3 files changed, 35 insertions, 7 deletions
diff --git a/llvm/lib/CodeGen/MIRParser/MIRParser.cpp b/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
index 74d308de8bd..14cf47f8c0d 100644
--- a/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
+++ b/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
@@ -620,8 +620,8 @@ bool MIRParserImpl::initializeFrameInfo(PerFunctionMIParsingState &PFS,
                                         Object.IsImmutable, Object.IsAliased);
     else
       ObjectIdx = MFI.CreateFixedSpillStackObject(Object.Size, Object.Offset);
-    MFI.setObjectAlignment(ObjectIdx, Object.Alignment);
     MFI.setStackID(ObjectIdx, Object.StackID);
+    MFI.setObjectAlignment(ObjectIdx, Object.Alignment);
     if (!PFS.FixedStackObjectSlots.insert(std::make_pair(Object.ID.Value,
                                                          ObjectIdx))
              .second)
@@ -654,9 +654,9 @@ bool MIRParserImpl::initializeFrameInfo(PerFunctionMIParsingState &PFS,
     else
       ObjectIdx = MFI.CreateStackObject(
           Object.Size, Object.Alignment,
-          Object.Type == yaml::MachineStackObject::SpillSlot, Alloca);
+          Object.Type == yaml::MachineStackObject::SpillSlot, Alloca,
+          Object.StackID);
     MFI.setObjectOffset(ObjectIdx, Object.Offset);
-    MFI.setStackID(ObjectIdx, Object.StackID);
 
     if (!PFS.StackObjectSlots.insert(std::make_pair(Object.ID.Value, ObjectIdx))
              .second)
diff --git a/llvm/lib/CodeGen/MachineFrameInfo.cpp b/llvm/lib/CodeGen/MachineFrameInfo.cpp
index d75ba83ffd0..e8a3dda8cbd 100644
--- a/llvm/lib/CodeGen/MachineFrameInfo.cpp
+++ b/llvm/lib/CodeGen/MachineFrameInfo.cpp
@@ -56,7 +56,8 @@ int MachineFrameInfo::CreateStackObject(uint64_t Size, unsigned Alignment,
                                 !IsSpillSlot, StackID));
   int Index = (int)Objects.size() - NumFixedObjects - 1;
   assert(Index >= 0 && "Bad frame index!");
-  ensureMaxAlignment(Alignment);
+  if (StackID == 0)
+    ensureMaxAlignment(Alignment);
   return Index;
 }
 
@@ -141,11 +142,15 @@ unsigned MachineFrameInfo::estimateStackSize(const MachineFunction &MF) const {
   // should keep in mind that there's tight coupling between the two.
 
   for (int i = getObjectIndexBegin(); i != 0; ++i) {
+    // Only estimate stack size of default stack.
+    if (getStackID(i))
+      continue;
     int FixedOff = -getObjectOffset(i);
     if (FixedOff > Offset) Offset = FixedOff;
   }
   for (unsigned i = 0, e = getObjectIndexEnd(); i != e; ++i) {
-    if (isDeadObjectIndex(i))
+    // Only estimate stack size of live objects on default stack.
+    if (isDeadObjectIndex(i) || getStackID(i))
       continue;
     Offset += getObjectSize(i);
     unsigned Align = getObjectAlignment(i);
diff --git a/llvm/lib/CodeGen/PrologEpilogInserter.cpp b/llvm/lib/CodeGen/PrologEpilogInserter.cpp
index 920a915552a..67834c8c352 100644
--- a/llvm/lib/CodeGen/PrologEpilogInserter.cpp
+++ b/llvm/lib/CodeGen/PrologEpilogInserter.cpp
@@ -661,10 +661,13 @@ computeFreeStackSlots(MachineFrameInfo &MFI, bool StackGrowsDown,
   SmallVector<int, 16> AllocatedFrameSlots;
   // Add fixed objects.
   for (int i = MFI.getObjectIndexBegin(); i != 0; ++i)
-    AllocatedFrameSlots.push_back(i);
+    // StackSlot scavenging is only implemented for the default stack.
+    if (MFI.getStackID(i) == 0)
+      AllocatedFrameSlots.push_back(i);
   // Add callee-save objects.
   for (int i = MinCSFrameIndex; i <= (int)MaxCSFrameIndex; ++i)
-    AllocatedFrameSlots.push_back(i);
+    if (MFI.getStackID(i) == 0)
+      AllocatedFrameSlots.push_back(i);
 
   for (int i : AllocatedFrameSlots) {
     // These are converted from int64_t, but they should always fit in int
@@ -786,11 +789,21 @@ void PEI::calculateFrameObjectOffsets(MachineFunction &MF) {
   // Skew to be applied to alignment.
   unsigned Skew = TFI.getStackAlignmentSkew(MF);
 
+#ifdef EXPENSIVE_CHECKS
+  for (unsigned i = 0, e = MFI.getObjectIndexEnd(); i != e; ++i)
+    if (!MFI.isDeadObjectIndex(i) && MFI.getStackID(i) == 0)
+      assert(MFI.getObjectAlignment(i) <= MFI.getMaxAlignment() &&
+             "MaxAlignment is invalid");
+#endif
+
   // If there are fixed sized objects that are preallocated in the local area,
   // non-fixed objects can't be allocated right at the start of local area.
   // Adjust 'Offset' to point to the end of last fixed sized preallocated
   // object.
   for (int i = MFI.getObjectIndexBegin(); i != 0; ++i) {
+    if (MFI.getStackID(i)) // Only allocate objects on the default stack.
+      continue;
+
     int64_t FixedOff;
     if (StackGrowsDown) {
       // The maximum distance from the stack pointer is at lower address of
@@ -809,6 +822,9 @@ void PEI::calculateFrameObjectOffsets(MachineFunction &MF) {
   // callee saved registers.
   if (StackGrowsDown) {
     for (unsigned i = MinCSFrameIndex; i <= MaxCSFrameIndex; ++i) {
+      if (MFI.getStackID(i)) // Only allocate objects on the default stack.
+        continue;
+
       // If the stack grows down, we need to add the size to find the lowest
       // address of the object.
       Offset += MFI.getObjectSize(i);
@@ -823,6 +839,9 @@ void PEI::calculateFrameObjectOffsets(MachineFunction &MF) {
   } else if (MaxCSFrameIndex >= MinCSFrameIndex) {
     // Be careful about underflow in comparisons agains MinCSFrameIndex.
     for (unsigned i = MaxCSFrameIndex; i != MinCSFrameIndex - 1; --i) {
+      if (MFI.getStackID(i)) // Only allocate objects on the default stack.
+        continue;
+
       if (MFI.isDeadObjectIndex(i))
         continue;
 
@@ -913,6 +932,8 @@ void PEI::calculateFrameObjectOffsets(MachineFunction &MF) {
       if (MFI.getStackProtectorIndex() == (int)i ||
           EHRegNodeFrameIndex == (int)i)
         continue;
+      if (MFI.getStackID(i)) // Only allocate objects on the default stack.
+        continue;
 
       switch (MFI.getObjectSSPLayout(i)) {
       case MachineFrameInfo::SSPLK_None:
@@ -956,6 +977,8 @@ void PEI::calculateFrameObjectOffsets(MachineFunction &MF) {
       continue;
     if (ProtectedObjs.count(i))
       continue;
+    if (MFI.getStackID(i)) // Only allocate objects on the default stack.
+      continue;
 
     // Add the objects that we need to allocate to our working set.
     ObjectsToAllocate.push_back(i);