Stop unconditionally adding zicntr_zihpm to extensions

riscv/isa_parser.cc

@@ -32,10 +32,6 @@ isa_parser_t::isa_parser_t(const char* str, const char *priv)
   isa_string = strtolower(str);
   const char* all_subsets = "mafdqchpv";
 
-  // enable zicntr and zihpm unconditionally for backward compatibility
-  extension_table[EXT_ZICNTR] = true;
-  extension_table[EXT_ZIHPM] = true;
-
   if (isa_string.compare(0, 4, "rv32") == 0)
     max_xlen = 32;
   else if (isa_string.compare(0, 4, "rv64") == 0)
@@ -229,9 +225,11 @@ isa_parser_t::isa_parser_t(const char* str, const char *priv)
       extension_table[EXT_ZICBOZ] = true;
     } else if (ext_str == "zicbop") {
     } else if (ext_str == "zicntr") {
+      extension_table[EXT_ZICNTR] = true;
     } else if (ext_str == "zicond") {
       extension_table[EXT_ZICOND] = true;
     } else if (ext_str == "zihpm") {
+      extension_table[EXT_ZIHPM] = true;
     } else if (ext_str == "sstc") {
         extension_table[EXT_SSTC] = true;
     } else if (ext_str[0] == 'x') {