Re: [PATCH] flag_complex_method: support optimize attribute

[Jeff Law <jeffreyalaw@gmail.com>]

On 9/7/2021 3:42 AM, Martin Liška wrote:
> On 9/6/21 14:16, Richard Biener wrote:
>> On Mon, Sep 6, 2021 at 1:46 PM Jakub Jelinek <jakub@redhat.com> wrote:
>>>
>>> On Mon, Sep 06, 2021 at 01:37:46PM +0200, Martin Liška wrote:
>>>> --- a/gcc/opts.c
>>>> +++ b/gcc/opts.c
>>>> @@ -1323,6 +1323,14 @@ finish_options (struct gcc_options *opts, 
>>>> struct gcc_options *opts_set,
>>>>         = (opts->x_flag_unroll_loops
>>>>            || opts->x_flag_peel_loops
>>>>            || opts->x_optimize >= 3);
>>>> +
>>>> +  /* With -fcx-limited-range, we do cheap and quick complex 
>>>> arithmetic.  */
>>>> +  if (opts->x_flag_cx_limited_range)
>>>> +    flag_complex_method = 0;
>>>> +
>>>> +  /* With -fcx-fortran-rules, we do something in-between cheap and 
>>>> C99.  */
>>>> +  if (opts->x_flag_cx_fortran_rules)
>>>> +    flag_complex_method = 1;
>>>
>>> That should then be opts->x_flag_complex_method instead of 
>>> flag_complex_method.
>>>
>>> Ok with that change.
>>
>> But the C/C++ langhooks also set flag_complex_method so I fail to see 
>> how
>> this helps?  As said I was referring to -fcx-limited-range on the 
>> command-line
>> and -fno-cx-limited-range in the optimize node to undo this which should
>> get you the langhook setting of flag_complex_method = 2.
>
> You are right, it's even more complicated as -fno-cx-limited-range is 
> target specific.
> Option handling has been introducing surprises every time ...
>
> The following tested patch should handle it.
>
> Ready to be installed?
> Thanks,
> Martin
>
>>
>>> Note, I think we want to do much more in finish_options and less in
>>> process_options, anything that is about Optimization options rather 
>>> than
>>> just the global ones.  Though one needs to be careful with the cases 
>>> where
>>> the code diagnoses something.
>>>
>>>          Jakub
>>>
>
> 0001-flag_complex_method-support-optimize-attribute.patch
>
>  From e88ae14be7c5609a969897b5d09f40709fea8a34 Mon Sep 17 00:00:00 2001
> From: Martin Liska <mliska@suse.cz>
> Date: Fri, 3 Sep 2021 10:53:00 +0200
> Subject: [PATCH] flag_complex_method: support optimize attribute
>
> gcc/c-family/ChangeLog:
>
> 	* c-opts.c (c_common_init_options_struct): Set also
> 	  x_flag_default_complex_method.
>
> gcc/ChangeLog:
>
> 	* common.opt: Add new variable flag_default_complex_method.
> 	* opts.c (finish_options): Handle flags related to
> 	  x_flag_complex_method.
> 	* toplev.c (process_options): Remove option handling related
> 	to flag_complex_method.
>
> gcc/go/ChangeLog:
>
> 	* go-lang.c (go_langhook_init_options_struct): Set also
> 	  x_flag_default_complex_method.
>
> gcc/lto/ChangeLog:
>
> 	* lto-lang.c (lto_init_options_struct): Set also
> 	  x_flag_default_complex_method.
>
> gcc/testsuite/ChangeLog:
>
> 	* gcc.c-torture/compile/attr-complex-method-2.c: New test.
> 	* gcc.c-torture/compile/attr-complex-method.c: New test.
OK
jeff