RISC-V: Support --target-help for -mcpu/-mtune

gcc/ChangeLog:

	* common/config/riscv/riscv-common.cc (riscv_tunes): New.
	(riscv_get_valid_option_values): New.
	(TARGET_GET_VALID_OPTION_VALUES): New.
	* config/riscv/riscv-cores.def (RISCV_TUNE): New, define options
	for tune here.
	(RISCV_CORE): Fix comment.
	* config/riscv/riscv.cc (riscv_tune_info_table): Move definition to
	riscv-cores.def.

1 files changed, 46 insertions, 0 deletions

diff --git a/gcc/common/config/riscv/riscv-common.cc b/gcc/common/config/riscv/riscv-common.cc
index c39ed2e..697bfe4 100644
--- a/gcc/common/config/riscv/riscv-common.cc
+++ b/gcc/common/config/riscv/riscv-common.cc
@@ -224,6 +224,14 @@ static const riscv_cpu_info riscv_cpu_tables[] =
     {NULL, NULL, NULL}
 };
 
+static const char *riscv_tunes[] =
+{
+#define RISCV_TUNE(TUNE_NAME, PIPELINE_MODEL, TUNE_INFO) \
+    TUNE_NAME,
+#include "../../../config/riscv/riscv-cores.def"
+    NULL
+};
+
 static const char *riscv_supported_std_ext (void);
 
 static riscv_subset_list *current_subset_list = NULL;
@@ -1683,6 +1691,41 @@ riscv_compute_multilib (
     return xstrdup (multilib_infos[best_match_multi_lib].path.c_str ());
 }
 
+vec<const char *>
+riscv_get_valid_option_values (int option_code,
+			       const char *prefix ATTRIBUTE_UNUSED)
+{
+  vec<const char *> v;
+  v.create (0);
+  opt_code opt = (opt_code) option_code;
+
+  switch (opt)
+    {
+    case OPT_mtune_:
+      {
+	const char **tune = &riscv_tunes[0];
+	for (;*tune; ++tune)
+	  v.safe_push (*tune);
+
+	const riscv_cpu_info *cpu_info = &riscv_cpu_tables[0];
+	for (;cpu_info->name; ++cpu_info)
+	  v.safe_push (cpu_info->name);
+      }
+      break;
+    case OPT_mcpu_:
+      {
+	const riscv_cpu_info *cpu_info = &riscv_cpu_tables[0];
+	for (;cpu_info->name; ++cpu_info)
+	  v.safe_push (cpu_info->name);
+      }
+      break;
+    default:
+      break;
+    }
+
+  return v;
+}
+
 #undef TARGET_COMPUTE_MULTILIB
 #define TARGET_COMPUTE_MULTILIB riscv_compute_multilib
 #endif
@@ -1701,4 +1744,7 @@ static const struct default_options riscv_option_optimization_table[] =
 #undef TARGET_HANDLE_OPTION
 #define TARGET_HANDLE_OPTION riscv_handle_option
 
+#undef  TARGET_GET_VALID_OPTION_VALUES
+#define TARGET_GET_VALID_OPTION_VALUES riscv_get_valid_option_values
+
 struct gcc_targetm_common targetm_common = TARGETM_COMMON_INITIALIZER;