[llvm] 3f8431e - [SCCIterator] Union MST node by rank correctly (#86389)

[via llvm-commits]

Author: XChy
Date: 2024-03-26T17:31:55+08:00
New Revision: 3f8431ec66ffcfaf1bd864261f425b12ab1b59b8

URL: https://github.com/llvm/llvm-project/commit/3f8431ec66ffcfaf1bd864261f425b12ab1b59b8
DIFF: https://github.com/llvm/llvm-project/commit/3f8431ec66ffcfaf1bd864261f425b12ab1b59b8.diff

LOG: [SCCIterator] Union MST node by rank correctly (#86389)

Fixes #85975

Added: 
    

Modified: 
    llvm/include/llvm/ADT/SCCIterator.h

Removed: 
    


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diff  --git a/llvm/include/llvm/ADT/SCCIterator.h b/llvm/include/llvm/ADT/SCCIterator.h
index e743ae7c11edbc..3bd103c13f19f9 100644
--- a/llvm/include/llvm/ADT/SCCIterator.h
+++ b/llvm/include/llvm/ADT/SCCIterator.h
@@ -281,14 +281,14 @@ class scc_member_iterator {
     if (G1 == G2)
       return false;
 
-    // Make the smaller rank tree a direct child or the root of high rank tree.
-    if (G1->Rank < G1->Rank)
+    // Make the smaller rank tree a direct child of high rank tree.
+    if (G1->Rank < G2->Rank)
       G1->Group = G2;
     else {
       G2->Group = G1;
       // If the ranks are the same, increment root of one tree by one.
       if (G1->Rank == G2->Rank)
-        G2->Rank++;
+        G1->Rank++;
     }
     return true;
   }