From 2eff970892e495019a0996c0aa8784450697cd2a Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Sun, 13 Mar 2005 20:15:06 +0000
Subject: After finishing BU analysis, move all global variables from the
 globals graph into main and mark them complete.

llvm-svn: 20583
---
 .../Analysis/DataStructure/CompleteBottomUp.cpp    | 29 +++++++++++++++++++---
 1 file changed, 26 insertions(+), 3 deletions(-)

(limited to 'llvm/lib/Analysis/DataStructure/CompleteBottomUp.cpp')

diff --git a/llvm/lib/Analysis/DataStructure/CompleteBottomUp.cpp b/llvm/lib/Analysis/DataStructure/CompleteBottomUp.cpp
index 1c9e3299d02..77a5f32fa59 100644
--- a/llvm/lib/Analysis/DataStructure/CompleteBottomUp.cpp
+++ b/llvm/lib/Analysis/DataStructure/CompleteBottomUp.cpp
@@ -76,9 +76,10 @@ bool CompleteBUDataStructures::runOnModule(Module &M) {
   hash_map<DSGraph*, unsigned> ValMap;
   unsigned NextID = 1;
 
-  if (Function *Main = M.getMainFunction()) {
-    if (!Main->isExternal())
-      calculateSCCGraphs(getOrCreateGraph(*Main), Stack, NextID, ValMap);
+  Function *MainFunc = M.getMainFunction();
+  if (MainFunc) {
+    if (!MainFunc->isExternal())
+      calculateSCCGraphs(getOrCreateGraph(*MainFunc), Stack, NextID, ValMap);
   } else {
     std::cerr << "CBU-DSA: No 'main' function found!\n";
   }
@@ -88,6 +89,28 @@ bool CompleteBUDataStructures::runOnModule(Module &M) {
       calculateSCCGraphs(getOrCreateGraph(*I), Stack, NextID, ValMap);
 
   GlobalsGraph->removeTriviallyDeadNodes();
+
+
+  // Merge the globals variables (not the calls) from the globals graph back
+  // into the main function's graph so that the main function contains all of
+  // the information about global pools and GV usage in the program.
+  if (MainFunc) {
+    DSGraph &MainGraph = getOrCreateGraph(*MainFunc);
+    const DSGraph &GG = *MainGraph.getGlobalsGraph();
+    ReachabilityCloner RC(MainGraph, GG, 
+                          DSGraph::DontCloneCallNodes |
+                          DSGraph::DontCloneAuxCallNodes);
+
+    // Clone the global nodes into this graph.
+    for (DSScalarMap::global_iterator I = GG.getScalarMap().global_begin(),
+           E = GG.getScalarMap().global_end(); I != E; ++I)
+      if (isa<GlobalVariable>(*I))
+        RC.getClonedNH(GG.getNodeForValue(*I));
+
+    MainGraph.markIncompleteNodes(DSGraph::MarkFormalArgs | 
+                                  DSGraph::IgnoreGlobals);
+  }
+
   return false;
 }
 
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