[llvm] [AMDGPU] Legalize fminimum and fmaximum for gfx950 (PR #138971)

[Mariusz Sikora via llvm-commits]

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@@ -861,6 +861,22 @@ SITargetLowering::SITargetLowering(const TargetMachine &TM,
   if (Subtarget->hasIEEEMinMax()) {
     setOperationAction({ISD::FMAXIMUM, ISD::FMINIMUM},
                        {MVT::f16, MVT::f32, MVT::f64, MVT::v2f16}, Legal);
+  } else {
+    // FIXME: For nnan fmaximum, emit the fmaximum3 instead of fmaxnum
+    if (Subtarget->hasMinimum3Maximum3F32())
+      setOperationAction({ISD::FMAXIMUM, ISD::FMINIMUM}, MVT::f32, Legal);
+
+    if (Subtarget->hasMinimum3Maximum3PKF16()) {
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mariusz-sikora-at-amd wrote:

The same code is added in L888 which is under else of `if (Subtarget->hasVOP3PInsts())`. Probably we should remove code from L888 and L892

https://github.com/llvm/llvm-project/pull/138971