1 files changed, 47 insertions, 0 deletions
diff --git a/lib/CodeGen/SplitKit.cpp b/lib/CodeGen/SplitKit.cpp
index 4bb13e44b8..38c9469879 100644
--- a/lib/CodeGen/SplitKit.cpp
+++ b/lib/CodeGen/SplitKit.cpp
@@ -24,6 +24,7 @@
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
+#include "llvm/Support/GraphWriter.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Target/TargetInstrInfo.h"
 #include "llvm/Target/TargetMachine.h"
@@ -35,6 +36,52 @@ AllowSplit("spiller-splits-edges",
            cl::desc("Allow critical edge splitting during spilling"));
 
 //===----------------------------------------------------------------------===//
+//                                 Edge Bundles
+//===----------------------------------------------------------------------===//
+
+/// compute - Compute the edge bundles for MF. Bundles depend only on the CFG.
+void EdgeBundles::compute(const MachineFunction *mf) {
+  MF = mf;
+  EC.clear();
+  EC.grow(2 * MF->size());
+
+  for (MachineFunction::const_iterator I = MF->begin(), E = MF->end(); I != E;
+       ++I) {
+    const MachineBasicBlock &MBB = *I;
+    unsigned OutE = 2 * MBB.getNumber() + 1;
+    // Join the outgoing bundle with the ingoing bundles of all successors.
+    for (MachineBasicBlock::const_succ_iterator SI = MBB.succ_begin(),
+           SE = MBB.succ_end(); SI != SE; ++SI)
+      EC.join(OutE, 2 * (*SI)->getNumber());
+  }
+  EC.compress();
+}
+
+/// view - Visualize the annotated bipartite CFG with Graphviz.
+void EdgeBundles::view() const {
+  ViewGraph(*this, "EdgeBundles");
+}
+
+/// Specialize WriteGraph, the standard implementation won't work.
+raw_ostream &llvm::WriteGraph(raw_ostream &O, const EdgeBundles &G,
+                              bool ShortNames,
+                              const std::string &Title) {
+  const MachineFunction *MF = G.getMachineFunction();
+
+  O << "digraph {\n";
+  for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
+       I != E; ++I) {
+    unsigned BB = I->getNumber();
+    O << "\t\"BB#" << BB << "\" [ shape=box ]\n"
+      << '\t' << G.getBundle(BB, false) << " -> \"BB#" << BB << "\"\n"
+      << "\t\"BB#" << BB << "\" -> " << G.getBundle(BB, true) << '\n';
+  }
+  O << "}\n";
+  return O;
+}
+
+
+//===----------------------------------------------------------------------===//
 //                                 Split Analysis
 //===----------------------------------------------------------------------===//