[llvm] [AMDGPU] Add freeze for LowerSELECT (PR #148796)

[Matt Arsenault via llvm-commits]

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@@ -5569,6 +5569,7 @@ bool SelectionDAG::canCreateUndefOrPoison(SDValue Op, const APInt &DemandedElts,
   case ISD::BUILD_VECTOR:
   case ISD::BUILD_PAIR:
   case ISD::SPLAT_VECTOR:
+  case ISD::FABS:
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arsenm wrote:

This should be done separately 

https://github.com/llvm/llvm-project/pull/148796