* Rename UnlinkUndistinguishableShadowNodes & RemoveUnreachableShadowNodes
to reflect that they can eliminate arbitrary nodes.
* Rename the ShadowNodeEliminate.cpp file to EliminateNodes.cpp for the
same reason
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@2020 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/DataStructure/EliminateNodes.cpp b/lib/Analysis/DataStructure/EliminateNodes.cpp
index 39fdd2c..471c628 100644
--- a/lib/Analysis/DataStructure/EliminateNodes.cpp
+++ b/lib/Analysis/DataStructure/EliminateNodes.cpp
@@ -1,16 +1,17 @@
-//===- ShadowNodeEliminate.cpp - Optimize away shadow nodes ---------------===//
+//===- EliminateNodes.cpp - Prune unneccesary nodes in the graph ----------===//
//
-// This file contains two shadow node optimizations:
-// 1. UnlinkUndistinguishableShadowNodes - Often, after unification, shadow
+// This file contains two node optimizations:
+// 1. UnlinkUndistinguishableNodes - Often, after unification, shadow
// nodes are left around that should not exist anymore. An example is when
// a shadow gets unified with a 'new' node, the following graph gets
// generated: %X -> Shadow, %X -> New. Since all of the edges to the
// shadow node also all go to the New node, we can eliminate the shadow.
//
-// 2. RemoveUnreachableShadowNodes - Remove shadow nodes that are not
-// reachable from some other node in the graph. Unreachable shadow nodes
-// are left lying around because other transforms don't go to the trouble
-// or removing them, since this pass exists.
+// 2. RemoveUnreachableNodes - Remove shadow and allocation nodes that are not
+// reachable from some other node in the graph. Unreachable nodes are left
+// lying around often because a method only refers to some allocations with
+// scalar values or an alloca, then when it is inlined, these references
+// disappear and the nodes become homeless and prunable.
//
//===----------------------------------------------------------------------===//
@@ -57,7 +58,7 @@
// has exactly the same incoming links to it and if the node considers itself
// to be the same as the other node...
//
-bool isIndistinguishableNode(DSNode *DN) {
+static bool isIndistinguishableNode(DSNode *DN) {
if (DN->getReferrers().empty()) { // No referrers...
if (isa<ShadowDSNode>(DN) || isa<AllocDSNode>(DN))
return true; // Node is trivially dead
@@ -127,10 +128,10 @@
return Changed;
}
-// UnlinkUndistinguishableShadowNodes - Eliminate shadow nodes that are not
+// UnlinkUndistinguishableNodes - Eliminate shadow nodes that are not
// distinguishable from some other node in the graph...
//
-bool FunctionDSGraph::UnlinkUndistinguishableShadowNodes() {
+bool FunctionDSGraph::UnlinkUndistinguishableNodes() {
// Loop over all of the shadow nodes, checking to see if they are
// indistinguishable from some other node. If so, eliminate the node!
//
@@ -192,7 +193,7 @@
AllocNodes, ReachableAllocNodes);
}
-bool FunctionDSGraph::RemoveUnreachableShadowNodes() {
+bool FunctionDSGraph::RemoveUnreachableNodes() {
bool Changed = false;
while (1) {