[PATCH] D137329: [flang] Add -f[no-]associative-math and -mreassociate

[Kiran Chandramohan via Phabricator via cfe-commits]

kiranchandramohan added a comment.

In D137329#3909943 <https://reviews.llvm.org/D137329#3909943>, @awarzynski wrote:

> In D137329#3909082 <https://reviews.llvm.org/D137329#3909082>, @clementval wrote:
>
>> Wouldn't it be good to have a RFC for all these options and what they will do in Flang instead of just adding them all? Or did I miss the RFC?
>
> +1

Fast Math attributes supported in LLVM IR are documented in https://llvm.org/docs/LangRef.html#fast-math-flags. This set of patches (details below) provides a way to set or unset each of these attributes.

While making policy decisions about these flags, like for ffp-contract, we have created an RFC (https://discourse.llvm.org/t/rfc-ffp-contract-default-value/66301).  When adding umbrella flags like -ffast-math/-Ofast/-ffp-model/-funsafe-math-optimizations, we will submit RFCs.

Patch : Flag Name : LLVM IR Attribute
https://reviews.llvm.org/D137325 : f[no-]honor-nans        : nnan
https://reviews.llvm.org/D137072 : f[no-]honor-infinities  : ninf
https://reviews.llvm.org/D137328 : f[no-]signed-zeros      : nsz
https://reviews.llvm.org/D137330 : f[no-]reciprocal-math : arcp
https://reviews.llvm.org/D136080 : ffp-contract option     : contract
https://reviews.llvm.org/D137326 : f[no-]approx-func        : afn
https://reviews.llvm.org/D137329 : f[no-]associative-math: reassoc


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D137329/new/

https://reviews.llvm.org/D137329