1 files changed, 83 insertions, 0 deletions
diff --git a/contrib/llvm/lib/CodeGen/MachineLoopInfo.cpp b/contrib/llvm/lib/CodeGen/MachineLoopInfo.cpp
new file mode 100644
index 000000000000..189cb2ba5d1d
--- /dev/null
+++ b/contrib/llvm/lib/CodeGen/MachineLoopInfo.cpp
@@ -0,0 +1,83 @@
+//===- MachineLoopInfo.cpp - Natural Loop Calculator ----------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the MachineLoopInfo class that is used to identify natural
+// loops and determine the loop depth of various nodes of the CFG.  Note that
+// the loops identified may actually be several natural loops that share the 
+// same header node... not just a single natural loop.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CodeGen/MachineLoopInfo.h"
+#include "llvm/CodeGen/MachineDominators.h"
+#include "llvm/CodeGen/Passes.h"
+#include "llvm/Support/Debug.h"
+using namespace llvm;
+
+namespace llvm {
+#define MLB class LoopBase<MachineBasicBlock, MachineLoop>
+TEMPLATE_INSTANTIATION(MLB);
+#undef MLB
+#define MLIB class LoopInfoBase<MachineBasicBlock, MachineLoop>
+TEMPLATE_INSTANTIATION(MLIB);
+#undef MLIB
+}
+
+char MachineLoopInfo::ID = 0;
+INITIALIZE_PASS_BEGIN(MachineLoopInfo, "machine-loops",
+                "Machine Natural Loop Construction", true, true)
+INITIALIZE_PASS_DEPENDENCY(MachineDominatorTree)
+INITIALIZE_PASS_END(MachineLoopInfo, "machine-loops",
+                "Machine Natural Loop Construction", true, true)
+
+char &llvm::MachineLoopInfoID = MachineLoopInfo::ID;
+
+bool MachineLoopInfo::runOnMachineFunction(MachineFunction &) {
+  releaseMemory();
+  LI.Calculate(getAnalysis<MachineDominatorTree>().getBase());    // Update
+  return false;
+}
+
+void MachineLoopInfo::getAnalysisUsage(AnalysisUsage &AU) const {
+  AU.setPreservesAll();
+  AU.addRequired<MachineDominatorTree>();
+  MachineFunctionPass::getAnalysisUsage(AU);
+}
+
+MachineBasicBlock *MachineLoop::getTopBlock() {
+  MachineBasicBlock *TopMBB = getHeader();
+  MachineFunction::iterator Begin = TopMBB->getParent()->begin();
+  if (TopMBB != Begin) {
+    MachineBasicBlock *PriorMBB = prior(MachineFunction::iterator(TopMBB));
+    while (contains(PriorMBB)) {
+      TopMBB = PriorMBB;
+      if (TopMBB == Begin) break;
+      PriorMBB = prior(MachineFunction::iterator(TopMBB));
+    }
+  }
+  return TopMBB;
+}
+
+MachineBasicBlock *MachineLoop::getBottomBlock() {
+  MachineBasicBlock *BotMBB = getHeader();
+  MachineFunction::iterator End = BotMBB->getParent()->end();
+  if (BotMBB != prior(End)) {
+    MachineBasicBlock *NextMBB = llvm::next(MachineFunction::iterator(BotMBB));
+    while (contains(NextMBB)) {
+      BotMBB = NextMBB;
+      if (BotMBB == llvm::next(MachineFunction::iterator(BotMBB))) break;
+      NextMBB = llvm::next(MachineFunction::iterator(BotMBB));
+    }
+  }
+  return BotMBB;
+}
+
+void MachineLoop::dump() const {
+  print(dbgs());
+}