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

[Richard Earnshaw (lists)]

On 18/07/18 16:48, Martin Liška wrote:
> Hi.
> 
> This is aarch64 fix for PR83193. It's about setting of default options
> so that --help=target -Q prints proper numbers:
> 
> Now this is seen on my cross-compiler:
> 
> --- /home/marxin/Downloads/options-2-before.txt	2018-07-18 14:53:11.658146543 +0200
> +++ /home/marxin/Downloads/options-2.txt	2018-07-18 14:52:30.113274284 +0200
> @@ -1,10 +1,10 @@
>  The following options are target specific:
>    -mabi=ABI                   		lp64
> -  -march=ARCH                 		
> +  -march=                     		armv8-a

So we have

    -mabi=ABI                   		lp64

but

    -march=                     		armv8-a
           ^^^^^ blank

Isn't that inconsistent?

R.

>    -mbig-endian                		[disabled]
>    -mbionic                    		[disabled]
>    -mcmodel=                   		small
> -  -mcpu=CPU                   		
> +  -mcpu=                      		generic
>    -mfix-cortex-a53-835769     		[enabled]
>    -mfix-cortex-a53-843419     		[enabled]
>    -mgeneral-regs-only         		[disabled]
> @@ -19,7 +19,7 @@
>    -msve-vector-bits=N         		scalable
>    -mtls-dialect=              		desc
>    -mtls-size=                 		24
> -  -mtune=CPU                  		
> +  -mtune=                     		generic
>    -muclibc                    		[disabled]
> 
> May I please ask ARM folks to test the patch?
> Thanks,
> Martin
> 
> gcc/ChangeLog:
> 
> 2018-07-18  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.
> ---
>  gcc/config/aarch64/aarch64.c   | 7 +++++++
>  gcc/config/aarch64/aarch64.opt | 6 +++---
>  2 files changed, 10 insertions(+), 3 deletions(-)
> 
> 
> 
> 0001-Print-default-options-selection-for-march-mcpu-and-m.patch
> 
> 
> diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
> index 6fa03e4b091..d48e6278efa 100644
> --- a/gcc/config/aarch64/aarch64.c
> +++ b/gcc/config/aarch64/aarch64.c
> @@ -10713,6 +10713,13 @@ 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);
>  }
>  
> diff --git a/gcc/config/aarch64/aarch64.opt b/gcc/config/aarch64/aarch64.opt
> index 1426b45ff0f..7f0b65de37b 100644
> --- a/gcc/config/aarch64/aarch64.opt
> +++ b/gcc/config/aarch64/aarch64.opt
> @@ -117,15 +117,15 @@ 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)
>