[PATCH] D40696: Enable aggressive FMA on T99 and provide AArch64 option for other micro-arch's

[Florian Hahn via Phabricator via llvm-commits]

fhahn added inline comments.


================
Comment at: lib/Target/AArch64/AArch64.td:152
 
+def FeatureAggressiveFMAFloat :
+  SubtargetFeature<"aggressive-fma-float",
----------------
steleman wrote:
> fhahn wrote:
> > How likely is it that we aggressive FMA is beneficial for floats or double only? IMO it's probably enough to just have `-aggressive-fma` for now.
> 
> Could you please clarify this? I.e. are you referring to quad-precision?
> 
> T99 doesn't have quad-precision FMA. Only floats and doubles. Are there any AArch64 micro-arch'es that can do quad-precision FMA?
> 
> Or are you asking about SIMD?
> 
> 
Sorry, I meant I think a single option to enable aggressive FMA would be enough and separate options for float and double seems too fine grained, unless I am missing something :)


Repository:
  rL LLVM

https://reviews.llvm.org/D40696