diff a/src/hotspot/cpu/riscv/riscv.ad b/src/hotspot/cpu/riscv/riscv.ad
--- a/src/hotspot/cpu/riscv/riscv.ad
+++ b/src/hotspot/cpu/riscv/riscv.ad
@@ -1444,17 +1444,10 @@
     ConstantTable& constant_table = C->output()->constant_table();
     constant_table.set_table_base_offset(constant_table.calculate_table_base_offset());
   }
 }
 
-uint MachPrologNode::size(PhaseRegAlloc* ra_) const
-{
-  assert_cond(ra_ != nullptr);
-  return MachNode::size(ra_); // too many variables; just compute it
-                              // the hard way
-}
-
 int MachPrologNode::reloc() const
 {
   return 0;
 }
 
@@ -1510,16 +1503,10 @@
     __ relocate(relocInfo::poll_return_type);
     __ safepoint_poll(*code_stub, true /* at_return */, true /* in_nmethod */);
   }
 }
 
-uint MachEpilogNode::size(PhaseRegAlloc *ra_) const {
-  assert_cond(ra_ != nullptr);
-  // Variable size. Determine dynamically.
-  return MachNode::size(ra_);
-}
-
 int MachEpilogNode::reloc() const {
   // Return number of relocatable values contained in this instruction.
   return 1; // 1 for polling page.
 }
 const Pipeline * MachEpilogNode::pipeline() const {
@@ -1794,10 +1781,22 @@
   }
 }
 
 //=============================================================================
 
+#ifndef PRODUCT
+void MachVEPNode::format(PhaseRegAlloc* ra_, outputStream* st) const
+{
+  Unimplemented();
+}
+#endif
+
+void MachVEPNode::emit(C2_MacroAssembler *masm, PhaseRegAlloc* ra_) const
+{
+  Unimplemented();
+}
+
 #ifndef PRODUCT
 void MachUEPNode::format(PhaseRegAlloc* ra_, outputStream* st) const
 {
   assert_cond(st != nullptr);
   st->print_cr("# MachUEPNode");
@@ -1816,16 +1815,10 @@
 
   // ic_check() aligns to CodeEntryAlignment >= InteriorEntryAlignment(min 16) > NativeInstruction::instruction_size(4).
   assert(((__ offset()) % CodeEntryAlignment) == 0, "Misaligned verified entry point");
 }
 
-uint MachUEPNode::size(PhaseRegAlloc* ra_) const
-{
-  assert_cond(ra_ != nullptr);
-  return MachNode::size(ra_);
-}
-
 // REQUIRED EMIT CODE
 
 //=============================================================================
 
 // Emit deopt handler code.