RISC-V: Refactor riscv_implied_info_t to make it able to handle condi…

…tional implication [NFC]

RISC-V ISA implication rules become little bit complicated than before,
it may come with condition, so this commit extend the capability of
riscv_implied_info_t, also make it more...C++ize.

gcc/ChangeLog:

	* common/config/riscv/riscv-common.cc (riscv_implied_predicator_t): New.
	(riscv_implied_info_t::riscv_implied_info_t): New.
	(riscv_implied_info_t::match): New.
	(riscv_implied_info): New entry for zcf.
	(riscv_subset_list::handle_implied_ext): Use
	riscv_implied_info_t::match.
	(riscv_subset_list::check_implied_ext): Ditto.
	(riscv_subset_list::handle_combine_ext): Ditto.
	(riscv_subset_list::parse): Move zcf implication handling to
	riscv_implied_infos.

gcc/common/config/riscv/riscv-common.cc

@@ -38,11 +38,36 @@ along with GCC; see the file COPYING3.  If not see
 #define TARGET_DEFAULT_TARGET_FLAGS (MASK_BIG_ENDIAN)
 #endif
 
+typedef bool (*riscv_implied_predicator_t) (const riscv_subset_list *);
+
 /* Type for implied ISA info.  */
 struct riscv_implied_info_t
 {
+  constexpr riscv_implied_info_t (const char *ext, const char *implied_ext,
+				  riscv_implied_predicator_t predicator
+				  = nullptr)
+    : ext (ext), implied_ext (implied_ext), predicator (predicator){};
+
+  bool match (const riscv_subset_list *subset_list, const char *ext_name) const
+  {
+    if (strcmp (ext_name, ext) != 0)
+      return false;
+
+    if (predicator && !predicator (subset_list))
+      return false;
+
+    return true;
+  }
+
+  bool match (const riscv_subset_list *subset_list,
+	      const riscv_subset_t *subset) const
+  {
+    return match (subset_list, subset->name.c_str());
+  }
+
   const char *ext;
   const char *implied_ext;
+  riscv_implied_predicator_t predicator;
 };
 
 /* Implied ISA info, must end with NULL sentinel.  */
@@ -143,6 +168,11 @@ static const riscv_implied_info_t riscv_implied_info[] =
   {"zcmp", "zca"},
   {"zcmt", "zca"},
   {"zcmt", "zicsr"},
+  {"zcf", "f",
+   [] (const riscv_subset_list *subset_list) -> bool
+   {
+     return subset_list->xlen () == 32 && subset_list->lookup ("f");
+   }},
 
   {"smaia", "ssaia"},
   {"smstateen", "ssstateen"},
@@ -1093,7 +1123,7 @@ riscv_subset_list::handle_implied_ext (const char *ext)
        implied_info->ext;
        ++implied_info)
     {
-      if (strcmp (ext, implied_info->ext) != 0)
+      if (!implied_info->match (this, ext))
 	continue;
 
       /* Skip if implied extension already present.  */
@@ -1131,7 +1161,7 @@ riscv_subset_list::check_implied_ext ()
       for (implied_info = &riscv_implied_info[0]; implied_info->ext;
 	   ++implied_info)
 	{
-	  if (strcmp (itr->name.c_str(), implied_info->ext) != 0)
+	  if (!implied_info->match (this, itr))
 	    continue;
 
 	  if (!lookup (implied_info->implied_ext))
@@ -1160,8 +1190,7 @@ riscv_subset_list::handle_combine_ext ()
       for (implied_info = &riscv_implied_info[0]; implied_info->ext;
 	   ++implied_info)
 	{
-	  /* Skip if implied extension don't match combine extension */
-	  if (strcmp (combine_info->name, implied_info->ext) != 0)
+	  if (!implied_info->match (this, combine_info->name))
 	    continue;
 
 	  if (lookup (implied_info->implied_ext))
@@ -1502,13 +1531,6 @@ riscv_subset_list::parse (const char *arch, location_t loc)
       subset_list->handle_implied_ext (itr->name.c_str ());
     }
 
-  /* Zce only implies zcf when RV32 and 'f' extension exist.  */
-  if (subset_list->lookup ("zce") != NULL
-	&& subset_list->m_xlen == 32
-	&& subset_list->lookup ("f") != NULL
-	&& subset_list->lookup ("zcf") == NULL)
-    subset_list->add ("zcf", false);
-
   /* Make sure all implied extensions are included. */
   gcc_assert (subset_list->check_implied_ext ());