RISC-V: Record implicit subsets in a table, to avoid repeated codes.

Add a new table, riscv_implicit_subsets, to record all implicit information.
So that we add all implicit subsets according to the table, to avoid too
many repeated codes in the riscv_parse_add_implicit_subsets.  Besides, the
check_func is used to check whether we should add this implicit subset.
For example, check_implicit_for_i checks the version of i, and we only add
zicsr and zifencei implicitly only when the version less than 2.1.

bfd/
    * elfxx-riscv.c (check_implicit_always): The check_func, always add
    the implicit subset without checking.
    (check_implicit_for_i): The check_func for i, only add zicsr and
    zifencei when the version of i less than 2.1.
    (struct riscv_implicit_subset): Record the subsets and their
    corresponding implicit subsets.
    (riscv_implicit_subsets): Table records all implicit informations.
    (riscv_parse_add_implicit_subsets): Updated and add implicit subsets
    according to riscv_implicit_subsets.  Remove the redundant codes.

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index fcb692bdb3553d84fa4eee0db82b2151100f3e4f..8dbe40c474d406706e4126c0c69d63d5912b7f42 100644 (file)
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,15 @@
+2021-05-13  Nelson Chu  <nelson.chu@sifive.com>
+
+       * elfxx-riscv.c (check_implicit_always): The check_func, always add
+       the implicit subset without checking.
+       (check_implicit_for_i): The check_func for i, only add zicsr and
+       zifencei when the version of i less than 2.1.
+       (struct riscv_implicit_subset): Record the subsets and their
+       corresponding implicit subsets.
+       (riscv_implicit_subsets): Table records all implicit informations.
+       (riscv_parse_add_implicit_subsets): Updated and add implicit subsets
+       according to riscv_implicit_subsets.  Remove the redundant codes.
+
 2021-05-13  Alan Modra  <amodra@gmail.com>
 
        PR 27858

diff --git a/bfd/elfxx-riscv.c b/bfd/elfxx-riscv.c
index 3b381925758c1e46b4db7798022a8715a12d05c5..7206ec8573bdef6bada4e54fea20195d6c4ea118 100644 (file)
--- a/bfd/elfxx-riscv.c
+++ b/bfd/elfxx-riscv.c
@@ -1026,6 +1026,47 @@ riscv_elf_add_sub_reloc (bfd *abfd,
   return bfd_reloc_ok;
 }
 
+/* Always add the IMPLICIT for the SUBSET.  */
+
+static bool
+check_implicit_always (const char *implicit ATTRIBUTE_UNUSED,
+                      riscv_subset_t *subset ATTRIBUTE_UNUSED)
+{
+  return true;
+}
+
+/* Add the IMPLICIT only when the version of SUBSET less than 2.1.  */
+
+static bool
+check_implicit_for_i (const char *implicit ATTRIBUTE_UNUSED,
+                     riscv_subset_t *subset)
+{
+  return (subset->major_version < 2
+         || (subset->major_version == 2
+             && subset->minor_version < 1));
+}
+
+/* Record all implicit information for the subsets.  */
+struct riscv_implicit_subset
+{
+  const char *subset_name;
+  const char *implicit_name;
+  /* A function to determine if we need to add the implicit subset.  */
+  bool (*check_func) (const char *, riscv_subset_t *);
+};
+static struct riscv_implicit_subset riscv_implicit_subsets[] =
+{
+  {"e", "i",           check_implicit_always},
+  {"i", "zicsr",       check_implicit_for_i},
+  {"i", "zifencei",    check_implicit_for_i},
+  {"g", "zicsr",       check_implicit_always},
+  {"g", "zifencei",    check_implicit_always},
+  {"q", "d",           check_implicit_always},
+  {"d", "f",           check_implicit_always},
+  {"f", "zicsr",       check_implicit_always},
+  {NULL, NULL, NULL}
+};
+
 /* Lists of prefixed class extensions that binutils should know about.
    Whether or not a particular entry is in these lists will dictate if
    gas/ld will accept its presence in the architecture string.
@@ -1694,61 +1735,15 @@ riscv_parse_prefixed_ext (riscv_parse_subset_t *rps,
 static void
 riscv_parse_add_implicit_subsets (riscv_parse_subset_t *rps)
 {
-  riscv_subset_t *subset = NULL;
-
-  if (riscv_lookup_subset (rps->subset_list, "e", &subset))
-    riscv_parse_add_subset (rps, "i",
-                           RISCV_UNKNOWN_VERSION,
-                           RISCV_UNKNOWN_VERSION, true);
-
-  /* Add the zicsr and zifencei only when the i's version less than 2.1.  */
-  if (riscv_lookup_subset (rps->subset_list, "i", &subset)
-      && (subset->major_version < 2
-         || (subset->major_version == 2
-             && subset->minor_version < 1)))
-    {
-      riscv_parse_add_subset (rps, "zicsr",
-                             RISCV_UNKNOWN_VERSION,
-                             RISCV_UNKNOWN_VERSION, true);
-      riscv_parse_add_subset (rps, "zifencei",
-                             RISCV_UNKNOWN_VERSION,
-                             RISCV_UNKNOWN_VERSION, true);
-    }
-
-  if (riscv_lookup_subset (rps->subset_list, "q", &subset))
+  struct riscv_implicit_subset *t = riscv_implicit_subsets;
+  for (; t->subset_name; t++)
     {
-      riscv_parse_add_subset (rps, "d",
-                             RISCV_UNKNOWN_VERSION,
-                             RISCV_UNKNOWN_VERSION, true);
-      riscv_parse_add_subset (rps, "f",
-                             RISCV_UNKNOWN_VERSION,
-                             RISCV_UNKNOWN_VERSION, true);
-      riscv_parse_add_subset (rps, "zicsr",
-                             RISCV_UNKNOWN_VERSION,
-                             RISCV_UNKNOWN_VERSION, true);
-    }
-  else if (riscv_lookup_subset (rps->subset_list, "d", &subset))
-    {
-      riscv_parse_add_subset (rps, "f",
-                             RISCV_UNKNOWN_VERSION,
-                             RISCV_UNKNOWN_VERSION, true);
-      riscv_parse_add_subset (rps, "zicsr",
-                             RISCV_UNKNOWN_VERSION,
-                             RISCV_UNKNOWN_VERSION, true);
-    }
-  else if (riscv_lookup_subset (rps->subset_list, "f", &subset))
-    riscv_parse_add_subset (rps, "zicsr",
-                           RISCV_UNKNOWN_VERSION,
-                           RISCV_UNKNOWN_VERSION, true);
-
-  if (riscv_lookup_subset (rps->subset_list, "g", &subset))
-    {
-      riscv_parse_add_subset (rps, "zicsr",
-                             RISCV_UNKNOWN_VERSION,
-                             RISCV_UNKNOWN_VERSION, true);
-      riscv_parse_add_subset (rps, "zifencei",
-                             RISCV_UNKNOWN_VERSION,
-                             RISCV_UNKNOWN_VERSION, true);
+      riscv_subset_t *subset = NULL;
+      if (riscv_lookup_subset (rps->subset_list, t->subset_name, &subset)
+         && t->check_func (t->implicit_name, subset))
+       riscv_parse_add_subset (rps, t->implicit_name,
+                               RISCV_UNKNOWN_VERSION,
+                               RISCV_UNKNOWN_VERSION, true);
     }
 }