DomTree: Remove getChildren() accessor

Summary:
Avoid exposing details about how children are stored. This will enable
subsequent type-erasure changes.

New methods are introduced to cover common access patterns.

Change-Id: Idb5f4b1b9c84e4cc71ddb39bb52a388682f5674f

Reviewers: arsenm, RKSimon, mehdi_amini, courbet

Subscribers: qcolombet, sdardis, wdng, hiraditya, jrtc27, zzheng, atanasyan, asbirlea, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D83083

1 files changed, 9 insertions, 9 deletions

diff --git a/llvm/lib/CodeGen/MachineLICM.cpp b/llvm/lib/CodeGen/MachineLICM.cpp
index 98638b9..5e8a916 100644
--- a/llvm/lib/CodeGen/MachineLICM.cpp
+++ b/llvm/lib/CodeGen/MachineLICM.cpp
@@ -737,8 +737,7 @@ void MachineLICMBase::HoistOutOfLoop(MachineDomTreeNode *HeaderN) {
       continue;
 
     Scopes.push_back(Node);
-    const std::vector<MachineDomTreeNode*> &Children = Node->getChildren();
-    unsigned NumChildren = Children.size();
+    unsigned NumChildren = Node->getNumChildren();
 
     // Don't hoist things out of a large switch statement.  This often causes
     // code to be hoisted that wasn't going to be executed, and increases
@@ -747,13 +746,14 @@ void MachineLICMBase::HoistOutOfLoop(MachineDomTreeNode *HeaderN) {
       NumChildren = 0;
 
     OpenChildren[Node] = NumChildren;
-    // Add children in reverse order as then the next popped worklist node is
-    // the first child of this node.  This means we ultimately traverse the
-    // DOM tree in exactly the same order as if we'd recursed.
-    for (int i = (int)NumChildren-1; i >= 0; --i) {
-      MachineDomTreeNode *Child = Children[i];
-      ParentMap[Child] = Node;
-      WorkList.push_back(Child);
+    if (NumChildren) {
+      // Add children in reverse order as then the next popped worklist node is
+      // the first child of this node.  This means we ultimately traverse the
+      // DOM tree in exactly the same order as if we'd recursed.
+      for (MachineDomTreeNode *Child : reverse(Node->children())) {
+        ParentMap[Child] = Node;
+        WorkList.push_back(Child);
+      }
     }
   }