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diff --git a/lib/Transforms/Utils/DemoteRegToStack.cpp b/lib/Transforms/Utils/DemoteRegToStack.cpp
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+++ b/lib/Transforms/Utils/DemoteRegToStack.cpp
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+//===- DemoteRegToStack.cpp - Move a virtual register to the stack --------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file provide the function DemoteRegToStack().  This function takes a
+// virtual register computed by an Instruction and replaces it with a slot in
+// the stack frame, allocated via alloca. It returns the pointer to the
+// AllocaInst inserted.  After this function is called on an instruction, we are
+// guaranteed that the only user of the instruction is a store that is
+// immediately after it.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Transforms/Utils/Local.h"
+#include "llvm/Function.h"
+#include "llvm/Instructions.h"
+#include "llvm/Type.h"
+#include <map>
+using namespace llvm;
+
+/// DemoteRegToStack - This function takes a virtual register computed by an
+/// Instruction and replaces it with a slot in the stack frame, allocated via
+/// alloca.  This allows the CFG to be changed around without fear of
+/// invalidating the SSA information for the value.  It returns the pointer to
+/// the alloca inserted to create a stack slot for I.
+///
+AllocaInst* llvm::DemoteRegToStack(Instruction &I, bool VolatileLoads,
+                                   Instruction *AllocaPoint) {
+  if (I.use_empty()) {
+    I.eraseFromParent();
+    return 0;
+  }
+  
+  // Create a stack slot to hold the value.
+  AllocaInst *Slot;
+  if (AllocaPoint) {
+    Slot = new AllocaInst(I.getType(), 0, I.getName()+".reg2mem", AllocaPoint);
+  } else {
+    Function *F = I.getParent()->getParent();
+    Slot = new AllocaInst(I.getType(), 0, I.getName()+".reg2mem",
+                          F->getEntryBlock().begin());
+  }
+  
+  // Change all of the users of the instruction to read from the stack slot
+  // instead.
+  while (!I.use_empty()) {
+    Instruction *U = cast<Instruction>(I.use_back());
+    if (PHINode *PN = dyn_cast<PHINode>(U)) {
+      // If this is a PHI node, we can't insert a load of the value before the
+      // use.  Instead, insert the load in the predecessor block corresponding
+      // to the incoming value.
+      //
+      // Note that if there are multiple edges from a basic block to this PHI
+      // node that we cannot multiple loads.  The problem is that the resultant
+      // PHI node will have multiple values (from each load) coming in from the
+      // same block, which is illegal SSA form.  For this reason, we keep track
+      // and reuse loads we insert.
+      std::map<BasicBlock*, Value*> Loads;
+      for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
+        if (PN->getIncomingValue(i) == &I) {
+          Value *&V = Loads[PN->getIncomingBlock(i)];
+          if (V == 0) {
+            // Insert the load into the predecessor block
+            V = new LoadInst(Slot, I.getName()+".reload", VolatileLoads, 
+                             PN->getIncomingBlock(i)->getTerminator());
+          }
+          PN->setIncomingValue(i, V);
+        }
+
+    } else {
+      // If this is a normal instruction, just insert a load.
+      Value *V = new LoadInst(Slot, I.getName()+".reload", VolatileLoads, U);
+      U->replaceUsesOfWith(&I, V);
+    }
+  }
+
+
+  // Insert stores of the computed value into the stack slot.  We have to be
+  // careful is I is an invoke instruction though, because we can't insert the
+  // store AFTER the terminator instruction.
+  BasicBlock::iterator InsertPt;
+  if (!isa<TerminatorInst>(I)) {
+    InsertPt = &I;
+    ++InsertPt;
+  } else {
+    // We cannot demote invoke instructions to the stack if their normal edge
+    // is critical.
+    InvokeInst &II = cast<InvokeInst>(I);
+    assert(II.getNormalDest()->getSinglePredecessor() &&
+           "Cannot demote invoke with a critical successor!");
+    InsertPt = II.getNormalDest()->begin();
+  }
+
+  for (; isa<PHINode>(InsertPt); ++InsertPt)
+  /* empty */;   // Don't insert before any PHI nodes.
+  new StoreInst(&I, Slot, InsertPt);
+
+  return Slot;
+}
+
+
+/// DemotePHIToStack - This function takes a virtual register computed by a phi
+/// node and replaces it with a slot in the stack frame, allocated via alloca.
+/// The phi node is deleted and it returns the pointer to the alloca inserted.
+AllocaInst* llvm::DemotePHIToStack(PHINode *P, Instruction *AllocaPoint) {
+  if (P->use_empty()) {
+    P->eraseFromParent();    
+    return 0;                
+  }
+
+  // Create a stack slot to hold the value.
+  AllocaInst *Slot;
+  if (AllocaPoint) {
+    Slot = new AllocaInst(P->getType(), 0, P->getName()+".reg2mem", AllocaPoint);
+  } else {
+    Function *F = P->getParent()->getParent();
+    Slot = new AllocaInst(P->getType(), 0, P->getName()+".reg2mem",
+                          F->getEntryBlock().begin());
+  }
+  
+  // Iterate over each operand, insert store in each predecessor.
+  for (unsigned i = 0, e = P->getNumIncomingValues(); i < e; ++i) {
+    if (InvokeInst *II = dyn_cast<InvokeInst>(P->getIncomingValue(i))) {
+      assert(II->getParent() != P->getIncomingBlock(i) && 
+             "Invoke edge not supported yet"); II=II;
+    }
+    new StoreInst(P->getIncomingValue(i), Slot, 
+                  P->getIncomingBlock(i)->getTerminator());
+  }
+  
+  // Insert load in place of the phi and replace all uses.
+  Value *V = new LoadInst(Slot, P->getName()+".reload", P);
+  P->replaceAllUsesWith(V);
+  
+  // Delete phi.
+  P->eraseFromParent();
+  
+  return Slot;
+}