[PATCH] D73588: AMDGPU: Enhancement on FDIV lowering in AMDGPUCodeGenPrepare

[Changpeng Fang via Phabricator via llvm-commits]

cfang marked 2 inline comments as done.
cfang added inline comments.


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Comment at: llvm/lib/Target/AMDGPU/AMDGPUCodeGenPrepare.cpp:714
   const bool UseFDivFast = Ty->isFloatTy() && !NeedHighAccuracy &&
-                           !FastUnsafeRcpLegal;
+                           !CanReassociateFDiv;
 
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arsenm wrote:
> fdiv.fast doesn't' care about the reassociation
You are right. This is just the optimization priority issue.

If we can reassociate fdiv, x/y -> x * rcp(y) is faster than fdiv.fast so we don't do fdiv.fast.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D73588/new/

https://reviews.llvm.org/D73588