[PATCH] D26708: Fix -f[no-]reciprocal-math -ffast-math interaction, including LTO

[Warren Ristow via llvm-commits]

wristow added a comment.

In https://reviews.llvm.org/D26708#596664, @hfinkel wrote:

> We might reconsider having 'fast' imply all of the other flags. I believe this was a suboptimal design choice, and so long as someone is willing to do the work to separate out the various semantic requirements, we should allow that work to proceed.


I have to admit I felt "funny" about changing the semantics of whether `fast` should imply all the other flags.  Reconsidering that design choice is what I was implicitly suggesting when I said:

>> To put it another way, rather than an "umbrella" flag such
>>  as fast being checked in the back-end (along with an individual flag like
>>  arcp), it seems to me that just checking the individual flag expresses
>>  the need more cleanly. Any fast-math-related transformation that doesn't
>>  have an individual flag (e.g., re-association currently doesn't), should
>>  eventually have an individual flag defined for it, and then that individual
>>  flag should be checked.

Regarding:

> We should discuss this on llvm-dev first, however.

Sounds good.  I'll start a discussion on llvm-dev.


https://reviews.llvm.org/D26708