[llvm] [LVI][SCCP] Avoid copying ValueLatticeElement (PR #163901)

[Yingwei Zheng via llvm-commits]

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@@ -634,11 +634,11 @@ class SCCPInstVisitor : public InstVisitor<SCCPInstVisitor> {
   /// Merge \p MergeWithV into \p IV and push \p V to the worklist, if \p IV
   /// changes.
   bool mergeInValue(ValueLatticeElement &IV, Value *V,
-                    ValueLatticeElement MergeWithV,
+                    const ValueLatticeElement &MergeWithV,
                     ValueLatticeElement::MergeOptions Opts = {
                         /*MayIncludeUndef=*/false, /*CheckWiden=*/false});
 
-  bool mergeInValue(Value *V, ValueLatticeElement MergeWithV,
+  bool mergeInValue(Value *V, const ValueLatticeElement &MergeWithV,
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dtcxzyw wrote:

I have removed the helper function to avoid implicit invalidations. Hopefully it makes the implementation cleaner.


https://github.com/llvm/llvm-project/pull/163901