://reviews.llvm.org/D74436