RISC-V: Add zifencei and prefixed h class extensions.

	bfd/
	* elfxx-riscv.c (riscv_parse_std_ext): Stop parsing standard
	extensions when parsed h keyword.
	(riscv_get_prefix_class): Support prefixed h class.
	(riscv_std_h_ext_strtab): Likewise.
	(riscv_ext_h_valid_p): Likewise.
	(parse_config): Likewise.
	(riscv_std_z_ext_strtab): Add zifencei.
	* elfxx-riscv.h (riscv_isa_ext_class): Add RV_ISA_CLASS_H.

	gas/
	* testsuite/gas/riscv/march-fail-order-z.d: New testcase, check
	orders of prefixed z extensions.
	* testsuite/gas/riscv/march-fail-order-z.l: Likewise.
	* testsuite/gas/riscv/march-fail-single-char-h.d: New testcase.
	* testsuite/gas/riscv/march-fail-single-char.l: Updated.
	* testsuite/gas/riscv/march-fail-unknown-h.d: New testcase.
	* testsuite/gas/riscv/march-fail-unknown.l: Updated.

	opcodes/
	* riscv-opc.c (riscv_ext_version_table): Add zifencei.

3 files changed, 31 insertions, 2 deletions

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 3ac2719..726a377 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,5 +1,16 @@
 2020-12-01  Nelson Chu  <nelson.chu@sifive.com>
 
+	* elfxx-riscv.c (riscv_parse_std_ext): Stop parsing standard
+	extensions when parsed h keyword.
+	(riscv_get_prefix_class): Support prefixed h class.
+	(riscv_std_h_ext_strtab): Likewise.
+	(riscv_ext_h_valid_p): Likewise.
+	(parse_config): Likewise.
+	(riscv_std_z_ext_strtab): Add zifencei.
+	* elfxx-riscv.h (riscv_isa_ext_class): Add RV_ISA_CLASS_H.
+
+2020-12-01  Nelson Chu  <nelson.chu@sifive.com>
+
 	* elfxx-riscv.c (riscv_parse_subset): ISA string cannot contain
 	any uppercase letter.
 
diff --git a/bfd/elfxx-riscv.c b/bfd/elfxx-riscv.c
index 69f3a43..24eafcd 100644
--- a/bfd/elfxx-riscv.c
+++ b/bfd/elfxx-riscv.c
@@ -1225,7 +1225,7 @@ riscv_parse_std_ext (riscv_parse_subset_t *rps,
 
   while (p != NULL && *p != '\0')
     {
-      if (*p == 'x' || *p == 's' || *p == 'z')
+      if (*p == 'x' || *p == 's' || *p == 'h' || *p == 'z')
 	break;
 
       if (*p == '_')
@@ -1281,6 +1281,7 @@ riscv_get_prefix_class (const char *arch)
   switch (*arch)
     {
     case 's': return RV_ISA_CLASS_S;
+    case 'h': return RV_ISA_CLASS_H;
     case 'x': return RV_ISA_CLASS_X;
     case 'z': return RV_ISA_CLASS_Z;
     default: return RV_ISA_CLASS_UNKNOWN;
@@ -1362,6 +1363,7 @@ riscv_parse_prefixed_ext (riscv_parse_subset_t *rps,
       /* Check that the prefix extension is known.
 	 For 'x', anything goes but it cannot simply be 'x'.
 	 For 's', it must be known from a list and cannot simply be 's'.
+	 For 'h', it must be known from a list and cannot simply be 'h'.
 	 For 'z', it must be known from a list and cannot simply be 'z'.  */
 
       /* Check that the extension name is well-formed.  */
@@ -1432,7 +1434,7 @@ riscv_parse_prefixed_ext (riscv_parse_subset_t *rps,
 
 static const char * const riscv_std_z_ext_strtab[] =
 {
-  "zicsr", NULL
+  "zicsr", "zifencei", NULL
 };
 
 static const char * const riscv_std_s_ext_strtab[] =
@@ -1440,6 +1442,11 @@ static const char * const riscv_std_s_ext_strtab[] =
   NULL
 };
 
+static const char * const riscv_std_h_ext_strtab[] =
+{
+  NULL
+};
+
 /* For the extension `ext`, search through the list of known extensions
    `known_exts` for a match, and return TRUE if found.  */
 
@@ -1486,12 +1493,22 @@ riscv_ext_s_valid_p (const char *arg)
   return riscv_multi_letter_ext_valid_p (arg, riscv_std_s_ext_strtab);
 }
 
+/* Predicator function for 'h' prefixed extensions.
+   Only known h-extensions are permitted.  */
+
+static bfd_boolean
+riscv_ext_h_valid_p (const char *arg)
+{
+  return riscv_multi_letter_ext_valid_p (arg, riscv_std_h_ext_strtab);
+}
+
 /* 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},
+  {RV_ISA_CLASS_H, "h", riscv_ext_h_valid_p},
   {RV_ISA_CLASS_Z, "z", riscv_ext_z_valid_p},
   {RV_ISA_CLASS_X, "x", riscv_ext_x_valid_p},
   {RV_ISA_CLASS_UNKNOWN, NULL, NULL}
diff --git a/bfd/elfxx-riscv.h b/bfd/elfxx-riscv.h
index b5b17d1..6b7cc5b 100644
--- a/bfd/elfxx-riscv.h
+++ b/bfd/elfxx-riscv.h
@@ -102,6 +102,7 @@ riscv_estimate_digit (unsigned);
 typedef enum riscv_isa_ext_class
 {
   RV_ISA_CLASS_S,
+  RV_ISA_CLASS_H,
   RV_ISA_CLASS_Z,
   RV_ISA_CLASS_X,
   RV_ISA_CLASS_UNKNOWN