diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfo.h b/llvm/lib/Target/RISCV/RISCVInstrInfo.h
--- a/llvm/lib/Target/RISCV/RISCVInstrInfo.h
+++ b/llvm/lib/Target/RISCV/RISCVInstrInfo.h
@@ -15,6 +15,7 @@
 
 #include "RISCVRegisterInfo.h"
 #include "llvm/CodeGen/TargetInstrInfo.h"
+#include "llvm/IR/DiagnosticInfo.h"
 
 #define GET_INSTRINFO_HEADER
 #include "RISCVGenInstrInfo.inc"
diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfo.cpp b/llvm/lib/Target/RISCV/RISCVInstrInfo.cpp
--- a/llvm/lib/Target/RISCV/RISCVInstrInfo.cpp
+++ b/llvm/lib/Target/RISCV/RISCVInstrInfo.cpp
@@ -1196,8 +1196,10 @@
     BuildMI(MBB, II, DL, TII->get(RISCV::ADDI), VN)
         .addReg(RISCV::X0)
         .addImm(NumOfVReg);
-    assert(MF.getSubtarget<RISCVSubtarget>().hasStdExtM() &&
-           "M-extension must be enabled to calculate the vscaled size/offset.");
+    if (!MF.getSubtarget<RISCVSubtarget>().hasStdExtM())
+      MF.getFunction().getContext().diagnose(DiagnosticInfoUnsupported{
+          MF.getFunction(),
+          "M-extension must be enabled to calculate the vscaled size/offset."});
     BuildMI(MBB, II, DL, TII->get(RISCV::MUL), FactorRegister)
         .addReg(SizeOfVector, RegState::Kill)
         .addReg(VN, RegState::Kill);