Re: [PATCH] calls: Fix up TYPE_NO_NAMED_ARGS_STDARG_P handling [PR107453]

[Richard Biener <rguenther@suse.de>]

On Mon, 9 Jan 2023, Jakub Jelinek wrote:

> Hi!
> 
> On powerpc64le-linux, the following patch fixes
> -FAIL: gcc.dg/c2x-stdarg-4.c execution test
> -FAIL: gcc.dg/torture/c2x-stdarg-split-1a.c   -O0  execution test
> -FAIL: gcc.dg/torture/c2x-stdarg-split-1a.c   -O1  execution test
> -FAIL: gcc.dg/torture/c2x-stdarg-split-1a.c   -O2  execution test
> -FAIL: gcc.dg/torture/c2x-stdarg-split-1a.c   -O2 -flto -fno-use-linker-plugin -flto-partition=none  execution test
> -FAIL: gcc.dg/torture/c2x-stdarg-split-1a.c   -O2 -flto -fuse-linker-plugin -fno-fat-lto-objects  execution test
> -FAIL: gcc.dg/torture/c2x-stdarg-split-1a.c   -O3 -g  execution test
> -FAIL: gcc.dg/torture/c2x-stdarg-split-1a.c   -Os  execution test
> The problem is mismatch between the caller and callee side.
> On the callee side, we do:
>   /* NAMED_ARG is a misnomer.  We really mean 'non-variadic'. */
>   if (!cfun->stdarg)
>     data->arg.named = 1;  /* No variadic parms.  */
>   else if (DECL_CHAIN (parm))
>     data->arg.named = 1;  /* Not the last non-variadic parm. */
>   else if (targetm.calls.strict_argument_naming (all->args_so_far))
>     data->arg.named = 1;  /* Only variadic ones are unnamed.  */
>   else
>     data->arg.named = 0;  /* Treat as variadic.  */
> which is later passed to the target hooks to determine if a particular
> argument is named or not.  Now, cfun->stdarg is determined from the stdarg_p
> call, which for the new C2X TYPE_NO_NAMED_ARGS_STDARG_P function types
> (rettype fn (...)) returns true.  Such functions have no named arguments,
> so data->arg.named will be 0 in function.cc.  But on the caller side,
> as TYPE_NO_NAMED_ARGS_STDARG_P function types have TYPE_ARG_TYPES NULL,
> we instead treat those calls as unprototyped even when they are prototyped
> - /* If we know nothing, treat all args as named.  */ n_named_args = num_actuals;
> in 2 spots.  We need to treat the TYPE_NO_NAMED_ARGS_STDARG_P cases as
> prototyped with no named arguments.
> 
> Bootstrapped/regtested on x86_64-linux, i686-linux, powerpc64le-linux (where
> it fixes the above failures), aarch64-linux and s390x-linux, ok for trunk?

LGTM.

Richard.

> 2023-01-09  Jakub Jelinek  <jakub@redhat.com>
> 
> 	PR target/107453
> 	* calls.cc (expand_call): For calls with
> 	TYPE_NO_NAMED_ARGS_STDARG_P (funtype) use zero for n_named_args.
> 	Formatting fix.
> 
> --- gcc/calls.cc.jj	2023-01-02 09:32:28.834192105 +0100
> +++ gcc/calls.cc	2023-01-06 14:52:14.740594896 +0100
> @@ -2908,8 +2908,8 @@ expand_call (tree exp, rtx target, int i
>      }
>  
>    /* Count the arguments and set NUM_ACTUALS.  */
> -  num_actuals =
> -    call_expr_nargs (exp) + num_complex_actuals + structure_value_addr_parm;
> +  num_actuals
> +    = call_expr_nargs (exp) + num_complex_actuals + structure_value_addr_parm;
>  
>    /* Compute number of named args.
>       First, do a raw count of the args for INIT_CUMULATIVE_ARGS.  */
> @@ -2919,6 +2919,8 @@ expand_call (tree exp, rtx target, int i
>        = (list_length (type_arg_types)
>  	 /* Count the struct value address, if it is passed as a parm.  */
>  	 + structure_value_addr_parm);
> +  else if (TYPE_NO_NAMED_ARGS_STDARG_P (funtype))
> +    n_named_args = 0;
>    else
>      /* If we know nothing, treat all args as named.  */
>      n_named_args = num_actuals;
> @@ -2957,6 +2959,8 @@ expand_call (tree exp, rtx target, int i
>  	   && ! targetm.calls.pretend_outgoing_varargs_named (args_so_far))
>      /* Don't include the last named arg.  */
>      --n_named_args;
> +  else if (TYPE_NO_NAMED_ARGS_STDARG_P (funtype))
> +    n_named_args = 0;
>    else
>      /* Treat all args as named.  */
>      n_named_args = num_actuals;
> 
> 	Jakub
> 
> 

-- 
Richard Biener <rguenther@suse.de>
SUSE Software Solutions Germany GmbH, Frankenstrasse 146, 90461 Nuernberg,
Germany; GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman;
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