[llvm] [GlobalISel] Add GIHasOneUse builtin for combiner match patterns (PR #221804)

[Matt Arsenault via llvm-commits]

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@@ -2234,6 +2229,9 @@ bool CombineRuleBuilder::emitCodeGenInstructionMatchPattern(
   IM.addPredicate<InstructionOpcodeMatcher>(&P.getInst());
   declareInstExpansion(CE, IM, P.getName());
 
+  if (P.hasOneUse())
+    IM.addPredicate<OneUsePredicateMatcher>();
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arsenm wrote:

Why did OneUsePredicateMatcher already exist?

https://github.com/llvm/llvm-project/pull/221804