[PATCH] D80702: [AMDGPU] Fold llvm.amdgcn.cos and llvm.amdgcn.sin intrinsics

[Jay Foad via Phabricator via llvm-commits]

foad marked an inline comment as done.
foad added inline comments.


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Comment at: llvm/lib/Analysis/ConstantFolding.cpp:1918
+        auto NativeFP = IntrinsicID == Intrinsic::amdgcn_cos ? cos : sin;
+        return ConstantFoldFP(NativeFP, V * 2 * M_PI, Ty);
     }
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This folds amdgcn.sin(1.0) to a very small value that is not exactly 0.0. Should I add an explicit check for all of the quarter-integer values that should fold to exactly -1.0 or 0.0 or +1.0 ?


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D80702/new/

https://reviews.llvm.org/D80702