1 files changed, 43 insertions, 0 deletions

diff --git a/llvm/lib/Target/X86/X86FrameLowering.cpp b/llvm/lib/Target/X86/X86FrameLowering.cpp
index c7af0ae43d2..86e65b83ffa 100644
--- a/llvm/lib/Target/X86/X86FrameLowering.cpp
+++ b/llvm/lib/Target/X86/X86FrameLowering.cpp
@@ -1562,6 +1562,11 @@ void X86FrameLowering::emitEpilogue(MachineFunction &MF,
   bool HasFP = hasFP(MF);
   uint64_t NumBytes = 0;
 
+  bool NeedsDwarfCFI =
+      (!MF.getTarget().getTargetTriple().isOSDarwin() &&
+       !MF.getTarget().getTargetTriple().isOSWindows()) &&
+      (MF.getMMI().hasDebugInfo() || MF.getFunction()->needsUnwindTableEntry());
+
   if (IsFunclet) {
     assert(HasFP && "EH funclets without FP not yet implemented");
     NumBytes = getWinEHFuncletFrameSize(MF);
@@ -1584,6 +1589,13 @@ void X86FrameLowering::emitEpilogue(MachineFunction &MF,
     BuildMI(MBB, MBBI, DL, TII.get(Is64Bit ? X86::POP64r : X86::POP32r),
             MachineFramePtr)
         .setMIFlag(MachineInstr::FrameDestroy);
+    if (NeedsDwarfCFI) {
+      unsigned DwarfStackPtr =
+          TRI->getDwarfRegNum(Is64Bit ? X86::RSP : X86::ESP, true);
+      BuildCFI(MBB, MBBI, DL, MCCFIInstruction::createDefCfa(
+                                  nullptr, DwarfStackPtr, -SlotSize));
+      --MBBI;
+    }
   }
 
   MachineBasicBlock::iterator FirstCSPop = MBBI;
@@ -1647,6 +1659,11 @@ void X86FrameLowering::emitEpilogue(MachineFunction &MF,
   } else if (NumBytes) {
     // Adjust stack pointer back: ESP += numbytes.
     emitSPUpdate(MBB, MBBI, NumBytes, /*InEpilogue=*/true);
+    if (!hasFP(MF) && NeedsDwarfCFI) {
+      // Define the current CFA rule to use the provided offset.
+      BuildCFI(MBB, MBBI, DL, MCCFIInstruction::createDefCfaOffset(
+                                  nullptr, -CSSize - SlotSize));
+    }
     --MBBI;
   }
 
@@ -1659,6 +1676,23 @@ void X86FrameLowering::emitEpilogue(MachineFunction &MF,
   if (NeedsWin64CFI && MF.hasWinCFI())
     BuildMI(MBB, MBBI, DL, TII.get(X86::SEH_Epilogue));
 
+  if (!hasFP(MF) && NeedsDwarfCFI) {
+    MBBI = FirstCSPop;
+    int64_t Offset = -CSSize - SlotSize;
+    // Mark callee-saved pop instruction.
+    // Define the current CFA rule to use the provided offset.
+    while (MBBI != MBB.end()) {
+      MachineBasicBlock::iterator PI = MBBI;
+      unsigned Opc = PI->getOpcode();
+      ++MBBI;
+      if (Opc == X86::POP32r || Opc == X86::POP64r) {
+        Offset += SlotSize;
+        BuildCFI(MBB, MBBI, DL,
+                 MCCFIInstruction::createDefCfaOffset(nullptr, Offset));
+      }
+    }
+  }
+
   if (Terminator == MBB.end() || !isTailCallOpcode(Terminator->getOpcode())) {
     // Add the return addr area delta back since we are not tail calling.
     int Offset = -1 * X86FI->getTCReturnAddrDelta();
@@ -2840,6 +2874,15 @@ MachineBasicBlock::iterator X86FrameLowering::restoreWin32EHStackPointers(
   return MBBI;
 }
 
+int X86FrameLowering::getInitialCFAOffset(const MachineFunction &MF) const {
+  return TRI->getSlotSize();
+}
+
+unsigned X86FrameLowering::getInitialCFARegister(const MachineFunction &MF)
+    const {
+  return TRI->getDwarfRegNum(StackPtr, true);
+}
+
 namespace {
 // Struct used by orderFrameObjects to help sort the stack objects.
 struct X86FrameSortingObject {