1 files changed, 128 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Transforms/Utils/CloneLoop.cpp b/contrib/llvm/lib/Transforms/Utils/CloneLoop.cpp
new file mode 100644
index 0000000..87dd141
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+++ b/contrib/llvm/lib/Transforms/Utils/CloneLoop.cpp
@@ -0,0 +1,128 @@
+//===- CloneLoop.cpp - Clone loop nest ------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the CloneLoop interface which makes a copy of a loop.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Transforms/Utils/Cloning.h"
+#include "llvm/BasicBlock.h"
+#include "llvm/Analysis/LoopPass.h"
+#include "llvm/Analysis/Dominators.h"
+
+
+using namespace llvm;
+
+/// CloneDominatorInfo - Clone a basic block's dominator tree. It is expected
+/// that the basic block is already cloned.
+static void CloneDominatorInfo(BasicBlock *BB, 
+                               ValueToValueMapTy &VMap,
+                               DominatorTree *DT) {
+
+  assert (DT && "DominatorTree is not available");
+  ValueToValueMapTy::iterator BI = VMap.find(BB);
+  assert (BI != VMap.end() && "BasicBlock clone is missing");
+  BasicBlock *NewBB = cast<BasicBlock>(BI->second);
+
+  // NewBB already got dominator info.
+  if (DT->getNode(NewBB))
+    return;
+
+  assert (DT->getNode(BB) && "BasicBlock does not have dominator info");
+  // Entry block is not expected here. Infinite loops are not to cloned.
+  assert (DT->getNode(BB)->getIDom() && "BasicBlock does not have immediate dominator");
+  BasicBlock *BBDom = DT->getNode(BB)->getIDom()->getBlock();
+
+  // NewBB's dominator is either BB's dominator or BB's dominator's clone.
+  BasicBlock *NewBBDom = BBDom;
+  ValueToValueMapTy::iterator BBDomI = VMap.find(BBDom);
+  if (BBDomI != VMap.end()) {
+    NewBBDom = cast<BasicBlock>(BBDomI->second);
+    if (!DT->getNode(NewBBDom))
+      CloneDominatorInfo(BBDom, VMap, DT);
+  }
+  DT->addNewBlock(NewBB, NewBBDom);
+}
+
+/// CloneLoop - Clone Loop. Clone dominator info. Populate VMap
+/// using old blocks to new blocks mapping.
+Loop *llvm::CloneLoop(Loop *OrigL, LPPassManager  *LPM, LoopInfo *LI,
+                      ValueToValueMapTy &VMap, Pass *P) {
+  
+  DominatorTree *DT = NULL;
+  if (P)
+    DT = P->getAnalysisIfAvailable<DominatorTree>();
+
+  SmallVector<BasicBlock *, 16> NewBlocks;
+
+  // Populate loop nest.
+  SmallVector<Loop *, 8> LoopNest;
+  LoopNest.push_back(OrigL);
+
+
+  Loop *NewParentLoop = NULL;
+  do {
+    Loop *L = LoopNest.pop_back_val();
+    Loop *NewLoop = new Loop();
+
+    if (!NewParentLoop)
+      NewParentLoop = NewLoop;
+
+    LPM->insertLoop(NewLoop, L->getParentLoop());
+
+    // Clone Basic Blocks.
+    for (Loop::block_iterator I = L->block_begin(), E = L->block_end();
+         I != E; ++I) {
+      BasicBlock *BB = *I;
+      BasicBlock *NewBB = CloneBasicBlock(BB, VMap, ".clone");
+      VMap[BB] = NewBB;
+      if (P)
+        LPM->cloneBasicBlockSimpleAnalysis(BB, NewBB, L);
+      NewLoop->addBasicBlockToLoop(NewBB, LI->getBase());
+      NewBlocks.push_back(NewBB);
+    }
+
+    // Clone dominator info.
+    if (DT)
+      for (Loop::block_iterator I = L->block_begin(), E = L->block_end();
+           I != E; ++I) {
+        BasicBlock *BB = *I;
+        CloneDominatorInfo(BB, VMap, DT);
+      }
+
+    // Process sub loops
+    for (Loop::iterator I = L->begin(), E = L->end(); I != E; ++I)
+      LoopNest.push_back(*I);
+  } while (!LoopNest.empty());
+
+  // Remap instructions to reference operands from VMap.
+  for(SmallVector<BasicBlock *, 16>::iterator NBItr = NewBlocks.begin(), 
+        NBE = NewBlocks.end();  NBItr != NBE; ++NBItr) {
+    BasicBlock *NB = *NBItr;
+    for(BasicBlock::iterator BI = NB->begin(), BE = NB->end(); 
+        BI != BE; ++BI) {
+      Instruction *Insn = BI;
+      for (unsigned index = 0, num_ops = Insn->getNumOperands(); 
+           index != num_ops; ++index) {
+        Value *Op = Insn->getOperand(index);
+        ValueToValueMapTy::iterator OpItr = VMap.find(Op);
+        if (OpItr != VMap.end())
+          Insn->setOperand(index, OpItr->second);
+      }
+    }
+  }
+
+  BasicBlock *Latch = OrigL->getLoopLatch();
+  Function *F = Latch->getParent();
+  F->getBasicBlockList().insert(OrigL->getHeader(), 
+                                NewBlocks.begin(), NewBlocks.end());
+
+
+  return NewParentLoop;
+}