8 files changed, 32 insertions, 15 deletions
diff --git a/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp b/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp
index ea24d526942..36e7833ac16 100644
--- a/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp
+++ b/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp
@@ -155,7 +155,8 @@ CallGraphNode *ArgPromotion::PromoteArguments(CallGraphNode *CGN) {
     Type *AgTy = cast<PointerType>(PtrArg->getType())->getElementType();
 
     // If this is a byval argument, and if the aggregate type is small, just
-    // pass the elements, which is always safe.
+    // pass the elements, which is always safe.  This does not apply to
+    // inalloca.
     if (PtrArg->hasByValAttr()) {
       if (StructType *STy = dyn_cast<StructType>(AgTy)) {
         if (maxElements > 0 && STy->getNumElements() > maxElements) {
@@ -201,7 +202,7 @@ CallGraphNode *ArgPromotion::PromoteArguments(CallGraphNode *CGN) {
     }
     
     // Otherwise, see if we can promote the pointer to its value.
-    if (isSafeToPromoteArgument(PtrArg, PtrArg->hasByValAttr()))
+    if (isSafeToPromoteArgument(PtrArg, PtrArg->hasByValOrInAllocaAttr()))
       ArgsToPromote.insert(PtrArg);
   }
 
@@ -301,7 +302,8 @@ static void MarkIndicesSafe(const ArgPromotion::IndicesVector &ToMark,
 /// This method limits promotion of aggregates to only promote up to three
 /// elements of the aggregate in order to avoid exploding the number of
 /// arguments passed in.
-bool ArgPromotion::isSafeToPromoteArgument(Argument *Arg, bool isByVal) const {
+bool ArgPromotion::isSafeToPromoteArgument(Argument *Arg,
+                                           bool isByValOrInAlloca) const {
   typedef std::set<IndicesVector> GEPIndicesSet;
 
   // Quick exit for unused arguments
@@ -323,6 +325,9 @@ bool ArgPromotion::isSafeToPromoteArgument(Argument *Arg, bool isByVal) const {
   //
   // This set will contain all sets of indices that are loaded in the entry
   // block, and thus are safe to unconditionally load in the caller.
+  //
+  // This optimization is also safe for InAlloca parameters, because it verifies
+  // that the address isn't captured.
   GEPIndicesSet SafeToUnconditionallyLoad;
 
   // This set contains all the sets of indices that we are planning to promote.
@@ -330,7 +335,7 @@ bool ArgPromotion::isSafeToPromoteArgument(Argument *Arg, bool isByVal) const {
   GEPIndicesSet ToPromote;
 
   // If the pointer is always valid, any load with first index 0 is valid.
-  if (isByVal || AllCallersPassInValidPointerForArgument(Arg))
+  if (isByValOrInAlloca || AllCallersPassInValidPointerForArgument(Arg))
     SafeToUnconditionallyLoad.insert(IndicesVector(1, 0));
 
   // First, iterate the entry block and mark loads of (geps of) arguments as
@@ -389,7 +394,7 @@ bool ArgPromotion::isSafeToPromoteArgument(Argument *Arg, bool isByVal) const {
         // TODO: This runs the above loop over and over again for dead GEPs
         // Couldn't we just do increment the UI iterator earlier and erase the
         // use?
-        return isSafeToPromoteArgument(Arg, isByVal);
+        return isSafeToPromoteArgument(Arg, isByValOrInAlloca);
       }
 
       // Ensure that all of the indices are constants.
diff --git a/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp b/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp
index 911c14e7e31..81dbd329c4b 100644
--- a/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp
+++ b/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp
@@ -378,7 +378,7 @@ bool DAE::RemoveDeadArgumentsFromCallers(Function &Fn)
        I != E; ++I) {
     Argument *Arg = I;
 
-    if (Arg->use_empty() && !Arg->hasByValAttr())
+    if (Arg->use_empty() && !Arg->hasByValOrInAllocaAttr())
       UnusedArgs.push_back(Arg->getArgNo());
   }
 
diff --git a/llvm/lib/Transforms/IPO/FunctionAttrs.cpp b/llvm/lib/Transforms/IPO/FunctionAttrs.cpp
index ea664506da2..92d2f79fa73 100644
--- a/llvm/lib/Transforms/IPO/FunctionAttrs.cpp
+++ b/llvm/lib/Transforms/IPO/FunctionAttrs.cpp
@@ -414,6 +414,10 @@ determinePointerReadAttrs(Argument *A,
   SmallSet<Use*, 32> Visited;
   int Count = 0;
 
+  // inalloca arguments are always clobbered by the call.
+  if (A->hasInAllocaAttr())
+    return Attribute::None;
+
   bool IsRead = false;
   // We don't need to track IsWritten. If A is written to, return immediately.
 
diff --git a/llvm/lib/Transforms/IPO/IPConstantPropagation.cpp b/llvm/lib/Transforms/IPO/IPConstantPropagation.cpp
index 8b816e556e3..16596bbfe98 100644
--- a/llvm/lib/Transforms/IPO/IPConstantPropagation.cpp
+++ b/llvm/lib/Transforms/IPO/IPConstantPropagation.cpp
@@ -135,7 +135,7 @@ bool IPCP::PropagateConstantsIntoArguments(Function &F) {
   for (unsigned i = 0, e = ArgumentConstants.size(); i != e; ++i, ++AI) {
     // Do we have a constant argument?
     if (ArgumentConstants[i].second || AI->use_empty() ||
-        (AI->hasByValAttr() && !F.onlyReadsMemory()))
+        AI->hasInAllocaAttr() || (AI->hasByValAttr() && !F.onlyReadsMemory()))
       continue;
   
     Value *V = ArgumentConstants[i].first;
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
index 7d2fc0a5289..8e308ecacf3 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -767,10 +767,10 @@ static bool isSafeToEliminateVarargsCast(const CallSite CS,
   if (!CI->isLosslessCast())
     return false;
 
-  // The size of ByVal arguments is derived from the type, so we
+  // The size of ByVal or InAlloca arguments is derived from the type, so we
   // can't change to a type with a different size.  If the size were
   // passed explicitly we could avoid this check.
-  if (!CS.isByValArgument(ix))
+  if (!CS.isByValOrInAllocaArgument(ix))
     return true;
 
   Type* SrcTy =
@@ -1049,6 +1049,9 @@ bool InstCombiner::transformConstExprCastCall(CallSite CS) {
                         typeIncompatible(ParamTy, i + 1), i + 1))
       return false;   // Attribute not compatible with transformed value.
 
+    if (CS.isInAllocaArgument(i))
+      return false;   // Cannot transform to and from inalloca.
+
     // If the parameter is passed as a byval argument, then we have to have a
     // sized type and the sized type has to have the same size as the old type.
     if (ParamTy != ActTy &&
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp b/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
index 4c861b3fd09..1f691768177 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
@@ -81,10 +81,14 @@ isOnlyCopiedFromConstantGlobal(Value *V, MemTransferInst *&TheCopy,
       if (CS.isCallee(UI))
         continue;
 
+      // Inalloca arguments are clobbered by the call.
+      unsigned ArgNo = CS.getArgumentNo(UI);
+      if (CS.isInAllocaArgument(ArgNo))
+        return false;
+
       // If this is a readonly/readnone call site, then we know it is just a
       // load (but one that potentially returns the value itself), so we can
       // ignore it if we know that the value isn't captured.
-      unsigned ArgNo = CS.getArgumentNo(UI);
       if (CS.onlyReadsMemory() &&
           (CS.getInstruction()->use_empty() || CS.doesNotCapture(ArgNo)))
         continue;
diff --git a/llvm/lib/Transforms/ObjCARC/ObjCARC.h b/llvm/lib/Transforms/ObjCARC/ObjCARC.h
index 8044494f18e..8a6d67ef828 100644
--- a/llvm/lib/Transforms/ObjCARC/ObjCARC.h
+++ b/llvm/lib/Transforms/ObjCARC/ObjCARC.h
@@ -308,6 +308,7 @@ static inline bool IsPotentialRetainableObjPtr(const Value *Op) {
   // Special arguments can not be a valid retainable object pointer.
   if (const Argument *Arg = dyn_cast<Argument>(Op))
     if (Arg->hasByValAttr() ||
+        Arg->hasInAllocaAttr() ||
         Arg->hasNestAttr() ||
         Arg->hasStructRetAttr())
       return false;
diff --git a/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp b/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
index 49f19bc60f2..453dca303d3 100644
--- a/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
+++ b/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
@@ -374,8 +374,8 @@ static OverwriteResult isOverwrite(const AliasAnalysis::Location &Later,
     return OverwriteUnknown;
 
   // Check to see if the later store is to the entire object (either a global,
-  // an alloca, or a byval argument).  If so, then it clearly overwrites any
-  // other store to the same object.
+  // an alloca, or a byval/inalloca argument).  If so, then it clearly
+  // overwrites any other store to the same object.
   const DataLayout *TD = AA.getDataLayout();
 
   const Value *UO1 = GetUnderlyingObject(P1, TD),
@@ -742,11 +742,11 @@ bool DSE::handleEndBlock(BasicBlock &BB) {
       DeadStackObjects.insert(I);
   }
 
-  // Treat byval arguments the same, stores to them are dead at the end of the
-  // function.
+  // Treat byval or inalloca arguments the same, stores to them are dead at the
+  // end of the function.
   for (Function::arg_iterator AI = BB.getParent()->arg_begin(),
        AE = BB.getParent()->arg_end(); AI != AE; ++AI)
-    if (AI->hasByValAttr())
+    if (AI->hasByValOrInAllocaAttr())
       DeadStackObjects.insert(AI);
 
   // Scan the basic block backwards