Leaf descendants

[xuanzhang816]

In the current implementation, only leaf children of each internal node in the suffix tree are included as candidates for outlining. But all leaf descendants are outlining candidates, which we include in the new implementation.

For Clang/LLD, it shows around 3% reduction in text segment size when compared to the baseline -Oz linker binary.

[github-actions]

⚠️ C/C++ code formatter, clang-format found issues in your code. ⚠️

You can test this locally with the following command:

git-clang-format --diff b6824c9d459da059e247a60c1ebd1aeb580dacc2 aefc5990acdb745d7d73c571b00424a4c5d41c96 -- llvm/include/llvm/Support/SuffixTree.h llvm/include/llvm/Support/SuffixTreeNode.h llvm/lib/CodeGen/MachineOutliner.cpp llvm/lib/Support/SuffixTree.cpp llvm/lib/Support/SuffixTreeNode.cpp llvm/unittests/Support/SuffixTreeTest.cpp

View the diff from clang-format here.

diff --git a/llvm/include/llvm/Support/SuffixTree.h b/llvm/include/llvm/Support/SuffixTree.h
index 90f8aae60a..37b7366640 100644
--- a/llvm/include/llvm/Support/SuffixTree.h
+++ b/llvm/include/llvm/Support/SuffixTree.h
@@ -205,7 +205,8 @@ public:
     }
 
     RepeatedSubstringIterator(
-        SuffixTreeInternalNode *N, const std::vector<SuffixTreeLeafNode *> &LeafNodes = {})
+        SuffixTreeInternalNode *N,
+        const std::vector<SuffixTreeLeafNode *> &LeafNodes = {})
         : N(N), LeafNodes(LeafNodes) {
       // Do we have a non-null node?
       if (!N)