RISC-V: Comments tidy and improvement.

The GNU coding standards said the comments should be complete sentences
and end with a period and two spaces.  But sometimes it should be more
cleaner when the comments only include a word or codes.  Therefore, I made
the following changes after referring to other target/generic codes,

* Try to write sentences in comments, must end with a period and two spaces.
* End with two spaces without a period for codes/instructions only.
* End with one space without a period for a single word/variable only.

Besids, also rewrite/remove some comments which are obsolete or too long,
and fix indents for comments.

bfd/
    * elfnn-riscv.c: Comments tidy and improvement.
    * elfxx-riscv.c: Likewise.
    * elfxx-riscv.h: Likewise.
gas/
    * config/tc-riscv.c: Comments tidy and improvement.  Also update
    comment "fallthru" to "Fall through" that end with a period and
    two spaces.
include/
    * elf/riscv.h: Comments tidy and improvement.
    * opcode/riscv-opc.h: Likewise.
    * opcode/riscv.h: Likewise.
opcodes/
    * riscv-dis.c: Comments tidy and improvement.
    * riscv-opc.c: Likewise.

4 files changed, 81 insertions, 81 deletions

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index db49d6f..3f349ac1 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,9 @@
+2021-01-15  Nelson Chu  <nelson.chu@sifive.com>
+
+	* elfnn-riscv.c: Comments tidy and improvement.
+	* elfxx-riscv.c: Likewise.
+	* elfxx-riscv.h: Likewise.
+
 2021-01-14  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR ld/26688
diff --git a/bfd/elfnn-riscv.c b/bfd/elfnn-riscv.c
index 098fe9e..c0864c9 100644
--- a/bfd/elfnn-riscv.c
+++ b/bfd/elfnn-riscv.c
@@ -133,7 +133,6 @@ struct riscv_elf_link_hash_table
 };
 
 /* Instruction access functions. */
-
 #define riscv_get_insn(bits, ptr)		\
   ((bits) == 16 ? bfd_getl16 (ptr)		\
    : (bits) == 32 ? bfd_getl32 (ptr)		\
@@ -185,14 +184,11 @@ riscv_is_insn_reloc (const reloc_howto_type *howto)
 }
 
 /* PLT/GOT stuff.  */
-
 #define PLT_HEADER_INSNS 8
 #define PLT_ENTRY_INSNS 4
 #define PLT_HEADER_SIZE (PLT_HEADER_INSNS * 4)
 #define PLT_ENTRY_SIZE (PLT_ENTRY_INSNS * 4)
-
 #define GOT_ENTRY_SIZE RISCV_ELF_WORD_BYTES
-
 /* Reserve two entries of GOTPLT for ld.so, one is used for PLT resolver,
    the other is used for link map.  Other targets also reserve one more
    entry used for runtime profile?  */
@@ -230,7 +226,7 @@ riscv_make_plt_header (bfd *output_bfd, bfd_vma gotplt_addr, bfd_vma addr,
      addi   t0, t2, %lo(.got.plt)    # &.got.plt
      srli   t1, t1, log2(16/PTRSIZE) # .got.plt offset
      l[w|d] t0, PTRSIZE(t0)	     # link map
-     jr	    t3 */
+     jr	    t3  */
 
   entry[0] = RISCV_UTYPE (AUIPC, X_T2, gotplt_offset_high);
   entry[1] = RISCV_RTYPE (SUB, X_T1, X_T1, X_T3);
@@ -261,7 +257,7 @@ riscv_make_plt_entry (bfd *output_bfd, bfd_vma got, bfd_vma addr,
   /* auipc  t3, %hi(.got.plt entry)
      l[w|d] t3, %lo(.got.plt entry)(t3)
      jalr   t1, t3
-     nop */
+     nop  */
 
   entry[0] = RISCV_UTYPE (AUIPC, X_T3, RISCV_PCREL_HIGH_PART (got, addr));
   entry[1] = RISCV_ITYPE (LREG,  X_T3, X_T3, RISCV_PCREL_LOW_PART (got, addr));
@@ -302,9 +298,9 @@ link_hash_newfunc (struct bfd_hash_entry *entry,
 }
 
 /* Compute a hash of a local hash entry.  We use elf_link_hash_entry
-  for local symbol so that we can handle local STT_GNU_IFUNC symbols
-  as global symbol.  We reuse indx and dynstr_index for local symbol
-  hash since they aren't used by global symbols in this backend.  */
+   for local symbol so that we can handle local STT_GNU_IFUNC symbols
+   as global symbol.  We reuse indx and dynstr_index for local symbol
+   hash since they aren't used by global symbols in this backend.  */
 
 static hashval_t
 riscv_elf_local_htab_hash (const void *ptr)
@@ -618,6 +614,7 @@ bad_static_reloc (bfd *abfd, unsigned r_type, struct elf_link_hash_entry *h)
   bfd_set_error (bfd_error_bad_value);
   return FALSE;
 }
+
 /* Look through the relocs for a section during the first phase, and
    allocate space in the global offset table or procedure linkage
    table.  */
@@ -743,8 +740,8 @@ riscv_elf_check_relocs (bfd *abfd, struct bfd_link_info *info,
 
 	case R_RISCV_CALL:
 	case R_RISCV_CALL_PLT:
-	  /* These symbol requires a procedure linkage table entry.  We
-	     actually build the entry in adjust_dynamic_symbol,
+	  /* These symbol requires a procedure linkage table entry.
+	     We actually build the entry in adjust_dynamic_symbol,
 	     because these might be a case of linking PIC code without
 	     linking in any dynamic objects, in which case we don't
 	     need to generate a procedure linkage table after all.  */
@@ -1806,24 +1803,24 @@ riscv_zero_pcrel_hi_reloc (Elf_Internal_Rela *rel,
 			   bfd *input_bfd ATTRIBUTE_UNUSED)
 {
   /* We may need to reference low addreses in PC-relative modes even when the
-   * PC is far away from these addresses.  For example, undefweak references
-   * need to produce the address 0 when linked.  As 0 is far from the arbitrary
-   * addresses that we can link PC-relative programs at, the linker can't
-   * actually relocate references to those symbols.  In order to allow these
-   * programs to work we simply convert the PC-relative auipc sequences to
-   * 0-relative lui sequences.  */
+     PC is far away from these addresses.  For example, undefweak references
+     need to produce the address 0 when linked.  As 0 is far from the arbitrary
+     addresses that we can link PC-relative programs at, the linker can't
+     actually relocate references to those symbols.  In order to allow these
+     programs to work we simply convert the PC-relative auipc sequences to
+     0-relative lui sequences.  */
   if (bfd_link_pic (info))
     return FALSE;
 
   /* If it's possible to reference the symbol using auipc we do so, as that's
-   * more in the spirit of the PC-relative relocations we're processing.  */
+     more in the spirit of the PC-relative relocations we're processing.  */
   bfd_vma offset = addr - pc;
   if (ARCH_SIZE == 32 || VALID_UTYPE_IMM (RISCV_CONST_HIGH_PART (offset)))
     return FALSE;
 
   /* If it's impossible to reference this with a LUI-based offset then don't
-   * bother to convert it at all so users still see the PC-relative relocation
-   * in the truncation message.  */
+     bother to convert it at all so users still see the PC-relative relocation
+     in the truncation message.  */
   if (ARCH_SIZE > 32 && !VALID_UTYPE_IMM (RISCV_CONST_HIGH_PART (addr)))
     return FALSE;
 
@@ -3305,7 +3302,7 @@ riscv_float_abi_string (flagword flags)
     }
 }
 
-/* The information of architecture attribute.  */
+/* The information of architecture elf attributes.  */
 static riscv_subset_list_t in_subsets;
 static riscv_subset_list_t out_subsets;
 static riscv_subset_list_t merged_subsets;
@@ -3382,11 +3379,10 @@ riscv_i_or_e_p (bfd *ibfd,
 
    Arguments:
      `bfd`: bfd handler.
-     `in_arch`: Raw arch string for input object.
-     `out_arch`: Raw arch string for output object.
-     `pin`: subset list for input object, and it'll skip all merged subset after
-            merge.
-     `pout`: Like `pin`, but for output object.  */
+     `in_arch`: Raw ISA string for input object.
+     `out_arch`: Raw ISA string for output object.
+     `pin`: Subset list for input object.
+     `pout`: Subset list for output object.  */
 
 static bfd_boolean
 riscv_merge_std_ext (bfd *ibfd,
@@ -3555,7 +3551,7 @@ riscv_merge_arch_attr_info (bfd *ibfd, char *in_arch, char *out_arch)
   if (in_arch != NULL && out_arch == NULL)
     return in_arch;
 
-  /* Parse subset from arch string.  */
+  /* Parse subset from ISA string.  */
   if (!riscv_parse_subset (&rpe_in, in_arch))
     return NULL;
 
@@ -3660,7 +3656,7 @@ riscv_merge_attributes (bfd *ibfd, struct bfd_link_info *info)
 	else if (in_attr[Tag_RISCV_arch].s
 		 && out_attr[Tag_RISCV_arch].s)
 	  {
-	    /* Check arch compatible.  */
+	    /* Check compatible.  */
 	    char *merged_arch =
 		riscv_merge_arch_attr_info (ibfd,
 					    in_attr[Tag_RISCV_arch].s,
@@ -3678,7 +3674,7 @@ riscv_merge_attributes (bfd *ibfd, struct bfd_link_info *info)
       case Tag_RISCV_priv_spec:
       case Tag_RISCV_priv_spec_minor:
       case Tag_RISCV_priv_spec_revision:
-	/* If we have handled the priv attributes, then skip it.  */
+	/* If we have handled the privileged elf attributes, then skip it.  */
 	if (!priv_attrs_merged)
 	  {
 	    unsigned int Tag_a = Tag_RISCV_priv_spec;
@@ -3687,7 +3683,7 @@ riscv_merge_attributes (bfd *ibfd, struct bfd_link_info *info)
 	    enum riscv_priv_spec_class in_priv_spec;
 	    enum riscv_priv_spec_class out_priv_spec;
 
-	    /* Get the priv spec class from elf attribute numbers.  */
+	    /* Get the privileged spec class from elf attributes.  */
 	    riscv_get_priv_spec_class_from_numbers (in_attr[Tag_a].i,
 						    in_attr[Tag_b].i,
 						    in_attr[Tag_c].i,
@@ -3697,7 +3693,7 @@ riscv_merge_attributes (bfd *ibfd, struct bfd_link_info *info)
 						    out_attr[Tag_c].i,
 						    &out_priv_spec);
 
-	    /* Allow to link the object without the priv specs.  */
+	    /* Allow to link the object without the privileged specs.  */
 	    if (out_priv_spec == PRIV_SPEC_CLASS_NONE)
 	      {
 		out_attr[Tag_a].i = in_attr[Tag_a].i;
@@ -3718,10 +3714,9 @@ riscv_merge_attributes (bfd *ibfd, struct bfd_link_info *info)
 		   out_attr[Tag_b].i,
 		   out_attr[Tag_c].i);
 
-		/* The priv spec v1.9.1 can not be linked with other spec
-		   versions since the conflicts.  We plan to drop the
-		   v1.9.1 in a year or two, so this confict should be
-		   removed in the future.  */
+		/* The privileged spec v1.9.1 can not be linked with others
+		   since the conflicts, so we plan to drop it in a year or
+		   two.  */
 		if (in_priv_spec == PRIV_SPEC_CLASS_1P9P1
 		    || out_priv_spec == PRIV_SPEC_CLASS_1P9P1)
 		  {
@@ -3730,7 +3725,7 @@ riscv_merge_attributes (bfd *ibfd, struct bfd_link_info *info)
 			 "linked with other spec versions"));
 		  }
 
-		/* Update the output priv spec to the newest one.  */
+		/* Update the output privileged spec to the newest one.  */
 		if (in_priv_spec > out_priv_spec)
 		  {
 		    out_attr[Tag_a].i = in_attr[Tag_a].i;
@@ -3938,8 +3933,9 @@ riscv_relax_delete_bytes (bfd *abfd, asection *sec, bfd_vma addr, size_t count,
 	 call to SYMBOL as well. Since both __wrap_SYMBOL and SYMBOL reference
 	 the same symbol (which is __wrap_SYMBOL), but still exist as two
 	 different symbols in 'sym_hashes', we don't want to adjust
-	 the global symbol __wrap_SYMBOL twice.  */
-      /* The same problem occurs with symbols that are versioned_hidden, as
+	 the global symbol __wrap_SYMBOL twice.
+
+         The same problem occurs with symbols that are versioned_hidden, as
 	 foo becomes an alias for foo@BAR, and hence they need the same
 	 treatment.  */
       if (link_info->wrap_hash != NULL
@@ -4177,9 +4173,9 @@ _bfd_riscv_relax_call (bfd *abfd, asection *sec, asection *sym_sec,
       r_type = R_RISCV_JAL;
       auipc = MATCH_JAL | (rd << OP_SH_RD);
     }
-  else /* near_zero */
+  else
     {
-      /* Relax to JALR rd, x0, addr.  */
+      /* Near zero, relax to JALR rd, x0, addr.  */
       r_type = R_RISCV_LO12_I;
       auipc = MATCH_JALR | (rd << OP_SH_RD);
     }
@@ -4212,7 +4208,7 @@ _bfd_riscv_get_max_alignment (asection *sec)
   return (bfd_vma) 1 << max_alignment_power;
 }
 
-/* Relax non-PIC global variable references.  */
+/* Relax non-PIC global variable references to GP-relative references.  */
 
 static bfd_boolean
 _bfd_riscv_relax_lui (bfd *abfd,
@@ -4325,7 +4321,7 @@ _bfd_riscv_relax_lui (bfd *abfd,
   return TRUE;
 }
 
-/* Relax non-PIC TLS references.  */
+/* Relax non-PIC TLS references to TP-relative references.  */
 
 static bfd_boolean
 _bfd_riscv_relax_tls_le (bfd *abfd,
@@ -4446,7 +4442,7 @@ _bfd_riscv_relax_pc  (bfd *abfd ATTRIBUTE_UNUSED,
   BFD_ASSERT (rel->r_offset + 4 <= sec->size);
 
   /* Chain the _LO relocs to their cooresponding _HI reloc to compute the
-   * actual target address.  */
+     actual target address.  */
   riscv_pcgp_hi_reloc hi_reloc;
   memset (&hi_reloc, 0, sizeof (hi_reloc));
   switch (ELFNN_R_TYPE (rel->r_info))
@@ -4486,7 +4482,7 @@ _bfd_riscv_relax_pc  (bfd *abfd ATTRIBUTE_UNUSED,
 	return TRUE;
 
       /* If the cooresponding lo relocation has already been seen then it's not
-       * safe to relax this relocation.  */
+         safe to relax this relocation.  */
       if (riscv_find_pcgp_lo_reloc (pcgp_relocs, rel->r_offset))
 	return TRUE;
 
@@ -4577,7 +4573,7 @@ _bfd_riscv_relax_pc  (bfd *abfd ATTRIBUTE_UNUSED,
   return TRUE;
 }
 
-/* Relax PC-relative references to GP-relative references.  */
+/* Delete the bytes for R_RISCV_DELETE.  */
 
 static bfd_boolean
 _bfd_riscv_relax_delete (bfd *abfd,
@@ -4599,9 +4595,12 @@ _bfd_riscv_relax_delete (bfd *abfd,
   return TRUE;
 }
 
-/* Relax a section.  Pass 0 shortens code sequences unless disabled.  Pass 1
-   deletes the bytes that pass 0 made obselete.  Pass 2, which cannot be
-   disabled, handles code alignment directives.  */
+/* Relax a section.
+
+   Pass 0: Shortens code sequences for LUI/CALL/TPREL relocs.
+   Pass 1: Shortens code sequences for PCREL relocs.
+   Pass 2: Deletes the bytes that pass 1 made obselete.
+   Pass 3: Which cannot be disabled, handles code alignment directives.  */
 
 static bfd_boolean
 _bfd_riscv_relax_section (bfd *abfd, asection *sec,
@@ -4898,7 +4897,7 @@ riscv_elf_grok_prstatus (bfd *abfd, Elf_Internal_Note *note)
       default:
 	return FALSE;
 
-      case PRSTATUS_SIZE:  /* sizeof(struct elf_prstatus) on Linux/RISC-V.  */
+      case PRSTATUS_SIZE: /* sizeof(struct elf_prstatus) on Linux/RISC-V.  */
 	/* pr_cursig */
 	elf_tdata (abfd)->core->signal
 	  = bfd_get_16 (abfd, note->descdata + PRSTATUS_OFFSET_PR_CURSIG);
@@ -4953,6 +4952,7 @@ riscv_elf_grok_psinfo (bfd *abfd, Elf_Internal_Note *note)
 }
 
 /* Set the right mach type.  */
+
 static bfd_boolean
 riscv_elf_object_p (bfd *abfd)
 {
diff --git a/bfd/elfxx-riscv.c b/bfd/elfxx-riscv.c
index 42aeed7..0000bf0 100644
--- a/bfd/elfxx-riscv.c
+++ b/bfd/elfxx-riscv.c
@@ -872,7 +872,6 @@ static reloc_howto_type howto_table[] =
 };
 
 /* A mapping from BFD reloc types to RISC-V ELF reloc types.  */
-
 struct elf_reloc_map
 {
   bfd_reloc_code_real_type bfd_val;
@@ -1025,11 +1024,11 @@ riscv_elf_add_sub_reloc (bfd *abfd,
   return bfd_reloc_ok;
 }
 
-/* Array is used to compare the all extensions' order quickly.
+/* Array is used to compare the orders of all extensions quickly.
 
-   Zero     number means it is a preserved keyword.
-   Negative number means it is a prefix keyword (s, h, x, z).
-   Positive number means it is a standard extension.  */
+   Zero value: Preserved keyword.
+   Negative value: Prefixed keyword (s, h, x, z).
+   Positive value: Standard extension.  */
 
 static int riscv_ext_order[26] = {0};
 
@@ -1093,7 +1092,7 @@ riscv_lookup_subset (const riscv_subset_list_t *subset_list,
   return FALSE;
 }
 
-/* Add arch string extension to the last of the subset list.  */
+/* Add extension from ISA string to the last of the subset list.  */
 
 void
 riscv_add_subset (riscv_subset_list_t *subset_list,
@@ -1150,7 +1149,7 @@ riscv_add_implicit_subset (riscv_subset_list_t *subset_list,
 
 /* These extensions are added to the subset list for special purposes,
    with the explicit versions or the RISCV_UNKNOWN_VERSION versions.
-   Therefore, we won't output them to the output arch string in the
+   Therefore, we won't output them to the output ISA string in the
    riscv_arch_str1, if the versions are unknown.  */
 
 static bfd_boolean
@@ -1163,8 +1162,8 @@ riscv_ext_dont_care_version (const char *subset)
   return FALSE;
 }
 
-/* We have to add all arch string extensions first, and then start to
-   add their implicit extensions.  The arch string extensions must be
+/* We have to add all extensions from ISA string first, and then start to
+   add their implicit extensions.  The extensions from ISA string must be
    set in order, so we can add them to the last of the subset list
    directly, without searching.
 
@@ -1238,7 +1237,7 @@ riscv_release_subset_list (riscv_subset_list_t *subset_list)
 
    Arguments:
      `rps`: Hooks and status for parsing extensions.
-     `march`: Full arch string.
+     `march`: Full ISA string.
      `p`: Curent parsing position.
      `major_version`: Parsed major version.
      `minor_version`: Parsed minor version.
@@ -1323,7 +1322,7 @@ riscv_supported_std_ext (void)
 
    Arguments:
      `rps`: Hooks and status for parsing extensions.
-     `march`: Full arch string.
+     `march`: Full ISA string.
      `p`: Curent parsing position.  */
 
 static const char *
@@ -1379,7 +1378,7 @@ riscv_parse_std_ext (riscv_parse_subset_t *rps,
 				RISCV_UNKNOWN_VERSION,
 				RISCV_UNKNOWN_VERSION, FALSE);
 	/* g-ext is used to add the implicit extensions, but will
-	   not be output to the arch string.  */
+	   not be output to the ISA string.  */
 	riscv_parse_add_subset (rps, "g",
 				major_version,
 				minor_version, FALSE);
@@ -1441,7 +1440,7 @@ riscv_parse_std_ext (riscv_parse_subset_t *rps,
   return p;
 }
 
-/* Classify the argument 'arch' into one of riscv_isa_ext_class_t.  */
+/* Classify ARCH into one of riscv_isa_ext_class_t.  */
 
 riscv_isa_ext_class_t
 riscv_get_prefix_class (const char *arch)
@@ -1457,9 +1456,8 @@ riscv_get_prefix_class (const char *arch)
 }
 
 /* Structure describing parameters to use when parsing a particular
-   riscv_isa_ext_class_t. One of these should be provided for each
+   riscv_isa_ext_class_t.  One of these should be provided for each
    possible class, except RV_ISA_CLASS_UNKNOWN.  */
-
 typedef struct riscv_parse_config
 {
   /* Class of the extension. */
@@ -1481,7 +1479,7 @@ typedef struct riscv_parse_config
 
    Arguments:
      `rps`: Hooks and status for parsing extensions.
-     `march`: Full architecture string.
+     `march`: Full ISA string.
      `p`: Curent parsing position.
      `config`: What class and predicate function to use for the
      extension.  */
@@ -1667,7 +1665,6 @@ riscv_ext_h_valid_p (const char *arg)
 
 /* Parsing order of the prefixed extensions that is specified by
    the ISA spec.  */
-
 static const riscv_parse_config_t parse_config[] =
 {
   {RV_ISA_CLASS_S, "s", riscv_ext_s_valid_p},
@@ -1692,7 +1689,7 @@ riscv_init_ext_order (void)
   if (inited)
     return;
 
-  /* All standard extensions' orders are positive numbers.  */
+  /* The orders of all standard extensions are positive.  */
   order = 1;
 
   /* Init the standard base extensions first.  */
@@ -1703,8 +1700,7 @@ riscv_init_ext_order (void)
   for (ext = std_remain_exts; *ext; ext++)
     riscv_ext_order[(*ext - 'a')] = order++;
 
-  /* Init the order for prefixed keywords.  The orders are
-     negative numbers.  */
+  /* Init the order for prefixed keywords.  The orders are negative.  */
   order = -1;
   for (i = 0; parse_config[i].class != RV_ISA_CLASS_UNKNOWN; i++)
     {
@@ -1715,7 +1711,7 @@ riscv_init_ext_order (void)
   inited = TRUE;
 }
 
-/* Add the implicit extensions according to the arch string extensions.  */
+/* Add the implicit extensions.  */
 
 static void
 riscv_parse_add_implicit_subsets (riscv_parse_subset_t *rps)
@@ -1773,14 +1769,14 @@ riscv_parse_add_implicit_subsets (riscv_parse_subset_t *rps)
     }
 }
 
-/* Function for parsing arch string.
+/* Function for parsing ISA string.
 
    Return Value:
      Return TRUE on success.
 
    Arguments:
      `rps`: Hooks and status for parsing extensions.
-     `arch`: Full arch string.  */
+     `arch`: Full ISA string.  */
 
 bfd_boolean
 riscv_parse_subset (riscv_parse_subset_t *rps,
@@ -1815,11 +1811,11 @@ riscv_parse_subset (riscv_parse_subset_t *rps,
     }
   else
     {
-      /* Arch string shouldn't be NULL or empty here.  However,
-	 it might be empty only when we failed to merge the arch
+      /* ISA string shouldn't be NULL or empty here.  However,
+	 it might be empty only when we failed to merge the ISA
 	 string in the riscv_merge_attributes.  We have already
 	 issued the correct error message in another side, so do
-	 not issue this error when the arch string is empty.  */
+	 not issue this error when the ISA string is empty.  */
       if (strlen (arch))
 	rps->error_handler (
 	  _("-march=%s: ISA string must begin with rv32 or rv64"),
@@ -1903,7 +1899,7 @@ riscv_estimate_arch_strlen1 (const riscv_subset_t *subset)
   return riscv_estimate_arch_strlen1 (subset->next)
 	 + strlen (subset->name)
 	 + riscv_estimate_digit (subset->major_version)
-	 + 1 /* For version seperator: 'p'.  */
+	 + 1 /* For version seperator 'p'.  */
 	 + riscv_estimate_digit (subset->minor_version)
 	 + 1 /* For underscore.  */;
 }
@@ -1928,7 +1924,7 @@ riscv_arch_str1 (riscv_subset_t *subset,
   if (subset_t == NULL)
     return;
 
-  /* No underline between rvXX and i/e.   */
+  /* No underline between rvXX and i/e.  */
   if ((strcasecmp (subset_t->name, "i") == 0)
       || (strcasecmp (subset_t->name, "e") == 0))
     underline = "";
@@ -1953,7 +1949,7 @@ riscv_arch_str1 (riscv_subset_t *subset,
   riscv_arch_str1 (subset_t->next, attr_str, buf, bufsz);
 }
 
-/* Convert subset info to string with explicit version info.  */
+/* Convert subset information into string with explicit versions.  */
 
 char *
 riscv_arch_str (unsigned xlen, const riscv_subset_list_t *subset)
diff --git a/bfd/elfxx-riscv.h b/bfd/elfxx-riscv.h
index 4d7a6dc..87ebaf4 100644
--- a/bfd/elfxx-riscv.h
+++ b/bfd/elfxx-riscv.h
@@ -90,9 +90,7 @@ riscv_arch_str (unsigned, const riscv_subset_list_t *);
 extern size_t
 riscv_estimate_digit (unsigned);
 
-/* ISA extension name class. E.g. "zbb" corresponds to RV_ISA_CLASS_Z,
-   "xargs" corresponds to RV_ISA_CLASS_X, etc.  */
-
+/* ISA extension prefixed name class.  */
 typedef enum riscv_isa_ext_class
 {
   RV_ISA_CLASS_S,