Print default options selection for -march,-mcpu and -mtune for aarch64 (PR driver/83193).

2018-08-27  Martin Liska  <mliska@suse.cz>

        PR driver/83193
	* config/aarch64/aarch64.c (aarch64_override_options_internal):
        Set default values for x_aarch64_*_string strings.
	* config/aarch64/aarch64.opt: Remove --{march,mcpu,mtune}==
        prefix.  For -mabi do not print '=ABI' in help and use
        <option_value> format for -msve-vector-bits and -moverride
        options.

From-SVN: r263870

gcc/ChangeLog

+2018-08-27  Martin Liska  <mliska@suse.cz>
+
+        PR driver/83193
+	* config/aarch64/aarch64.c (aarch64_override_options_internal):
+        Set default values for x_aarch64_*_string strings.
+	* config/aarch64/aarch64.opt: Remove --{march,mcpu,mtune}==
+        prefix.  For -mabi do not print '=ABI' in help and use
+        <option_value> format for -msve-vector-bits and -moverride
+        options.
+
 2018-08-26  Jeff Law  <law@redhat.com>
 
 	* config/mips/frame-header-opt.c: Include "backend.h" rather than

gcc/config/aarch64/aarch64.c

@@ -10557,6 +10557,13 @@ aarch64_override_options_internal (struct gcc_options *opts)
       && opts->x_optimize >= aarch64_tune_params.prefetch->default_opt_level)
     opts->x_flag_prefetch_loop_arrays = 1;
 
+  if (opts->x_aarch64_arch_string == NULL)
+    opts->x_aarch64_arch_string = selected_arch->name;
+  if (opts->x_aarch64_cpu_string == NULL)
+    opts->x_aarch64_cpu_string = selected_cpu->name;
+  if (opts->x_aarch64_tune_string == NULL)
+    opts->x_aarch64_tune_string = selected_tune->name;
+
   aarch64_override_options_after_change_1 (opts);
 }
 

gcc/config/aarch64/aarch64.opt

@@ -117,23 +117,23 @@ Enum(aarch64_tls_size) String(48) Value(48)
 
 march=
 Target RejectNegative ToLower Joined Var(aarch64_arch_string)
--march=ARCH	Use features of architecture ARCH.
+Use features of architecture ARCH.
 
 mcpu=
 Target RejectNegative ToLower Joined Var(aarch64_cpu_string)
--mcpu=CPU	Use features of and optimize for CPU.
+Use features of and optimize for CPU.
 
 mtune=
 Target RejectNegative ToLower Joined Var(aarch64_tune_string)
--mtune=CPU	Optimize for CPU.
+Optimize for CPU.
 
 mabi=
 Target RejectNegative Joined Enum(aarch64_abi) Var(aarch64_abi) Init(AARCH64_ABI_DEFAULT)
--mabi=ABI	Generate code that conforms to the specified ABI.
+Generate code that conforms to the specified ABI.
 
 moverride=
 Target RejectNegative ToLower Joined Var(aarch64_override_tune_string)
--moverride=STRING	Power users only! Override CPU optimization parameters.
+-moverride=<string>	Power users only! Override CPU optimization parameters.
 
 Enum
 Name(aarch64_abi) Type(int)
@@ -209,7 +209,7 @@ Enum(sve_vector_bits) String(2048) Value(SVE_2048)
 
 msve-vector-bits=
 Target RejectNegative Joined Enum(sve_vector_bits) Var(aarch64_sve_vector_bits) Init(SVE_SCALABLE)
--msve-vector-bits=N	Set the number of bits in an SVE vector register to N.
+-msve-vector-bits=<number>	Set the number of bits in an SVE vector register to N.
 
 mverbose-cost-dump
 Target Undocumented Var(flag_aarch64_verbose_cost)