[llvm] [CodeGen] Preserved additional analyses in StackSlotColoring pass. (PR #93779)

[Matt Arsenault via llvm-commits]

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@@ -152,6 +154,14 @@ namespace {
       AU.addRequired<MachineBlockFrequencyInfo>();
       AU.addPreserved<MachineBlockFrequencyInfo>();
       AU.addPreservedID(MachineDominatorsID);
+
+      // In some Target's pipeline, register allocation (RA) might be
+      // split into multiple phases based on register class. So, this pass
+      // may be invoked multiple times requiring it to save these analyses to be
+      // used by RA later.
+      AU.addPreserved<LiveIntervals>();
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arsenm wrote:

Do you need to `addPreserved<SlotIndexes>`? I'm also surprised you don't need to refer to LiveIntervals to maintain them? 

https://github.com/llvm/llvm-project/pull/93779