[llvm] [AMDGPU][MC]FMA-mix instructions should not be supported in GFX908 etc. (PR #109873)

[Stanislav Mekhanoshin via llvm-commits]

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@@ -1426,7 +1425,6 @@ def FeatureISAVersion9_4_Common : FeatureSet<
   [FeatureGFX9,
    FeatureGFX90AInsts,
    FeatureGFX940Insts,
-   FeatureFmaMixInsts,
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rampitec wrote:

I don't think it shall be fixed. It is really fma, not mad. That is a bad naming choice in the ISA doc. In particular if fixed like that you will get wrong selection (check `SITargetLowering::isFPExtFoldable`).

https://github.com/llvm/llvm-project/pull/109873