diff a/src/hotspot/cpu/x86/relocInfo_x86.hpp b/src/hotspot/cpu/x86/relocInfo_x86.hpp
--- a/src/hotspot/cpu/x86/relocInfo_x86.hpp
+++ b/src/hotspot/cpu/x86/relocInfo_x86.hpp
@@ -30,11 +30,11 @@
   enum {
     // Intel instructions are byte-aligned.
     offset_unit        =  1,
 
     // Encodes Assembler::disp32_operand vs. Assembler::imm32_operand.
-    // vs Assembler::narrow_oop_operand and ZGC barrier encodings.
+    // vs Assembler::narrow_oop_operand, ZGC and Shenandoah GC barrier encodings.
     format_width       =  3
   };
 
  public: