diff --git a/include/dis-asm.h b/include/dis-asm.h
index c76185f5b3c..04250bd124d 100644
--- a/include/dis-asm.h
+++ b/include/dis-asm.h
@@ -394,6 +394,7 @@ extern bool arm_symbol_is_valid (asymbol *, struct disassemble_info *);
 extern bool csky_symbol_is_valid (asymbol *, struct disassemble_info *);
 extern bool riscv_symbol_is_valid (asymbol *, struct disassemble_info *);
 extern void disassemble_init_powerpc (struct disassemble_info *);
+extern void disassemble_init_riscv (struct disassemble_info *);
 extern void disassemble_init_s390 (struct disassemble_info *);
 extern void disassemble_init_wasm32 (struct disassemble_info *);
 extern void disassemble_init_nds32 (struct disassemble_info *);
diff --git a/opcodes/disassemble.c b/opcodes/disassemble.c
index 8aac42ec96c..5fafa4e797f 100644
--- a/opcodes/disassemble.c
+++ b/opcodes/disassemble.c
@@ -701,7 +701,7 @@ disassemble_init_for_target (struct disassemble_info * info)
 #endif
 #ifdef ARCH_riscv
     case bfd_arch_riscv:
-      info->symbol_is_valid = riscv_symbol_is_valid;
+      disassemble_init_riscv (info);
       info->created_styled_output = true;
       break;
 #endif
diff --git a/opcodes/riscv-dis.c b/opcodes/riscv-dis.c
index 43f449522a9..d83fcfa43a7 100644
--- a/opcodes/riscv-dis.c
+++ b/opcodes/riscv-dis.c
@@ -35,6 +35,12 @@
 /* Current XLEN for the disassembler.  */
 static unsigned xlen = 0;
 
+/* XLEN as inferred by the machine architecture.  */
+static unsigned xlen_by_mach = 0;
+
+/* XLEN as inferred by ELF header.  */
+static unsigned xlen_by_elf = 0;
+
 /* Default ISA specification version (constant as of now).  */
 static enum riscv_spec_class default_isa_spec = ISA_SPEC_CLASS_DRAFT - 1;
 
@@ -75,6 +81,48 @@ static const char * const *riscv_fpr_names;
 
 /* If set, disassemble as most general instruction.  */
 static bool no_aliases = false;
+
+/* If set, disassemble with numeric register names.  */
+static bool is_numeric = false;
+
+
+/* Guess and update current XLEN.  */
+
+static void
+update_riscv_dis_xlen (struct disassemble_info *info)
+{
+  /* Set XLEN with following precedence rules:
+     1. BFD machine architecture set by either:
+       a. -m riscv:rv[32|64] option (GDB: set arch riscv:rv[32|64])
+       b. ELF class in actual ELF header (only on RISC-V ELF)
+       This is only effective if XLEN-specific BFD machine architecture is
+       chosen.  If XLEN-neutral (like riscv), BFD machine architecture is
+       ignored on XLEN selection.
+     2. ELF class in dummy ELF header.  */
+  if (xlen_by_mach != 0)
+    xlen = xlen_by_mach;
+  else if (xlen_by_elf != 0)
+    xlen = xlen_by_elf;
+  else if (info != NULL && info->section != NULL)
+    {
+      Elf_Internal_Ehdr *ehdr = elf_elfheader (info->section->owner);
+      xlen = xlen_by_elf = ehdr->e_ident[EI_CLASS] == ELFCLASS64 ? 64 : 32;
+    }
+}
+
+/* Initialization (for arch and options).  */
+
+static void
+init_riscv_dis_state_for_arch_and_options (void)
+{
+  /* Set GPR register names to disassemble.  */
+  riscv_gpr_names = is_numeric ? riscv_gpr_names_numeric : riscv_gpr_names_abi;
+  /* Set FPR register names to disassemble.  */
+  riscv_fpr_names
+      = !riscv_subset_supports (&riscv_rps_dis, "zfinx")
+	    ? (is_numeric ? riscv_fpr_names_numeric : riscv_fpr_names_abi)
+	    : riscv_gpr_names;
+}
 
 
 /* Set default RISC-V disassembler options.  */
@@ -82,9 +130,8 @@ static bool no_aliases = false;
 static void
 set_default_riscv_dis_options (void)
 {
-  riscv_gpr_names = riscv_gpr_names_abi;
-  riscv_fpr_names = riscv_fpr_names_abi;
   no_aliases = false;
+  is_numeric = false;
 }
 
 /* Parse RISC-V disassembler option (without arguments).  */
@@ -95,10 +142,7 @@ parse_riscv_dis_option_without_args (const char *option)
   if (strcmp (option, "no-aliases") == 0)
     no_aliases = true;
   else if (strcmp (option, "numeric") == 0)
-    {
-      riscv_gpr_names = riscv_gpr_names_numeric;
-      riscv_fpr_names = riscv_fpr_names_numeric;
-    }
+    is_numeric = true;
   else
     return false;
   return true;
@@ -166,8 +210,6 @@ parse_riscv_dis_options (const char *opts_in)
 {
   char *opts = xstrdup (opts_in), *opt = opts, *opt_end = opts;
 
-  set_default_riscv_dis_options ();
-
   for ( ; opt_end != NULL; opt = opt_end + 1)
     {
       if ((opt_end = strchr (opt, ',')) != NULL)
@@ -740,25 +782,6 @@ riscv_disassemble_insn (bfd_vma memaddr,
   matched_op = NULL;
   op = riscv_hash[OP_HASH_IDX (word)];
 
-  /* If XLEN is not known, get its value from the ELF class.  */
-  if (info->mach == bfd_mach_riscv64)
-    xlen = 64;
-  else if (info->mach == bfd_mach_riscv32)
-    xlen = 32;
-  else if (info->section != NULL)
-    {
-      Elf_Internal_Ehdr *ehdr = elf_elfheader (info->section->owner);
-      xlen = ehdr->e_ident[EI_CLASS] == ELFCLASS64 ? 64 : 32;
-    }
-
-  /* If arch has the Zfinx extension, replace FPR with GPR.  */
-  if (riscv_subset_supports (&riscv_rps_dis, "zfinx"))
-    riscv_fpr_names = riscv_gpr_names;
-  else
-    riscv_fpr_names = riscv_gpr_names == riscv_gpr_names_abi
-			  ? riscv_fpr_names_abi
-			  : riscv_fpr_names_numeric;
-
   for (; op && op->name; op++)
     {
       /* Does the opcode match?  */
@@ -892,6 +915,7 @@ riscv_get_map_state (int n,
     {
       riscv_release_subset_list (&riscv_subsets);
       riscv_parse_subset (&riscv_rps_dis, arch);
+      init_riscv_dis_state_for_arch_and_options ();
     }
   return true;
 }
@@ -1156,14 +1180,9 @@ print_insn_riscv (bfd_vma memaddr, struct disassemble_info *info)
   int (*riscv_disassembler) (bfd_vma, insn_t, const bfd_byte *,
 			     struct disassemble_info *);
 
-  if (info->disassembler_options != NULL)
-    {
-      parse_riscv_dis_options (info->disassembler_options);
-      /* Avoid repeatedly parsing the options.  */
-      info->disassembler_options = NULL;
-    }
-  else if (riscv_gpr_names == NULL)
-    set_default_riscv_dis_options ();
+  /* Guess and update XLEN if we haven't determined it yet.  */
+  if (xlen == 0)
+    update_riscv_dis_xlen (info);
 
   if (info->private_data == NULL && !riscv_init_disasm_info (info))
     return -1;
@@ -1230,9 +1249,32 @@ riscv_get_disassembler (bfd *abfd)
 
   riscv_release_subset_list (&riscv_subsets);
   riscv_parse_subset (&riscv_rps_dis, default_arch);
+  init_riscv_dis_state_for_arch_and_options ();
   return print_insn_riscv;
 }
 
+/* Initialize disassemble_info and parse options.  */
+
+void
+disassemble_init_riscv (struct disassemble_info *info)
+{
+  info->symbol_is_valid = riscv_symbol_is_valid;
+  /* Clear previous XLEN and guess by mach.  */
+  xlen = 0;
+  xlen_by_mach = 0;
+  xlen_by_elf = 0;
+  if (info->mach == bfd_mach_riscv64)
+    xlen_by_mach = 64;
+  else if (info->mach == bfd_mach_riscv32)
+    xlen_by_mach = 32;
+  update_riscv_dis_xlen (info);
+  /* Parse disassembler options.  */
+  set_default_riscv_dis_options ();
+  if (info->disassembler_options != NULL)
+    parse_riscv_dis_options (info->disassembler_options);
+  init_riscv_dis_state_for_arch_and_options ();
+}
+
 /* Prevent use of the fake labels that are generated as part of the DWARF
    and for relaxable relocations in the assembler.  */