diff --git a/llvm/lib/Target/AMDGPU/SIRegisterInfo.td b/llvm/lib/Target/AMDGPU/SIRegisterInfo.td
index 81655f5a829fb..0293d4018770f 100644
--- a/llvm/lib/Target/AMDGPU/SIRegisterInfo.td
+++ b/llvm/lib/Target/AMDGPU/SIRegisterInfo.td
@@ -1166,7 +1166,8 @@ class RegOrImmOperand <RegisterClass RegClass, string OperandTypeName>
 }
 
 //===----------------------------------------------------------------------===//
-//  SSrc_* Operands with an SGPR or a 32-bit immediate
+//  SSrc_* Operands with an SGPR, a 32-bit immediate, or 64-bit immediate
+//  if supported by target.
 //===----------------------------------------------------------------------===//
 
 class SrcRegOrImm9<RegisterClass regClass, string operandType>