1 files changed, 39 insertions, 7 deletions

diff --git a/lib/Target/ARM/ARMFrameLowering.cpp b/lib/Target/ARM/ARMFrameLowering.cpp
index 9e943e44c9..381b404519 100644
--- a/lib/Target/ARM/ARMFrameLowering.cpp
+++ b/lib/Target/ARM/ARMFrameLowering.cpp
@@ -739,20 +739,52 @@ static unsigned GetFunctionSizeInBytes(const MachineFunction &MF,
 /// estimateStackSize - Estimate and return the size of the frame.
 /// FIXME: Make generic?
 static unsigned estimateStackSize(MachineFunction &MF) {
-  const MachineFrameInfo *FFI = MF.getFrameInfo();
+  const MachineFrameInfo *MFI = MF.getFrameInfo();
+  const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
+  const TargetRegisterInfo *RegInfo = MF.getTarget().getRegisterInfo();
+  unsigned MaxAlign = MFI->getMaxAlignment();
   int Offset = 0;
-  for (int i = FFI->getObjectIndexBegin(); i != 0; ++i) {
-    int FixedOff = -FFI->getObjectOffset(i);
+
+  // This code is very, very similar to PEI::calculateFrameObjectOffsets().
+  // It really should be refactored to share code. Until then, changes
+  // should keep in mind that there's tight coupling between the two.
+
+  for (int i = MFI->getObjectIndexBegin(); i != 0; ++i) {
+    int FixedOff = -MFI->getObjectOffset(i);
     if (FixedOff > Offset) Offset = FixedOff;
   }
-  for (unsigned i = 0, e = FFI->getObjectIndexEnd(); i != e; ++i) {
-    if (FFI->isDeadObjectIndex(i))
+  for (unsigned i = 0, e = MFI->getObjectIndexEnd(); i != e; ++i) {
+    if (MFI->isDeadObjectIndex(i))
       continue;
-    Offset += FFI->getObjectSize(i);
-    unsigned Align = FFI->getObjectAlignment(i);
+    Offset += MFI->getObjectSize(i);
+    unsigned Align = MFI->getObjectAlignment(i);
     // Adjust to alignment boundary
     Offset = (Offset+Align-1)/Align*Align;
+
+    MaxAlign = std::max(Align, MaxAlign);
   }
+
+  if (MFI->adjustsStack() && TFI->hasReservedCallFrame(MF))
+    Offset += MFI->getMaxCallFrameSize();
+
+  // Round up the size to a multiple of the alignment.  If the function has
+  // any calls or alloca's, align to the target's StackAlignment value to
+  // ensure that the callee's frame or the alloca data is suitably aligned;
+  // otherwise, for leaf functions, align to the TransientStackAlignment
+  // value.
+  unsigned StackAlign;
+  if (MFI->adjustsStack() || MFI->hasVarSizedObjects() ||
+      (RegInfo->needsStackRealignment(MF) && MFI->getObjectIndexEnd() != 0))
+    StackAlign = TFI->getStackAlignment();
+  else
+    StackAlign = TFI->getTransientStackAlignment();
+
+  // If the frame pointer is eliminated, all frame offsets will be relative to
+  // SP not FP. Align to MaxAlign so this works.
+  StackAlign = std::max(StackAlign, MaxAlign);
+  unsigned AlignMask = StackAlign - 1;
+  Offset = (Offset + AlignMask) & ~uint64_t(AlignMask);
+
   return (unsigned)Offset;
 }