[llvm] [AMDGPU] Filter candidates of LiveRegOptimizer for profitable cases (PR #124624)

[Matt Arsenault via llvm-commits]

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@@ -125,6 +127,131 @@ class LiveRegOptimizer {
     return LK.first != TargetLoweringBase::TypeLegal;
   }
 
+  /// Check if intrinsic natively operates on 8-bit or 16-bit
+  bool isNativeIntrinsic(Intrinsic::ID ID) {
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arsenm wrote:

> compiler assistance to scalarize the code 

Not clear to me what this means. All the vector types will be split or scalarized in some way. The target intrinsics, with a handful of exceptions, only operate on legal types. ``isTargetIntrinsic || isTypeLegal()``?

https://github.com/llvm/llvm-project/pull/124624