On 08/02/2018 11:39 AM, Richard Earnshaw (lists) wrote:
> 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?
It is probably, in this case I would remove 'ABI' from -mabi option. It's
explained bellow
what are possible options:
Known AArch64 ABIs (for use with the -mabi= option):
ilp32 lp64
Similarly for:
-moverride=STRING Power users only! Override CPU optimization
parameters.
-msve-vector-bits=N Set the number of bits in an SVE vector register
to N.
It's more common to <var> notation, there are some samples from --help=common:
-fmax-errors=<number> Maximum number of errors to report.
-fmessage-length=<number> Limit diagnostics to <number> characters per
line. 0 suppresses line-wrapping.
-fira-region=[one|all|mixed] Set regions for IRA.
-fira-verbose=<number> Control IRA's level of diagnostic messages.
-flifetime-dse=<0,2> This option lacks documentation.
-fstack-limit-register=<register> Trap if the stack goes past <register>.
-fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>.
Are you fine with the suggested approach?
Martin
>
> 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 <mli...@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)
>>
>
