[PATCH] D104723: [DAGCombine] Check reassoc flags in aggressive fsub fusion

[Jay Foad via Phabricator via llvm-commits]

foad added inline comments.


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Comment at: llvm/test/CodeGen/AMDGPU/fpext-free.ll:312
 entry:
-  %mul = fmul half %u, %v
+  %mul = fmul reassoc half %u, %v
   %mul.ext = fpext half %mul to float
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I don't think this transform should require "reassoc" on this fmul, should it? `%u * %v` is calculated the same way before and after the transform. Maybe it should require "reassoc" on the call to fmuladd though, because the add does get reassociated with the fsub.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D104723/new/

https://reviews.llvm.org/D104723