X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FTransforms%2FUtils%2FInlineFunction.cpp;h=69793ab8361de59ec36e2985d3d1cd5b32ff53bf;hb=a3de16bc8f36638d5444e3e7b0112998af54f826;hp=26b4de5d3b144ddd13f68462cf66ea57fffe694c;hpb=dc770929cb2f97397970e2942b746839fc387992;p=oota-llvm.git

diff --git a/lib/Transforms/Utils/InlineFunction.cpp b/lib/Transforms/Utils/InlineFunction.cpp
index 26b4de5d3b1..69793ab8361 100644
--- a/lib/Transforms/Utils/InlineFunction.cpp
+++ b/lib/Transforms/Utils/InlineFunction.cpp
@@ -10,6 +10,13 @@
 // This file implements inlining of a function into a call site, resolving
 // parameters and the return value as appropriate.
 //
+// The code in this file for handling inlines through invoke
+// instructions preserves semantics only under some assumptions about
+// the behavior of unwinders which correspond to gcc-style libUnwind
+// exception personality functions.  Eventually the IR will be
+// improved to make this unnecessary, but until then, this code is
+// marked [LIBUNWIND].
+//
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Transforms/Utils/Cloning.h"
@@ -17,119 +24,252 @@
 #include "llvm/DerivedTypes.h"
 #include "llvm/Module.h"
 #include "llvm/Instructions.h"
+#include "llvm/IntrinsicInst.h"
 #include "llvm/Intrinsics.h"
 #include "llvm/Attributes.h"
 #include "llvm/Analysis/CallGraph.h"
+#include "llvm/Analysis/DebugInfo.h"
+#include "llvm/Analysis/InstructionSimplify.h"
 #include "llvm/Target/TargetData.h"
+#include "llvm/Transforms/Utils/Local.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/Support/CallSite.h"
+#include "llvm/Support/IRBuilder.h"
 using namespace llvm;
 
-bool llvm::InlineFunction(CallInst *CI, CallGraph *CG, const TargetData *TD) {
-  return InlineFunction(CallSite(CI), CG, TD);
+bool llvm::InlineFunction(CallInst *CI, InlineFunctionInfo &IFI) {
+  return InlineFunction(CallSite(CI), IFI);
+}
+bool llvm::InlineFunction(InvokeInst *II, InlineFunctionInfo &IFI) {
+  return InlineFunction(CallSite(II), IFI);
+}
+
+namespace {
+  /// A class for recording information about inlining through an invoke.
+  class InvokeInliningInfo {
+    BasicBlock *UnwindDest;
+    SmallVector<Value*, 8> UnwindDestPHIValues;
+
+  public:
+    InvokeInliningInfo(InvokeInst *II) : UnwindDest(II->getUnwindDest()) {
+      // If there are PHI nodes in the unwind destination block, we
+      // need to keep track of which values came into them from the
+      // invoke before removing the edge from this block.
+      llvm::BasicBlock *InvokeBlock = II->getParent();
+      for (BasicBlock::iterator I = UnwindDest->begin(); isa<PHINode>(I); ++I) {
+        PHINode *PN = cast<PHINode>(I);
+        // Save the value to use for this edge.
+        llvm::Value *Incoming = PN->getIncomingValueForBlock(InvokeBlock);
+        UnwindDestPHIValues.push_back(Incoming);
+      }
+    }
+
+    BasicBlock *getUnwindDest() const {
+      return UnwindDest;
+    }
+
+    /// Add incoming-PHI values to the unwind destination block for
+    /// the given basic block, using the values for the original
+    /// invoke's source block.
+    void addIncomingPHIValuesFor(BasicBlock *BB) const {
+      BasicBlock::iterator I = UnwindDest->begin();
+      for (unsigned i = 0, e = UnwindDestPHIValues.size(); i != e; ++i, ++I) {
+        PHINode *PN = cast<PHINode>(I);
+        PN->addIncoming(UnwindDestPHIValues[i], BB);
+      }
+    }
+  };
 }
-bool llvm::InlineFunction(InvokeInst *II, CallGraph *CG, const TargetData *TD) {
-  return InlineFunction(CallSite(II), CG, TD);
+
+/// [LIBUNWIND] Check whether the given value is the _Unwind_Resume
+/// function specified by the Itanium EH ABI.
+static bool isUnwindResume(Value *value) {
+  Function *fn = dyn_cast<Function>(value);
+  if (!fn) return false;
+
+  // declare void @_Unwind_Resume(i8*)
+  if (fn->getName() != "_Unwind_Resume") return false;
+  const FunctionType *fnType = fn->getFunctionType();
+  if (!fnType->getReturnType()->isVoidTy()) return false;
+  if (fnType->isVarArg()) return false;
+  if (fnType->getNumParams() != 1) return false;
+  const PointerType *paramType = dyn_cast<PointerType>(fnType->getParamType(0));
+  return (paramType && paramType->getElementType()->isIntegerTy(8));
+}
+
+/// [LIBUNWIND] Find the (possibly absent) call to @llvm.eh.selector in
+/// the given landing pad.
+static EHSelectorInst *findSelectorForLandingPad(BasicBlock *lpad) {
+  for (BasicBlock::iterator i = lpad->begin(), e = lpad->end(); i != e; i++)
+    if (EHSelectorInst *selector = dyn_cast<EHSelectorInst>(i))
+      return selector;
+  return 0;
 }
 
+/// [LIBUNWIND] Check whether this selector is "only cleanups":
+///   call i32 @llvm.eh.selector(blah, blah, i32 0)
+static bool isCleanupOnlySelector(EHSelectorInst *selector) {
+  if (selector->getNumArgOperands() != 3) return false;
+  ConstantInt *val = dyn_cast<ConstantInt>(selector->getArgOperand(2));
+  return (val && val->isZero());
+}
+
+/// HandleCallsInBlockInlinedThroughInvoke - When we inline a basic block into
+/// an invoke, we have to turn all of the calls that can throw into
+/// invokes.  This function analyze BB to see if there are any calls, and if so,
+/// it rewrites them to be invokes that jump to InvokeDest and fills in the PHI
+/// nodes in that block with the values specified in InvokeDestPHIValues.
+///
+/// Returns true to indicate that the next block should be skipped.
+static bool HandleCallsInBlockInlinedThroughInvoke(BasicBlock *BB,
+                                                   InvokeInliningInfo &Invoke) {
+  for (BasicBlock::iterator BBI = BB->begin(), E = BB->end(); BBI != E; ) {
+    Instruction *I = BBI++;
+    
+    // We only need to check for function calls: inlined invoke
+    // instructions require no special handling.
+    CallInst *CI = dyn_cast<CallInst>(I);
+    if (CI == 0) continue;
+
+    // LIBUNWIND: merge selector instructions.
+    if (EHSelectorInst *Inner = dyn_cast<EHSelectorInst>(CI)) {
+      EHSelectorInst *Outer = findSelectorForLandingPad(Invoke.getUnwindDest());
+      if (!Outer) continue;
+
+      bool innerIsOnlyCleanup = isCleanupOnlySelector(Inner);
+      bool outerIsOnlyCleanup = isCleanupOnlySelector(Outer);
+
+      // If both selectors contain only cleanups, we don't need to do
+      // anything.  TODO: this is really just a very specific instance
+      // of a much more general optimization.
+      if (innerIsOnlyCleanup && outerIsOnlyCleanup) continue;
+
+      // Otherwise, we just append the outer selector to the inner selector.
+      SmallVector<Value*, 16> NewSelector;
+      for (unsigned i = 0, e = Inner->getNumArgOperands(); i != e; ++i)
+        NewSelector.push_back(Inner->getArgOperand(i));
+      for (unsigned i = 2, e = Outer->getNumArgOperands(); i != e; ++i)
+        NewSelector.push_back(Outer->getArgOperand(i));
+
+      CallInst *NewInner = CallInst::Create(Inner->getCalledValue(),
+                                            NewSelector.begin(),
+                                            NewSelector.end(),
+                                            "",
+                                            Inner);
+      // No need to copy attributes, calling convention, etc.
+      NewInner->takeName(Inner);
+      Inner->replaceAllUsesWith(NewInner);
+      Inner->eraseFromParent();
+      continue;
+    }
+    
+    // If this call cannot unwind, don't convert it to an invoke.
+    if (CI->doesNotThrow())
+      continue;
+    
+    // Convert this function call into an invoke instruction.
+    // First, split the basic block.
+    BasicBlock *Split = BB->splitBasicBlock(CI, CI->getName()+".noexc");
+
+    bool skipNextBlock = false;
+
+    // LIBUNWIND: If this is a call to @_Unwind_Resume, just branch
+    // directly to the new landing pad.
+    if (isUnwindResume(CI->getCalledValue())) {
+      BranchInst::Create(Invoke.getUnwindDest(), BB->getTerminator());
+
+      // TODO: 'Split' is now unreachable; clean it up.
+
+      // We want to leave the original call intact so that the call
+      // graph and other structures won't get misled.  We also have to
+      // avoid processing the next block, or we'll iterate here forever.
+      skipNextBlock = true;
+
+    // Otherwise, create the new invoke instruction.
+    } else {
+      ImmutableCallSite CS(CI);
+      SmallVector<Value*, 8> InvokeArgs(CS.arg_begin(), CS.arg_end());
+      InvokeInst *II =
+        InvokeInst::Create(CI->getCalledValue(), Split, Invoke.getUnwindDest(),
+                           InvokeArgs.begin(), InvokeArgs.end(),
+                           CI->getName(), BB->getTerminator());
+      II->setCallingConv(CI->getCallingConv());
+      II->setAttributes(CI->getAttributes());
+    
+      // Make sure that anything using the call now uses the invoke!  This also
+      // updates the CallGraph if present, because it uses a WeakVH.
+      CI->replaceAllUsesWith(II);
+
+      Split->getInstList().pop_front();  // Delete the original call
+    }
+    
+    // Delete the unconditional branch inserted by splitBasicBlock
+    BB->getInstList().pop_back();
+    
+    // Update any PHI nodes in the exceptional block to indicate that
+    // there is now a new entry in them.
+    Invoke.addIncomingPHIValuesFor(BB);
+    
+    // This basic block is now complete, the caller will continue scanning the
+    // next one.
+    return skipNextBlock;
+  }
+
+  return false;
+}
+  
+
 /// HandleInlinedInvoke - If we inlined an invoke site, we need to convert calls
 /// in the body of the inlined function into invokes and turn unwind
 /// instructions into branches to the invoke unwind dest.
 ///
-/// II is the invoke instruction begin inlined.  FirstNewBlock is the first
+/// II is the invoke instruction being inlined.  FirstNewBlock is the first
 /// block of the inlined code (the last block is the end of the function),
 /// and InlineCodeInfo is information about the code that got inlined.
 static void HandleInlinedInvoke(InvokeInst *II, BasicBlock *FirstNewBlock,
                                 ClonedCodeInfo &InlinedCodeInfo) {
   BasicBlock *InvokeDest = II->getUnwindDest();
-  std::vector<Value*> InvokeDestPHIValues;
-
-  // If there are PHI nodes in the unwind destination block, we need to
-  // keep track of which values came into them from this invoke, then remove
-  // the entry for this block.
-  BasicBlock *InvokeBlock = II->getParent();
-  for (BasicBlock::iterator I = InvokeDest->begin(); isa<PHINode>(I); ++I) {
-    PHINode *PN = cast<PHINode>(I);
-    // Save the value to use for this edge.
-    InvokeDestPHIValues.push_back(PN->getIncomingValueForBlock(InvokeBlock));
-  }
 
   Function *Caller = FirstNewBlock->getParent();
 
   // The inlined code is currently at the end of the function, scan from the
   // start of the inlined code to its end, checking for stuff we need to
-  // rewrite.
-  if (InlinedCodeInfo.ContainsCalls || InlinedCodeInfo.ContainsUnwinds) {
-    for (Function::iterator BB = FirstNewBlock, E = Caller->end();
-         BB != E; ++BB) {
-      if (InlinedCodeInfo.ContainsCalls) {
-        for (BasicBlock::iterator BBI = BB->begin(), E = BB->end(); BBI != E; ){
-          Instruction *I = BBI++;
-
-          // We only need to check for function calls: inlined invoke
-          // instructions require no special handling.
-          if (!isa<CallInst>(I)) continue;
-          CallInst *CI = cast<CallInst>(I);
-
-          // If this call cannot unwind, don't convert it to an invoke.
-          if (CI->doesNotThrow())
-            continue;
-
-          // Convert this function call into an invoke instruction.
-          // First, split the basic block.
-          BasicBlock *Split = BB->splitBasicBlock(CI, CI->getName()+".noexc");
-
-          // Next, create the new invoke instruction, inserting it at the end
-          // of the old basic block.
-          SmallVector<Value*, 8> InvokeArgs(CI->op_begin()+1, CI->op_end());
-          InvokeInst *II =
-            InvokeInst::Create(CI->getCalledValue(), Split, InvokeDest,
-                               InvokeArgs.begin(), InvokeArgs.end(),
-                               CI->getName(), BB->getTerminator());
-          II->setCallingConv(CI->getCallingConv());
-          II->setAttributes(CI->getAttributes());
-
-          // Make sure that anything using the call now uses the invoke!
-          CI->replaceAllUsesWith(II);
-
-          // Delete the unconditional branch inserted by splitBasicBlock
-          BB->getInstList().pop_back();
-          Split->getInstList().pop_front();  // Delete the original call
-
-          // Update any PHI nodes in the exceptional block to indicate that
-          // there is now a new entry in them.
-          unsigned i = 0;
-          for (BasicBlock::iterator I = InvokeDest->begin();
-               isa<PHINode>(I); ++I, ++i) {
-            PHINode *PN = cast<PHINode>(I);
-            PN->addIncoming(InvokeDestPHIValues[i], BB);
-          }
-
-          // This basic block is now complete, start scanning the next one.
-          break;
-        }
-      }
+  // rewrite.  If the code doesn't have calls or unwinds, we know there is
+  // nothing to rewrite.
+  if (!InlinedCodeInfo.ContainsCalls && !InlinedCodeInfo.ContainsUnwinds) {
+    // Now that everything is happy, we have one final detail.  The PHI nodes in
+    // the exception destination block still have entries due to the original
+    // invoke instruction.  Eliminate these entries (which might even delete the
+    // PHI node) now.
+    InvokeDest->removePredecessor(II->getParent());
+    return;
+  }
 
-      if (UnwindInst *UI = dyn_cast<UnwindInst>(BB->getTerminator())) {
-        // An UnwindInst requires special handling when it gets inlined into an
-        // invoke site.  Once this happens, we know that the unwind would cause
-        // a control transfer to the invoke exception destination, so we can
-        // transform it into a direct branch to the exception destination.
-        BranchInst::Create(InvokeDest, UI);
-
-        // Delete the unwind instruction!
-        UI->eraseFromParent();
-
-        // Update any PHI nodes in the exceptional block to indicate that
-        // there is now a new entry in them.
-        unsigned i = 0;
-        for (BasicBlock::iterator I = InvokeDest->begin();
-             isa<PHINode>(I); ++I, ++i) {
-          PHINode *PN = cast<PHINode>(I);
-          PN->addIncoming(InvokeDestPHIValues[i], BB);
-        }
+  InvokeInliningInfo Invoke(II);
+  
+  for (Function::iterator BB = FirstNewBlock, E = Caller->end(); BB != E; ++BB){
+    if (InlinedCodeInfo.ContainsCalls)
+      if (HandleCallsInBlockInlinedThroughInvoke(BB, Invoke)) {
+        // Honor a request to skip the next block.  We don't need to
+        // consider UnwindInsts in this case either.
+        ++BB;
+        continue;
       }
+
+    if (UnwindInst *UI = dyn_cast<UnwindInst>(BB->getTerminator())) {
+      // An UnwindInst requires special handling when it gets inlined into an
+      // invoke site.  Once this happens, we know that the unwind would cause
+      // a control transfer to the invoke exception destination, so we can
+      // transform it into a direct branch to the exception destination.
+      BranchInst::Create(InvokeDest, UI);
+
+      // Delete the unwind instruction!
+      UI->eraseFromParent();
+
+      // Update any PHI nodes in the exceptional block to indicate that
+      // there is now a new entry in them.
+      Invoke.addIncomingPHIValuesFor(BB);
     }
   }
 
@@ -146,33 +286,182 @@ static void HandleInlinedInvoke(InvokeInst *II, BasicBlock *FirstNewBlock,
 /// some edges of the callgraph may remain.
 static void UpdateCallGraphAfterInlining(CallSite CS,
                                          Function::iterator FirstNewBlock,
-                                       DenseMap<const Value*, Value*> &ValueMap,
-                                         CallGraph &CG) {
+                                         ValueToValueMapTy &VMap,
+                                         InlineFunctionInfo &IFI) {
+  CallGraph &CG = *IFI.CG;
   const Function *Caller = CS.getInstruction()->getParent()->getParent();
   const Function *Callee = CS.getCalledFunction();
-
-  // Update the call graph by deleting the edge from Callee to Caller
   CallGraphNode *CalleeNode = CG[Callee];
   CallGraphNode *CallerNode = CG[Caller];
-  CallerNode->removeCallEdgeFor(CS);
 
   // Since we inlined some uninlined call sites in the callee into the caller,
   // add edges from the caller to all of the callees of the callee.
-  for (CallGraphNode::iterator I = CalleeNode->begin(),
-       E = CalleeNode->end(); I != E; ++I) {
-    const Instruction *OrigCall = I->first.getInstruction();
+  CallGraphNode::iterator I = CalleeNode->begin(), E = CalleeNode->end();
+
+  // Consider the case where CalleeNode == CallerNode.
+  CallGraphNode::CalledFunctionsVector CallCache;
+  if (CalleeNode == CallerNode) {
+    CallCache.assign(I, E);
+    I = CallCache.begin();
+    E = CallCache.end();
+  }
+
+  for (; I != E; ++I) {
+    const Value *OrigCall = I->first;
 
-    DenseMap<const Value*, Value*>::iterator VMI = ValueMap.find(OrigCall);
+    ValueToValueMapTy::iterator VMI = VMap.find(OrigCall);
     // Only copy the edge if the call was inlined!
-    if (VMI != ValueMap.end() && VMI->second) {
-      // If the call was inlined, but then constant folded, there is no edge to
-      // add.  Check for this case.
-      if (Instruction *NewCall = dyn_cast<Instruction>(VMI->second))
-        CallerNode->addCalledFunction(CallSite::get(NewCall), I->second);
+    if (VMI == VMap.end() || VMI->second == 0)
+      continue;
+    
+    // If the call was inlined, but then constant folded, there is no edge to
+    // add.  Check for this case.
+    Instruction *NewCall = dyn_cast<Instruction>(VMI->second);
+    if (NewCall == 0) continue;
+
+    // Remember that this call site got inlined for the client of
+    // InlineFunction.
+    IFI.InlinedCalls.push_back(NewCall);
+
+    // It's possible that inlining the callsite will cause it to go from an
+    // indirect to a direct call by resolving a function pointer.  If this
+    // happens, set the callee of the new call site to a more precise
+    // destination.  This can also happen if the call graph node of the caller
+    // was just unnecessarily imprecise.
+    if (I->second->getFunction() == 0)
+      if (Function *F = CallSite(NewCall).getCalledFunction()) {
+        // Indirect call site resolved to direct call.
+        CallerNode->addCalledFunction(CallSite(NewCall), CG[F]);
+
+        continue;
+      }
+
+    CallerNode->addCalledFunction(CallSite(NewCall), I->second);
+  }
+  
+  // Update the call graph by deleting the edge from Callee to Caller.  We must
+  // do this after the loop above in case Caller and Callee are the same.
+  CallerNode->removeCallEdgeFor(CS);
+}
+
+/// HandleByValArgument - When inlining a call site that has a byval argument,
+/// we have to make the implicit memcpy explicit by adding it.
+static Value *HandleByValArgument(Value *Arg, Instruction *TheCall,
+                                  const Function *CalledFunc,
+                                  InlineFunctionInfo &IFI,
+                                  unsigned ByValAlignment) {
+  const Type *AggTy = cast<PointerType>(Arg->getType())->getElementType();
+
+  // If the called function is readonly, then it could not mutate the caller's
+  // copy of the byval'd memory.  In this case, it is safe to elide the copy and
+  // temporary.
+  if (CalledFunc->onlyReadsMemory()) {
+    // If the byval argument has a specified alignment that is greater than the
+    // passed in pointer, then we either have to round up the input pointer or
+    // give up on this transformation.
+    if (ByValAlignment <= 1)  // 0 = unspecified, 1 = no particular alignment.
+      return Arg;
+
+    // If the pointer is already known to be sufficiently aligned, or if we can
+    // round it up to a larger alignment, then we don't need a temporary.
+    if (getOrEnforceKnownAlignment(Arg, ByValAlignment,
+                                   IFI.TD) >= ByValAlignment)
+      return Arg;
+    
+    // Otherwise, we have to make a memcpy to get a safe alignment.  This is bad
+    // for code quality, but rarely happens and is required for correctness.
+  }
+  
+  LLVMContext &Context = Arg->getContext();
+
+  const Type *VoidPtrTy = Type::getInt8PtrTy(Context);
+  
+  // Create the alloca.  If we have TargetData, use nice alignment.
+  unsigned Align = 1;
+  if (IFI.TD)
+    Align = IFI.TD->getPrefTypeAlignment(AggTy);
+  
+  // If the byval had an alignment specified, we *must* use at least that
+  // alignment, as it is required by the byval argument (and uses of the
+  // pointer inside the callee).
+  Align = std::max(Align, ByValAlignment);
+  
+  Function *Caller = TheCall->getParent()->getParent(); 
+  
+  Value *NewAlloca = new AllocaInst(AggTy, 0, Align, Arg->getName(), 
+                                    &*Caller->begin()->begin());
+  // Emit a memcpy.
+  const Type *Tys[3] = {VoidPtrTy, VoidPtrTy, Type::getInt64Ty(Context)};
+  Function *MemCpyFn = Intrinsic::getDeclaration(Caller->getParent(),
+                                                 Intrinsic::memcpy, 
+                                                 Tys, 3);
+  Value *DestCast = new BitCastInst(NewAlloca, VoidPtrTy, "tmp", TheCall);
+  Value *SrcCast = new BitCastInst(Arg, VoidPtrTy, "tmp", TheCall);
+  
+  Value *Size;
+  if (IFI.TD == 0)
+    Size = ConstantExpr::getSizeOf(AggTy);
+  else
+    Size = ConstantInt::get(Type::getInt64Ty(Context),
+                            IFI.TD->getTypeStoreSize(AggTy));
+  
+  // Always generate a memcpy of alignment 1 here because we don't know
+  // the alignment of the src pointer.  Other optimizations can infer
+  // better alignment.
+  Value *CallArgs[] = {
+    DestCast, SrcCast, Size,
+    ConstantInt::get(Type::getInt32Ty(Context), 1),
+    ConstantInt::getFalse(Context) // isVolatile
+  };
+  CallInst *TheMemCpy =
+    CallInst::Create(MemCpyFn, CallArgs, CallArgs+5, "", TheCall);
+  
+  // If we have a call graph, update it.
+  if (CallGraph *CG = IFI.CG) {
+    CallGraphNode *MemCpyCGN = CG->getOrInsertFunction(MemCpyFn);
+    CallGraphNode *CallerNode = (*CG)[Caller];
+    CallerNode->addCalledFunction(TheMemCpy, MemCpyCGN);
+  }
+  
+  // Uses of the argument in the function should use our new alloca
+  // instead.
+  return NewAlloca;
+}
+
+// isUsedByLifetimeMarker - Check whether this Value is used by a lifetime
+// intrinsic.
+static bool isUsedByLifetimeMarker(Value *V) {
+  for (Value::use_iterator UI = V->use_begin(), UE = V->use_end(); UI != UE;
+       ++UI) {
+    if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(*UI)) {
+      switch (II->getIntrinsicID()) {
+      default: break;
+      case Intrinsic::lifetime_start:
+      case Intrinsic::lifetime_end:
+        return true;
+      }
     }
   }
+  return false;
 }
 
+// hasLifetimeMarkers - Check whether the given alloca already has
+// lifetime.start or lifetime.end intrinsics.
+static bool hasLifetimeMarkers(AllocaInst *AI) {
+  const Type *Int8PtrTy = Type::getInt8PtrTy(AI->getType()->getContext());
+  if (AI->getType() == Int8PtrTy)
+    return isUsedByLifetimeMarker(AI);
+
+  // Do a scan to find all the bitcasts to i8*.
+  for (Value::use_iterator I = AI->use_begin(), E = AI->use_end(); I != E;
+       ++I) {
+    if (I->getType() != Int8PtrTy) continue;
+    if (!isa<BitCastInst>(*I)) continue;
+    if (isUsedByLifetimeMarker(*I))
+      return true;
+  }
+  return false;
+}
 
 // InlineFunction - This function inlines the called function into the basic
 // block of the caller.  This returns false if it is not possible to inline this
@@ -180,24 +469,27 @@ static void UpdateCallGraphAfterInlining(CallSite CS,
 //
 // Note that this only does one level of inlining.  For example, if the
 // instruction 'call B' is inlined, and 'B' calls 'C', then the call to 'C' now
-// exists in the instruction stream.  Similiarly this will inline a recursive
+// exists in the instruction stream.  Similarly this will inline a recursive
 // function by one level.
 //
-bool llvm::InlineFunction(CallSite CS, CallGraph *CG, const TargetData *TD) {
+bool llvm::InlineFunction(CallSite CS, InlineFunctionInfo &IFI) {
   Instruction *TheCall = CS.getInstruction();
+  LLVMContext &Context = TheCall->getContext();
   assert(TheCall->getParent() && TheCall->getParent()->getParent() &&
          "Instruction not in function!");
 
+  // If IFI has any state in it, zap it before we fill it in.
+  IFI.reset();
+  
   const Function *CalledFunc = CS.getCalledFunction();
   if (CalledFunc == 0 ||          // Can't inline external function or indirect
       CalledFunc->isDeclaration() || // call, or call to a vararg function!
       CalledFunc->getFunctionType()->isVarArg()) return false;
 
-
-  // If the call to the callee is a non-tail call, we must clear the 'tail'
+  // If the call to the callee is not a tail call, we must clear the 'tail'
   // flags on any calls that we inline.
   bool MustClearTailCallFlags =
-    isa<CallInst>(TheCall) && !cast<CallInst>(TheCall)->isTailCall();
+    !(isa<CallInst>(TheCall) && cast<CallInst>(TheCall)->isTailCall());
 
   // If the call to the callee cannot throw, set the 'nounwind' flag on any
   // calls that we inline.
@@ -224,12 +516,12 @@ bool llvm::InlineFunction(CallSite CS, CallGraph *CG, const TargetData *TD) {
 
   // Make sure to capture all of the return instructions from the cloned
   // function.
-  std::vector<ReturnInst*> Returns;
+  SmallVector<ReturnInst*, 8> Returns;
   ClonedCodeInfo InlinedFunctionInfo;
   Function::iterator FirstNewBlock;
 
-  { // Scope to destroy ValueMap after cloning.
-    DenseMap<const Value*, Value*> ValueMap;
+  { // Scope to destroy VMap after cloning.
+    ValueToValueMapTy VMap;
 
     assert(CalledFunc->arg_size() == CS.arg_size() &&
            "No varargs calls can be inlined!");
@@ -246,65 +538,33 @@ bool llvm::InlineFunction(CallSite CS, CallGraph *CG, const TargetData *TD) {
       // by them explicit.  However, we don't do this if the callee is readonly
       // or readnone, because the copy would be unneeded: the callee doesn't
       // modify the struct.
-      if (CalledFunc->paramHasAttr(ArgNo+1, Attribute::ByVal) &&
-          !CalledFunc->onlyReadsMemory()) {
-        const Type *AggTy = cast<PointerType>(I->getType())->getElementType();
-        const Type *VoidPtrTy = PointerType::getUnqual(Type::Int8Ty);
-
-        // Create the alloca.  If we have TargetData, use nice alignment.
-        unsigned Align = 1;
-        if (TD) Align = TD->getPrefTypeAlignment(AggTy);
-        Value *NewAlloca = new AllocaInst(AggTy, 0, Align, I->getName(),
-                                          Caller->begin()->begin());
-        // Emit a memcpy.
-        Function *MemCpyFn = Intrinsic::getDeclaration(Caller->getParent(),
-                                                       Intrinsic::memcpy_i64);
-        Value *DestCast = new BitCastInst(NewAlloca, VoidPtrTy, "tmp", TheCall);
-        Value *SrcCast = new BitCastInst(*AI, VoidPtrTy, "tmp", TheCall);
-
-        Value *Size;
-        if (TD == 0)
-          Size = ConstantExpr::getSizeOf(AggTy);
-        else
-          Size = ConstantInt::get(Type::Int64Ty, TD->getTypeStoreSize(AggTy));
-
-        // Always generate a memcpy of alignment 1 here because we don't know
-        // the alignment of the src pointer.  Other optimizations can infer
-        // better alignment.
-        Value *CallArgs[] = {
-          DestCast, SrcCast, Size, ConstantInt::get(Type::Int32Ty, 1)
-        };
-        CallInst *TheMemCpy =
-          CallInst::Create(MemCpyFn, CallArgs, CallArgs+4, "", TheCall);
-
-        // If we have a call graph, update it.
-        if (CG) {
-          CallGraphNode *MemCpyCGN = CG->getOrInsertFunction(MemCpyFn);
-          CallGraphNode *CallerNode = (*CG)[Caller];
-          CallerNode->addCalledFunction(TheMemCpy, MemCpyCGN);
-        }
-
-        // Uses of the argument in the function should use our new alloca
-        // instead.
-        ActualArg = NewAlloca;
+      if (CalledFunc->paramHasAttr(ArgNo+1, Attribute::ByVal)) {
+        ActualArg = HandleByValArgument(ActualArg, TheCall, CalledFunc, IFI,
+                                        CalledFunc->getParamAlignment(ArgNo+1));
+ 
+        // Calls that we inline may use the new alloca, so we need to clear
+        // their 'tail' flags if HandleByValArgument introduced a new alloca and
+        // the callee has calls.
+        MustClearTailCallFlags |= ActualArg != *AI;
       }
 
-      ValueMap[I] = ActualArg;
+      VMap[I] = ActualArg;
     }
 
     // We want the inliner to prune the code as it copies.  We would LOVE to
     // have no dead or constant instructions leftover after inlining occurs
     // (which can happen, e.g., because an argument was constant), but we'll be
     // happy with whatever the cloner can do.
-    CloneAndPruneFunctionInto(Caller, CalledFunc, ValueMap, Returns, ".i",
-                              &InlinedFunctionInfo, TD);
+    CloneAndPruneFunctionInto(Caller, CalledFunc, VMap, 
+                              /*ModuleLevelChanges=*/false, Returns, ".i",
+                              &InlinedFunctionInfo, IFI.TD, TheCall);
 
     // Remember the first block that is newly cloned over.
     FirstNewBlock = LastBlock; ++FirstNewBlock;
 
     // Update the callgraph if requested.
-    if (CG)
-      UpdateCallGraphAfterInlining(CS, FirstNewBlock, ValueMap, *CG);
+    if (IFI.CG)
+      UpdateCallGraphAfterInlining(CS, FirstNewBlock, VMap, IFI);
   }
 
   // If there are any alloca instructions in the block that used to be the entry
@@ -315,31 +575,72 @@ bool llvm::InlineFunction(CallSite CS, CallGraph *CG, const TargetData *TD) {
   {
     BasicBlock::iterator InsertPoint = Caller->begin()->begin();
     for (BasicBlock::iterator I = FirstNewBlock->begin(),
-           E = FirstNewBlock->end(); I != E; )
-      if (AllocaInst *AI = dyn_cast<AllocaInst>(I++)) {
-        // If the alloca is now dead, remove it.  This often occurs due to code
-        // specialization.
-        if (AI->use_empty()) {
-          AI->eraseFromParent();
-          continue;
-        }
+         E = FirstNewBlock->end(); I != E; ) {
+      AllocaInst *AI = dyn_cast<AllocaInst>(I++);
+      if (AI == 0) continue;
+      
+      // If the alloca is now dead, remove it.  This often occurs due to code
+      // specialization.
+      if (AI->use_empty()) {
+        AI->eraseFromParent();
+        continue;
+      }
 
-        if (isa<Constant>(AI->getArraySize())) {
-          // Scan for the block of allocas that we can move over, and move them
-          // all at once.
-          while (isa<AllocaInst>(I) &&
-                 isa<Constant>(cast<AllocaInst>(I)->getArraySize()))
-            ++I;
-
-          // Transfer all of the allocas over in a block.  Using splice means
-          // that the instructions aren't removed from the symbol table, then
-          // reinserted.
-          Caller->getEntryBlock().getInstList().splice(
-              InsertPoint,
-              FirstNewBlock->getInstList(),
-              AI, I);
-        }
+      if (!isa<Constant>(AI->getArraySize()))
+        continue;
+      
+      // Keep track of the static allocas that we inline into the caller.
+      IFI.StaticAllocas.push_back(AI);
+      
+      // Scan for the block of allocas that we can move over, and move them
+      // all at once.
+      while (isa<AllocaInst>(I) &&
+             isa<Constant>(cast<AllocaInst>(I)->getArraySize())) {
+        IFI.StaticAllocas.push_back(cast<AllocaInst>(I));
+        ++I;
       }
+
+      // Transfer all of the allocas over in a block.  Using splice means
+      // that the instructions aren't removed from the symbol table, then
+      // reinserted.
+      Caller->getEntryBlock().getInstList().splice(InsertPoint,
+                                                   FirstNewBlock->getInstList(),
+                                                   AI, I);
+    }
+  }
+
+  // Leave lifetime markers for the static alloca's, scoping them to the
+  // function we just inlined.
+  if (!IFI.StaticAllocas.empty()) {
+    // Also preserve the call graph, if applicable.
+    CallGraphNode *StartCGN = 0, *EndCGN = 0, *CallerNode = 0;
+    if (CallGraph *CG = IFI.CG) {
+      Function *Start = Intrinsic::getDeclaration(Caller->getParent(),
+                                                  Intrinsic::lifetime_start);
+      Function *End = Intrinsic::getDeclaration(Caller->getParent(),
+                                                Intrinsic::lifetime_end);
+      StartCGN = CG->getOrInsertFunction(Start);
+      EndCGN = CG->getOrInsertFunction(End);
+      CallerNode = (*CG)[Caller];
+    }
+
+    IRBuilder<> builder(FirstNewBlock->begin());
+    for (unsigned ai = 0, ae = IFI.StaticAllocas.size(); ai != ae; ++ai) {
+      AllocaInst *AI = IFI.StaticAllocas[ai];
+
+      // If the alloca is already scoped to something smaller than the whole
+      // function then there's no need to add redundant, less accurate markers.
+      if (hasLifetimeMarkers(AI))
+        continue;
+
+      CallInst *StartCall = builder.CreateLifetimeStart(AI);
+      if (IFI.CG) CallerNode->addCalledFunction(StartCall, StartCGN);
+      for (unsigned ri = 0, re = Returns.size(); ri != re; ++ri) {
+        IRBuilder<> builder(Returns[ri]);
+        CallInst *EndCall = builder.CreateLifetimeEnd(AI);
+        if (IFI.CG) CallerNode->addCalledFunction(EndCall, EndCGN);
+      }
+    }
   }
 
   // If the inlined code contained dynamic alloca instructions, wrap the inlined
@@ -347,31 +648,28 @@ bool llvm::InlineFunction(CallSite CS, CallGraph *CG, const TargetData *TD) {
   if (InlinedFunctionInfo.ContainsDynamicAllocas) {
     Module *M = Caller->getParent();
     // Get the two intrinsics we care about.
-    Constant *StackSave, *StackRestore;
-    StackSave    = Intrinsic::getDeclaration(M, Intrinsic::stacksave);
-    StackRestore = Intrinsic::getDeclaration(M, Intrinsic::stackrestore);
+    Function *StackSave = Intrinsic::getDeclaration(M, Intrinsic::stacksave);
+    Function *StackRestore=Intrinsic::getDeclaration(M,Intrinsic::stackrestore);
 
     // If we are preserving the callgraph, add edges to the stacksave/restore
     // functions for the calls we insert.
     CallGraphNode *StackSaveCGN = 0, *StackRestoreCGN = 0, *CallerNode = 0;
-    if (CG) {
-      // We know that StackSave/StackRestore are Function*'s, because they are
-      // intrinsics which must have the right types.
-      StackSaveCGN    = CG->getOrInsertFunction(cast<Function>(StackSave));
-      StackRestoreCGN = CG->getOrInsertFunction(cast<Function>(StackRestore));
+    if (CallGraph *CG = IFI.CG) {
+      StackSaveCGN    = CG->getOrInsertFunction(StackSave);
+      StackRestoreCGN = CG->getOrInsertFunction(StackRestore);
       CallerNode = (*CG)[Caller];
     }
 
     // Insert the llvm.stacksave.
     CallInst *SavedPtr = CallInst::Create(StackSave, "savedstack",
                                           FirstNewBlock->begin());
-    if (CG) CallerNode->addCalledFunction(SavedPtr, StackSaveCGN);
+    if (IFI.CG) CallerNode->addCalledFunction(SavedPtr, StackSaveCGN);
 
     // Insert a call to llvm.stackrestore before any return instructions in the
     // inlined function.
     for (unsigned i = 0, e = Returns.size(); i != e; ++i) {
       CallInst *CI = CallInst::Create(StackRestore, SavedPtr, "", Returns[i]);
-      if (CG) CallerNode->addCalledFunction(CI, StackRestoreCGN);
+      if (IFI.CG) CallerNode->addCalledFunction(CI, StackRestoreCGN);
     }
 
     // Count the number of StackRestore calls we insert.
@@ -383,7 +681,8 @@ bool llvm::InlineFunction(CallSite CS, CallGraph *CG, const TargetData *TD) {
       for (Function::iterator BB = FirstNewBlock, E = Caller->end();
            BB != E; ++BB)
         if (UnwindInst *UI = dyn_cast<UnwindInst>(BB->getTerminator())) {
-          CallInst::Create(StackRestore, SavedPtr, "", UI);
+          CallInst *CI = CallInst::Create(StackRestore, SavedPtr, "", UI);
+          if (IFI.CG) CallerNode->addCalledFunction(CI, StackRestoreCGN);
           ++NumStackRestores;
         }
     }
@@ -413,7 +712,7 @@ bool llvm::InlineFunction(CallSite CS, CallGraph *CG, const TargetData *TD) {
          BB != E; ++BB) {
       TerminatorInst *Term = BB->getTerminator();
       if (isa<UnwindInst>(Term)) {
-        new UnreachableInst(Term);
+        new UnreachableInst(Context, Term);
         BB->getInstList().erase(Term);
       }
     }
@@ -443,7 +742,10 @@ bool llvm::InlineFunction(CallSite CS, CallGraph *CG, const TargetData *TD) {
     // uses of the returned value.
     if (!TheCall->use_empty()) {
       ReturnInst *R = Returns[0];
-      TheCall->replaceAllUsesWith(R->getReturnValue());
+      if (TheCall == R->getReturnValue())
+        TheCall->replaceAllUsesWith(UndefValue::get(TheCall->getType()));
+      else
+        TheCall->replaceAllUsesWith(R->getReturnValue());
     }
     // Since we are now done with the Call/Invoke, we can delete it.
     TheCall->eraseFromParent();
@@ -500,20 +802,20 @@ bool llvm::InlineFunction(CallSite CS, CallGraph *CG, const TargetData *TD) {
   // any users of the original call/invoke instruction.
   const Type *RTy = CalledFunc->getReturnType();
 
+  PHINode *PHI = 0;
   if (Returns.size() > 1) {
     // The PHI node should go at the front of the new basic block to merge all
     // possible incoming values.
-    PHINode *PHI = 0;
     if (!TheCall->use_empty()) {
-      PHI = PHINode::Create(RTy, TheCall->getName(),
+      PHI = PHINode::Create(RTy, Returns.size(), TheCall->getName(),
                             AfterCallBB->begin());
       // Anything that used the result of the function call should now use the
       // PHI node as their operand.
       TheCall->replaceAllUsesWith(PHI);
     }
 
-    // Loop over all of the return instructions adding entries to the PHI node as
-    // appropriate.
+    // Loop over all of the return instructions adding entries to the PHI node
+    // as appropriate.
     if (PHI) {
       for (unsigned i = 0, e = Returns.size(); i != e; ++i) {
         ReturnInst *RI = Returns[i];
@@ -523,7 +825,8 @@ bool llvm::InlineFunction(CallSite CS, CallGraph *CG, const TargetData *TD) {
       }
     }
 
-    // Add a branch to the merge points and remove retrun instructions.
+
+    // Add a branch to the merge points and remove return instructions.
     for (unsigned i = 0, e = Returns.size(); i != e; ++i) {
       ReturnInst *RI = Returns[i];
       BranchInst::Create(AfterCallBB, RI);
@@ -532,8 +835,12 @@ bool llvm::InlineFunction(CallSite CS, CallGraph *CG, const TargetData *TD) {
   } else if (!Returns.empty()) {
     // Otherwise, if there is exactly one return value, just replace anything
     // using the return value of the call with the computed value.
-    if (!TheCall->use_empty())
-      TheCall->replaceAllUsesWith(Returns[0]->getReturnValue());
+    if (!TheCall->use_empty()) {
+      if (TheCall == Returns[0]->getReturnValue())
+        TheCall->replaceAllUsesWith(UndefValue::get(TheCall->getType()));
+      else
+        TheCall->replaceAllUsesWith(Returns[0]->getReturnValue());
+    }
 
     // Splice the code from the return block into the block that it will return
     // to, which contains the code that was after the call.
@@ -572,5 +879,14 @@ bool llvm::InlineFunction(CallSite CS, CallGraph *CG, const TargetData *TD) {
   // Now we can remove the CalleeEntry block, which is now empty.
   Caller->getBasicBlockList().erase(CalleeEntry);
 
+  // If we inserted a phi node, check to see if it has a single value (e.g. all
+  // the entries are the same or undef).  If so, remove the PHI so it doesn't
+  // block other optimizations.
+  if (PHI)
+    if (Value *V = SimplifyInstruction(PHI, IFI.TD)) {
+      PHI->replaceAllUsesWith(V);
+      PHI->eraseFromParent();
+    }
+
   return true;
 }