[llvm] PowerPC/VSX: Select FMINNUM_IEEE and FMAXNUM_IEEE (PR #112195)

[YunQiang Su via llvm-commits]

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@@ -775,6 +775,10 @@ PPCTargetLowering::PPCTargetLowering(const PPCTargetMachine &TM,
     setOperationAction(ISD::FMAXNUM_IEEE, MVT::f32, Legal);
     setOperationAction(ISD::FMINNUM_IEEE, MVT::f64, Legal);
     setOperationAction(ISD::FMINNUM_IEEE, MVT::f32, Legal);
+    setOperationAction(ISD::FMAXNUM, MVT::f64, Legal);
+    setOperationAction(ISD::FMAXNUM, MVT::f32, Legal);
+    setOperationAction(ISD::FMINNUM, MVT::f64, Legal);
+    setOperationAction(ISD::FMINNUM, MVT::f32, Legal);
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wzssyqa wrote:

> This is beyond what the title suggests. 

It's a bootstrap problem:
If we fix `FMAXNUM_IEEE` only, some of test cases will fail.
The problem is that currently `FMINNUM` is expanded to
   FCANONICALIZE + FCANONICALIZE + FMINNUM_IEEE
while FCANONICALIZE is not defined by here: I will submit it in a future patch.

> Do all subtargets have the ignore signaling behavior, and only vsx has the ieee behavior?

It seems that PowerPC doesn't have min/max operation in its scale part.

https://github.com/llvm/llvm-project/pull/112195