[llvm] [TableGen] Add a backend to generate MacroFusion predicators (PR #72222)

[Matt Arsenault via llvm-commits]

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@@ -584,3 +584,116 @@ class MemoryQueue<ProcResourceKind PR> {
 
 class LoadQueue<ProcResourceKind LDQueue> : MemoryQueue<LDQueue>;
 class StoreQueue<ProcResourceKind STQueue> : MemoryQueue<STQueue>;
+
+// The target instruction that FusionPredicate will be evaluated on.
+class FusionTarget;
+def first : FusionTarget;
+def second : FusionTarget;
+def both : FusionTarget;
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arsenm wrote:

These are really general names to introduce into the global namespace; first_fusion_target maybe?

https://github.com/llvm/llvm-project/pull/72222