Add an initial version of the CompleteBUDataStructures class, which is currently

identical to the BU pass, but has an accurate call graph

llvm-svn: 9956

llvm/lib/Analysis/DataStructure/CompleteBottomUp.cpp

+//===- CompleteBottomUp.cpp - Complete Bottom-Up Data Structure Graphs ----===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+//
+// This is the exact same as the bottom-up graphs, but we use take a completed
+// call graph and inline all indirect callees into their callers graphs, making
+// the result more useful for things like pool allocation.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/DataStructure.h"
+#include "llvm/Module.h"
+#include "llvm/Analysis/DSGraph.h"
+using namespace llvm;
+
+namespace {
+  RegisterAnalysis<CompleteBUDataStructures>
+  X("cbudatastructure", "'Complete' Bottom-up Data Structure Analysis");
+}
+
+using namespace DS;
+
+// run - Calculate the bottom up data structure graphs for each function in the
+// program.
+//
+bool CompleteBUDataStructures::run(Module &M) {
+  BUDataStructures &BU = getAnalysis<BUDataStructures>();
+  GlobalsGraph = new DSGraph(BU.getGlobalsGraph());
+  GlobalsGraph->setPrintAuxCalls();
+
+  // Our call graph is the same as the BU data structures call graph
+  ActualCallees = BU.getActualCallees();
+
+#if 1   // REMOVE ME EVENTUALLY
+  // FIXME: TEMPORARY (remove once finalization of indirect call sites in the
+  // globals graph has been implemented in the BU pass)
+  TDDataStructures &TD = getAnalysis<TDDataStructures>();
+
+  // The call graph extractable from the TD pass is _much more complete_ and
+  // trustable than that generated by the BU pass so far.  Until this is fixed,
+  // we hack it like this:
+  for (Module::iterator MI = M.begin(), ME = M.end(); MI != ME; ++MI) {
+    if (MI->isExternal()) continue;
+    const std::vector<DSCallSite> &CSs = TD.getDSGraph(*MI).getFunctionCalls();
+
+    for (unsigned CSi = 0, e = CSs.size(); CSi != e; ++CSi) {
+      if (CSs[CSi].isIndirectCall()) {
+        Instruction *TheCall = CSs[CSi].getCallSite().getInstruction();
+
+        const std::vector<GlobalValue*> &Callees =
+          CSs[CSi].getCalleeNode()->getGlobals();
+        for (unsigned i = 0, e = Callees.size(); i != e; ++i)
+          if (Function *F = dyn_cast<Function>(Callees[i]))
+            ActualCallees.insert(std::make_pair(TheCall, F));
+      }
+    }
+  }
+#endif
+
+  // Start by copying all of the BU data structures graphs over, verbatim.
+  for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
+    if (!I->isExternal()) {
+      DSInfo[I] = new DSGraph(BU.getDSGraph(*I));
+      DSInfo[I]->setGlobalsGraph(GlobalsGraph);
+      DSInfo[I]->setPrintAuxCalls();
+    }
+
+
+  return false;
+}