1 files changed, 14 insertions, 0 deletions
diff --git a/llvm/lib/Target/X86/X86MCInstLower.cpp b/llvm/lib/Target/X86/X86MCInstLower.cpp
index 55f0420a928..38d4b1aa647 100644
--- a/llvm/lib/Target/X86/X86MCInstLower.cpp
+++ b/llvm/lib/Target/X86/X86MCInstLower.cpp
@@ -1929,6 +1929,20 @@ void X86AsmPrinter::EmitInstruction(const MachineInstr *MI) {
     return;
   }
 
+  case X86::SEH_NoReturn: {
+    // Materialize an int3 if this instruction is in the last basic block in the
+    // function. The int3 serves the same purpose as the noop emitted above for
+    // SEH_Epilogue, which is to make the Win64 unwinder happy. If the return
+    // address of the preceding call appears to precede an epilogue or a new
+    // function, then the unwinder may get lost.
+    const MachineBasicBlock *MBB = MI->getParent();
+    const MachineBasicBlock *NextMBB = MBB->getNextNode();
+    if (!NextMBB || NextMBB->isEHPad()) {
+      EmitAndCountInstruction(MCInstBuilder(X86::INT3));
+    }
+    return;
+  }
+
   // Lower PSHUFB and VPERMILP normally but add a comment if we can find
   // a constant shuffle mask. We won't be able to do this at the MC layer
   // because the mask isn't an immediate.