Fix interaction of CFI instructions with MachineOutliner.

1. When checking if a candidate contains a CFI instruction, actually
iterate over all of the instructions, instead of stopping halfway
through.
2. Make sure copied CFI directives refer to the correct instruction.

Fixes https://github.com/llvm/llvm-project/issues/55842

Differential Revision: https://reviews.llvm.org/D126930

1 files changed, 11 insertions, 8 deletions

diff --git a/llvm/lib/CodeGen/MachineOutliner.cpp b/llvm/lib/CodeGen/MachineOutliner.cpp
index 7ab69968b607..5da68abc8f6a 100644
--- a/llvm/lib/CodeGen/MachineOutliner.cpp
+++ b/llvm/lib/CodeGen/MachineOutliner.cpp
@@ -665,17 +665,20 @@ MachineFunction *MachineOutliner::createOutlinedFunction(
        ++I) {
     if (I->isDebugInstr())
       continue;
-    MachineInstr *NewMI = MF.CloneMachineInstr(&*I);
+
+    // Don't keep debug information for outlined instructions.
+    auto DL = DebugLoc();
     if (I->isCFIInstruction()) {
-      unsigned CFIIndex = NewMI->getOperand(0).getCFIIndex();
+      unsigned CFIIndex = I->getOperand(0).getCFIIndex();
       MCCFIInstruction CFI = Instrs[CFIIndex];
-      (void)MF.addFrameInst(CFI);
+      BuildMI(MBB, MBB.end(), DL, TII.get(TargetOpcode::CFI_INSTRUCTION))
+          .addCFIIndex(MF.addFrameInst(CFI));
+    } else {
+      MachineInstr *NewMI = MF.CloneMachineInstr(&*I);
+      NewMI->dropMemRefs(MF);
+      NewMI->setDebugLoc(DL);
+      MBB.insert(MBB.end(), NewMI);
     }
-    NewMI->dropMemRefs(MF);
-
-    // Don't keep debug information for outlined instructions.
-    NewMI->setDebugLoc(DebugLoc());
-    MBB.insert(MBB.end(), NewMI);
   }
 
   // Set normal properties for a late MachineFunction.