[llvm] e76037d - [llvm] Remove unused file MaximumSpanningTree.h

[Nico Weber via llvm-commits]

Author: Nico Weber
Date: 2022-02-10T21:01:24-05:00
New Revision: e76037db44a718827d6e0e7fa257cd321e946c54

URL: https://github.com/llvm/llvm-project/commit/e76037db44a718827d6e0e7fa257cd321e946c54
DIFF: https://github.com/llvm/llvm-project/commit/e76037db44a718827d6e0e7fa257cd321e946c54.diff

LOG: [llvm] Remove unused file MaximumSpanningTree.h

The last use of this file was removed in late 2013 in ea564946251e.
The last use was in PathProfiling.cpp, which had an overview comment
of the overall approach.

Similar functionality lives in the slight more cryptically named
CFGMST.h in this same directory. A similar overview comment is
in PGOInstrumentation.cpp.

No behavior change.

Added: 
    

Modified: 
    

Removed: 
    llvm/lib/Transforms/Instrumentation/MaximumSpanningTree.h


################################################################################
diff  --git a/llvm/lib/Transforms/Instrumentation/MaximumSpanningTree.h b/llvm/lib/Transforms/Instrumentation/MaximumSpanningTree.h
deleted file mode 100644
index 892a6a26da91b..0000000000000
--- a/llvm/lib/Transforms/Instrumentation/MaximumSpanningTree.h
+++ /dev/null
@@ -1,109 +0,0 @@
-//===- llvm/Analysis/MaximumSpanningTree.h - Interface ----------*- C++ -*-===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-//
-// This module provides means for calculating a maximum spanning tree for a
-// given set of weighted edges. The type parameter T is the type of a node.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef LLVM_LIB_TRANSFORMS_INSTRUMENTATION_MAXIMUMSPANNINGTREE_H
-#define LLVM_LIB_TRANSFORMS_INSTRUMENTATION_MAXIMUMSPANNINGTREE_H
-
-#include "llvm/ADT/EquivalenceClasses.h"
-#include "llvm/IR/BasicBlock.h"
-#include <algorithm>
-#include <vector>
-
-namespace llvm {
-
-  /// MaximumSpanningTree - A MST implementation.
-  /// The type parameter T determines the type of the nodes of the graph.
-  template <typename T>
-  class MaximumSpanningTree {
-  public:
-    typedef std::pair<const T*, const T*> Edge;
-    typedef std::pair<Edge, double> EdgeWeight;
-    typedef std::vector<EdgeWeight> EdgeWeights;
-  protected:
-    typedef std::vector<Edge> MaxSpanTree;
-
-    MaxSpanTree MST;
-
-  private:
-    // A comparing class for comparing weighted edges.
-    struct EdgeWeightCompare {
-      static bool getBlockSize(const T *X) {
-        const BasicBlock *BB = dyn_cast_or_null<BasicBlock>(X);
-        return BB ? BB->size() : 0;
-      }
-
-      bool operator()(EdgeWeight X, EdgeWeight Y) const {
-        if (X.second > Y.second) return true;
-        if (X.second < Y.second) return false;
-
-        // Equal edge weights: break ties by comparing block sizes.
-        size_t XSizeA = getBlockSize(X.first.first);
-        size_t YSizeA = getBlockSize(Y.first.first);
-        if (XSizeA > YSizeA) return true;
-        if (XSizeA < YSizeA) return false;
-
-        size_t XSizeB = getBlockSize(X.first.second);
-        size_t YSizeB = getBlockSize(Y.first.second);
-        if (XSizeB > YSizeB) return true;
-        if (XSizeB < YSizeB) return false;
-
-        return false;
-      }
-    };
-
-  public:
-    static char ID; // Class identification, replacement for typeinfo
-
-    /// MaximumSpanningTree() - Takes a vector of weighted edges and returns a
-    /// spanning tree.
-    MaximumSpanningTree(EdgeWeights &EdgeVector) {
-      llvm::stable_sort(EdgeVector, EdgeWeightCompare());
-
-      // Create spanning tree, Forest contains a special data structure
-      // that makes checking if two nodes are already in a common (sub-)tree
-      // fast and cheap.
-      EquivalenceClasses<const T*> Forest;
-      for (typename EdgeWeights::iterator EWi = EdgeVector.begin(),
-           EWe = EdgeVector.end(); EWi != EWe; ++EWi) {
-        Edge e = (*EWi).first;
-
-        Forest.insert(e.first);
-        Forest.insert(e.second);
-      }
-
-      // Iterate over the sorted edges, biggest first.
-      for (typename EdgeWeights::iterator EWi = EdgeVector.begin(),
-           EWe = EdgeVector.end(); EWi != EWe; ++EWi) {
-        Edge e = (*EWi).first;
-
-        if (Forest.findLeader(e.first) != Forest.findLeader(e.second)) {
-          Forest.unionSets(e.first, e.second);
-          // So we know now that the edge is not already in a subtree, so we push
-          // the edge to the MST.
-          MST.push_back(e);
-        }
-      }
-    }
-
-    typename MaxSpanTree::iterator begin() {
-      return MST.begin();
-    }
-
-    typename MaxSpanTree::iterator end() {
-      return MST.end();
-    }
-  };
-
-} // End llvm namespace
-
-#endif // LLVM_LIB_TRANSFORMS_INSTRUMENTATION_MAXIMUMSPANNINGTREE_H