Re: [PR64164] drop copyrename, integrate into expand

[Richard Biener <richard.guenther@gmail.com>]

On Sat, Jul 18, 2015 at 9:37 AM, Alexandre Oliva <aoliva@redhat.com> wrote:
> On Jul 16, 2015, Alexandre Oliva <aoliva@redhat.com> wrote:
>
>> So, I decided to run a ppc64le-linux-gnu bootstrap, just in case, and
>> there are issues with split complex parms that caused go and fortran
>> libs to fail the build.
>
> This incremental patch, along with the previously-posted patches, fix
> split complex args handling with preassigned args RTL, and enables
> ppc64le-linux-gnu bootstrap to succeed.
>
> I'm not particularly happy with the abuse of DECL_CONTEXT to recognize
> split complex args and leave their RTL alone, but that was the best that
> occurred to me.  Any other suggestions?
>
> Is the combined patch ok, assuming further (re)testing of embedded
> targets passes?
>
> for  gcc/ChangeLog (to be integrated with the approved patches)
>
>         * function.c (split_complex_args): Take assign_parm_data_all
>         argument.  Pass it to rtl_for_parm.  Set up rtl and context
>         for split args.
>         (assign_parms_augmented_arg_list): Adjust.
>         (maybe_reset_rtl_for_parm): Recognize split complex args.
>         * stor-layout.c (layout_decl): Don't set mem attributes of
>         non-MEMs.
> ---
>  gcc/function.c    |   39 +++++++++++++++++++++++++++++++++++++--
>  gcc/stor-layout.c |    3 ++-
>  2 files changed, 39 insertions(+), 3 deletions(-)
>
> diff --git a/gcc/function.c b/gcc/function.c
> index 753d889..6fba001 100644
> --- a/gcc/function.c
> +++ b/gcc/function.c
> @@ -151,6 +151,8 @@ static bool contains (const_rtx, hash_table<insn_cache_hasher> *);
>  static void prepare_function_start (void);
>  static void do_clobber_return_reg (rtx, void *);
>  static void do_use_return_reg (rtx, void *);
> +static rtx rtl_for_parm (struct assign_parm_data_all *, tree);
> +
>
>  /* Stack of nested functions.  */
>  /* Keep track of the cfun stack.  */
> @@ -2267,7 +2269,7 @@ assign_parms_initialize_all (struct assign_parm_data_all *all)
>     needed, else the old list.  */
>
>  static void
> -split_complex_args (vec<tree> *args)
> +split_complex_args (struct assign_parm_data_all *all, vec<tree> *args)
>  {
>    unsigned i;
>    tree p;
> @@ -2278,6 +2280,7 @@ split_complex_args (vec<tree> *args)
>        if (TREE_CODE (type) == COMPLEX_TYPE
>           && targetm.calls.split_complex_arg (type))
>         {
> +         tree cparm = p;
>           tree decl;
>           tree subtype = TREE_TYPE (type);
>           bool addressable = TREE_ADDRESSABLE (p);
> @@ -2296,6 +2299,9 @@ split_complex_args (vec<tree> *args)
>           DECL_ARTIFICIAL (p) = addressable;
>           DECL_IGNORED_P (p) = addressable;
>           TREE_ADDRESSABLE (p) = 0;
> +         /* Reset the RTL before layout_decl, or it may change the
> +            mode of the RTL of the original argument copied to P.  */
> +         SET_DECL_RTL (p, NULL_RTX);
>           layout_decl (p, 0);
>           (*args)[i] = p;
>
> @@ -2307,6 +2313,25 @@ split_complex_args (vec<tree> *args)
>           DECL_IGNORED_P (decl) = addressable;
>           layout_decl (decl, 0);
>           args->safe_insert (++i, decl);
> +
> +         /* If we are assigning parameters for a function, rather
> +            than for a call, propagate the RTL of the complex parm to
> +            the split declarations, and set their contexts so that
> +            maybe_reset_rtl_for_parm can recognize them and refrain
> +            from resetting their RTL.  */
> +         if (cfun->gimple_df)

If the cfun->gimple_df check is to decide whether this is a call or a function
then no, this can't work reliably.  What is this test for else?

You pass another argument to split_complex_arg, so why not pass in a bool
on whether we split it for this or the other case?

Richard.

> +           {
> +             rtx rtl = rtl_for_parm (all, cparm);
> +             gcc_assert (!rtl || GET_CODE (rtl) == CONCAT);
> +             if (rtl)
> +               {
> +                 SET_DECL_RTL (p, XEXP (rtl, 0));
> +                 SET_DECL_RTL (decl, XEXP (rtl, 1));
> +
> +                 DECL_CONTEXT (p) = cparm;
> +                 DECL_CONTEXT (decl) = cparm;
> +               }
> +           }
>         }
>      }
>  }
> @@ -2369,7 +2394,7 @@ assign_parms_augmented_arg_list (struct assign_parm_data_all *all)
>
>    /* If the target wants to split complex arguments into scalars, do so.  */
>    if (targetm.calls.split_complex_arg)
> -    split_complex_args (&fnargs);
> +    split_complex_args (all, &fnargs);
>
>    return fnargs;
>  }
> @@ -2823,6 +2848,16 @@ maybe_reset_rtl_for_parm (tree parm)
>  {
>    gcc_assert (TREE_CODE (parm) == PARM_DECL
>               || TREE_CODE (parm) == RESULT_DECL);
> +
> +  /* This is a split complex parameter, and its context was set to its
> +     original PARM_DECL in split_complex_args so that we could
> +     recognize it here and not reset its RTL.  */
> +  if (DECL_CONTEXT (parm) && TREE_CODE (DECL_CONTEXT (parm)) == PARM_DECL)
> +    {
> +      DECL_CONTEXT (parm) = DECL_CONTEXT (DECL_CONTEXT (parm));
> +      return;
> +    }
> +
>    if ((flag_tree_coalesce_vars
>         || (DECL_RTL_SET_P (parm) && DECL_RTL (parm) == pc_rtx))
>        && is_gimple_reg (parm))
> diff --git a/gcc/stor-layout.c b/gcc/stor-layout.c
> index 0d4f4a4..288227a 100644
> --- a/gcc/stor-layout.c
> +++ b/gcc/stor-layout.c
> @@ -794,7 +794,8 @@ layout_decl (tree decl, unsigned int known_align)
>      {
>        PUT_MODE (rtl, DECL_MODE (decl));
>        SET_DECL_RTL (decl, 0);
> -      set_mem_attributes (rtl, decl, 1);
> +      if (MEM_P (rtl))
> +       set_mem_attributes (rtl, decl, 1);
>        SET_DECL_RTL (decl, rtl);
>      }
>  }
>
>
> --
> Alexandre Oliva, freedom fighter    http://FSFLA.org/~lxoliva/
> You must be the change you wish to see in the world. -- Gandhi
> Be Free! -- http://FSFLA.org/   FSF Latin America board member
> Free Software Evangelist|Red Hat Brasil GNU Toolchain Engineer