RISC-V: Update march parser

 - The arch string rule has changed in latest spec, it introduced new
   multi-letter extension prefix with 'h' and 'z', and drop `sx`. also
   adjust parsing order for 's' and 'x'.

gcc/ChangeLog

	* riscv-common.c (parse_sv_or_non_std_ext): Rename to
	parse_multiletter_ext.
	(parse_multiletter_ext): Add parsing `h` and `z`, drop `sx`,
	adjust parsing order for 's' and 'x'.

gcc/testsuite/ChangeLog

	* gcc.target/riscv/arch-3.c: Adjust option.
	* gcc.target/riscv/arch-5.c: New.
	* gcc.target/riscv/attribute-9.c: Adjust option and test
	condition.

gcc/common/config/riscv/riscv-common.c

@@ -70,7 +70,7 @@ private:
 
   const char *parse_std_ext (const char *);
 
-  const char *parse_sv_or_non_std_ext (const char *, const char *,
+  const char *parse_multiletter_ext (const char *, const char *,
 				     const char *);
 
 public:
@@ -357,7 +357,7 @@ riscv_subset_list::parse_std_ext (const char *p)
     {
       char subset[2] = {0, 0};
 
-      if (*p == 'x' || *p == 's')
+      if (*p == 'x' || *p == 's' || *p == 'h' || *p == 'z')
 	break;
 
       if (*p == '_')
@@ -399,18 +399,18 @@ riscv_subset_list::parse_std_ext (const char *p)
   return p;
 }
 
-/* Parsing function for non-standard and supervisor extensions.
+/* Parsing function for multi-letter extensions.
 
    Return Value:
      Points to the end of extensions.
 
    Arguments:
      `p`: Current parsing position.
-     `ext_type`: What kind of extensions, 'x', 's' or 'sx'.
+     `ext_type`: What kind of extensions, 's', 'h', 'z' or 'x'.
      `ext_type_str`: Full name for kind of extension.  */
 
 const char *
-riscv_subset_list::parse_sv_or_non_std_ext (const char *p,
+riscv_subset_list::parse_multiletter_ext (const char *p,
 					  const char *ext_type,
 					  const char *ext_type_str)
 {
@@ -429,11 +429,6 @@ riscv_subset_list::parse_sv_or_non_std_ext (const char *p,
       if (strncmp (p, ext_type, ext_type_len) != 0)
 	break;
 
-      /* It's non-standard supervisor extension if it prefix with sx.  */
-      if ((ext_type[0] == 's') && (ext_type_len == 1)
-	  && (*(p + 1) == 'x'))
-	break;
-
       char *subset = xstrdup (p);
       char *q = subset;
       const char *end_of_version;
@@ -494,21 +489,26 @@ riscv_subset_list::parse (const char *arch, location_t loc)
   if (p == NULL)
     goto fail;
 
-  /* Parsing non-standard extension.  */
-  p = subset_list->parse_sv_or_non_std_ext (p, "x", "non-standard extension");
+  /* Parsing supervisor extension.  */
+  p = subset_list->parse_multiletter_ext (p, "s", "supervisor extension");
 
   if (p == NULL)
     goto fail;
 
-  /* Parsing supervisor extension.  */
-  p = subset_list->parse_sv_or_non_std_ext (p, "s", "supervisor extension");
+  /* Parsing hypervisor extension.  */
+  p = subset_list->parse_multiletter_ext (p, "h", "hypervisor extension");
 
   if (p == NULL)
     goto fail;
 
-  /* Parsing non-standard supervisor extension.  */
-  p = subset_list->parse_sv_or_non_std_ext
-    (p, "sx", "non-standard supervisor extension");
+  /* Parsing sub-extensions.  */
+  p = subset_list->parse_multiletter_ext (p, "z", "sub-extension");
+
+  if (p == NULL)
+    goto fail;
+
+  /* Parsing non-standard extension.  */
+  p = subset_list->parse_multiletter_ext (p, "x", "non-standard extension");
 
   if (p == NULL)
     goto fail;

gcc/testsuite/gcc.target/riscv/arch-3.c

 /* { dg-do compile } */
-/* { dg-options "-O -march=rv32ixbar_sabc_sxfoo -mabi=ilp32" } */
+/* { dg-options "-O -march=rv32isabc_xbar -mabi=ilp32" } */
 int foo()
 {
 }

gcc/testsuite/gcc.target/riscv/arch-5.c

+/* { dg-do compile } */
+/* { dg-options "-O -march=rv32isabc_hghi_zfoo_xbar -mabi=ilp32" } */
+int foo()
+{
+}

gcc/testsuite/gcc.target/riscv/attribute-9.c

 /* { dg-do compile } */
-/* { dg-options "-O -mriscv-attribute -march=rv32i2p0xbar_sabc_sxfoo -mabi=ilp32e" } */
+/* { dg-options "-O -mriscv-attribute -march=rv32i2p0sabc_xbar -mabi=ilp32e" } */
 int foo()
 {
 }
-/* { dg-final { scan-assembler ".attribute arch, \"rv32i2p0_xbar2p0_sabc2p0_sxfoo2p0\"" } } */
+/* { dg-final { scan-assembler ".attribute arch, \"rv32i2p0_sabc2p0_xbar2p0\"" } } */