diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp
index 2c53eade6cd59..b12437b2afed6 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp
@@ -453,8 +453,6 @@ static void EmitGCCInlineAsmStr(const char *AsmStr, const MachineInstr *MI,
           } else if (MI->getOperand(OpNo).isMBB()) {
             const MCSymbol *Sym = MI->getOperand(OpNo).getMBB()->getSymbol();
             Sym->print(OS, AP->MAI);
-          } else if (Modifier[0] == 'l') {
-            Error = true;
           } else if (InlineAsm::isMemKind(OpFlags)) {
             Error = AP->PrintAsmMemoryOperand(
                 MI, OpNo, Modifier[0] ? Modifier : nullptr, OS);
diff --git a/llvm/lib/Target/AVR/AVRAsmPrinter.cpp b/llvm/lib/Target/AVR/AVRAsmPrinter.cpp
index 73f0a0961d6bd..259ab1bc7aec7 100644
--- a/llvm/lib/Target/AVR/AVRAsmPrinter.cpp
+++ b/llvm/lib/Target/AVR/AVRAsmPrinter.cpp
@@ -144,9 +144,8 @@ bool AVRAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNum,
 bool AVRAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
                                           unsigned OpNum, const char *ExtraCode,
                                           raw_ostream &O) {
-  if (ExtraCode && ExtraCode[0]) {
-    llvm_unreachable("This branch is not implemented yet");
-  }
+  if (ExtraCode && ExtraCode[0])
+    return true; // Unknown modifier
 
   const MachineOperand &MO = MI->getOperand(OpNum);
   (void)MO;
diff --git a/llvm/test/CodeGen/AVR/inline-asm/inline-asm-invalid.ll b/llvm/test/CodeGen/AVR/inline-asm/inline-asm-invalid.ll
new file mode 100644
index 0000000000000..81b0f6e9b2832
--- /dev/null
+++ b/llvm/test/CodeGen/AVR/inline-asm/inline-asm-invalid.ll
@@ -0,0 +1,10 @@
+; RUN: not llc < %s -march=avr -no-integrated-as 2>&1 | FileCheck %s
+
+define void @foo(i16 %a) {
+  ; CHECK: error: invalid operand in inline asm: 'jl ${0:l}'
+  %i.addr = alloca i32, align 4
+  call void asm sideeffect "jl ${0:l}", "*m"(i32* %i.addr)
+
+  ret void
+}
+