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

[Matt Arsenault via llvm-commits]

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@@ -45,6 +46,7 @@ class AMDGPULateCodeGenPrepare
   Function &F;
   const DataLayout &DL;
   const GCNSubtarget &ST;
+  const TargetTransformInfo &TTI;
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arsenm wrote:

Use the target specific subclass 

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