[llvm] [CodeGen] expand-fp: Change frem expansion criterion (PR #158285)

[Ulrich Weigand via llvm-commits]

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@@ -587,7 +587,7 @@ SystemZTargetLowering::SystemZTargetLowering(const TargetMachine &TM,
       setOperationAction(ISD::FSIN, VT, Expand);
       setOperationAction(ISD::FCOS, VT, Expand);
       setOperationAction(ISD::FSINCOS, VT, Expand);
-      setOperationAction(ISD::FREM, VT, Expand);
+      setOperationAction(ISD::FREM, VT, LibCall);
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uweigand wrote:

I don't mind this particular change, if this is the way we decide to handle this.  It's a bit strange however to handle FREM differently from all the other (potential) libcalls here.  For example, FSINCOS is set to Expand, but that means that common code checks whether a libcall is available and uses it if so (see SelectionDAGLegalize::ExpandNode).

https://github.com/llvm/llvm-project/pull/158285