[NDS32] Basic support for -mcpu= and --with-cpu= options.

gcc/
	* config.gcc: Add --with-cpu support for nds32 target.
	* config/nds32/nds32-opts.h(nds32_cpu_type): New.
	* config/nds32/nds32.opt: Add -mcpu= option.

From-SVN: r257982

gcc/ChangeLog

+2018-02-26  Kito Cheng  <kito.cheng@gmail.com>
+
+	* config.gcc: Add --with-cpu support for nds32 target.
+	* config/nds32/nds32-opts.h(nds32_cpu_type): New.
+	* config/nds32/nds32.opt: Add -mcpu= option.
+
 2018-02-25  Segher Boessenkool  <segher@kernel.crashing.org>
 
 	* config/rs6000/rs6000.opt (mvrsave=no, mvrsave=yes, isel=no,

gcc/config.gcc

@@ -4265,7 +4265,7 @@ case "${target}" in
 		;;
 
 	nds32*-*-*)
-		supported_defaults="arch nds32_lib"
+		supported_defaults="arch cpu nds32_lib"
 
 		# process --with-arch
 		case "${with_arch}" in
@@ -4278,6 +4278,19 @@ case "${target}" in
 			;;
 		esac
 
+		case "${with_cpu}" in
+		"")
+			with_cpu=n9
+			;;
+		n9)
+			# OK
+			;;
+		*)
+			echo "Cannot accept --with-cpu=$with_cpu, available values are: n9" 1>&2
+			exit 1
+			;;
+		esac
+
 		# process --with-nds32-lib
 		case "${with_nds32_lib}" in
 		"")

gcc/config/nds32/nds32-opts.h

@@ -40,4 +40,10 @@ enum nds32_cmodel_type
   CMODEL_LARGE
 };
 
+/* The various ANDES CPU.  */
+enum nds32_cpu_type
+{
+  CPU_N9
+};
+
 #endif

gcc/config/nds32/nds32.opt

@@ -119,6 +119,17 @@ Enum(nds32_cmodel_type) String(medium) Value(CMODEL_MEDIUM)
 EnumValue
 Enum(nds32_cmodel_type) String(large) Value(CMODEL_LARGE)
 
+mcpu=
+Target RejectNegative Joined Enum(nds32_cpu_type) Var(nds32_cpu_option) Init(CPU_N9)
+Specify the cpu for pipeline model.
+
+Enum
+Name(nds32_cpu_type) Type(enum nds32_cpu_type)
+Known cpu types (for use with the -mcpu= option):
+
+EnumValue
+Enum(nds32_cpu_type) String(n9) Value(CPU_N9)
+
 mctor-dtor
 Target Report
 Enable constructor/destructor feature.