Random cleanups [2/4]: canonicalize ctor values

[Richard Guenther]

On Thu, Mar 31, 2011 at 5:57 PM, Michael Matz <matz@suse.de> wrote:
> On Thu, 31 Mar 2011, Richard Guenther wrote:
>
>> > canonicalize_constructor_val may be doing useful things on ADDR_EXPR
>> > too, but you don't call it in that case because you only added your
>> > code in the default case.  You only reach it when the ADDR_EXPR is
>> > wrapped in a cast.
>> >
>> > Any reason why you didn't add it (possibly wrapped in a loop) _before_
>> > the switch statement?
>
> Nope, probably I didn't want to pay the cost each time, but you're right.
>
>> Indeed.  This comment needs adjustment, too:
>>
>>       /* We never have the chance to fixup types in global initializers
>>          during gimplification.  Do so here.  */
>
> Done in new patch.
>
>> as we now sort-of do this.  In fact it looks like all existing
>> canonicalize_constructor_val calls are subsumed by the lowering, so,
>> eventually remove those and move this function to a local place next to
>> its sole caller.
>
> Yeah.  I couldn't immediately convince myself that all simplifications
> will also be done on local vars (for which record_reference won't run), so
> I'll leave this for later (I'm for instance doubtful about the NULL return
> for when the current unit "can't" refer to a symbol).  FWIW I'm currently
> testing with these asserts which should tell me:
>
> -----------------------------------------------------
> @@ -152,7 +151,8 @@ get_symbol_constant_value (tree sym)
>       tree val = DECL_INITIAL (sym);
>       if (val)
>        {
> -         val = canonicalize_constructor_val (val);
> +         tree newval = canonicalize_constructor_val (val);
> +         gcc_assert (newval == val);
>          if (val && is_gimple_min_invariant (val))
>            return val;
>          else
> @@ -3164,7 +3164,11 @@ fold_ctor_reference (tree type, tree cto
>   /* We found the field with exact match.  */
>   if (useless_type_conversion_p (type, TREE_TYPE (ctor))
>       && !offset)
> -    return canonicalize_constructor_val (ctor);
> +    {
> +      tree newctor = canonicalize_constructor_val (ctor);
> +      gcc_assert (newctor == ctor);
> +      return newctor;
> +    }
>
>   /* We are at the end of walk, see if we can view convert the
>      result.  */
> @@ -3174,6 +3178,7 @@ fold_ctor_reference (tree type, tree cto
>                          TYPE_SIZE (TREE_TYPE (ctor)), 0))
>     {
>       ret = canonicalize_constructor_val (ctor);
> +      gcc_assert (ret == ctor);
>       ret = fold_unary (VIEW_CONVERT_EXPR, type, ret);
>       if (ret)
>        STRIP_NOPS (ret);
> -----------------------------------------------------
>
> In the meanwhile, is the below version okay?

If it bootstraps & tests ok then yes.  The java parts look obvious.

Thanks,
Richard.

>
> Ciao,
> Michael.
> --
>        * cgraphbuild.c (record_reference): Canonicalize constructor
>        values.
>        * gimple-fold.c (canonicalize_constructor_val): Accept being called
>        without function context.
>
> java/
>        * jcf-parse.c (java_emit_static_constructor): Clear cfun and
>        current_function_decl.
>
> Index: cgraphbuild.c
> ===================================================================
> --- cgraphbuild.c.orig  2011-03-29 17:08:15.000000000 +0200
> +++ cgraphbuild.c       2011-03-31 17:43:29.000000000 +0200
> @@ -53,6 +53,12 @@ record_reference (tree *tp, int *walk_su
>   tree decl;
>   struct record_reference_ctx *ctx = (struct record_reference_ctx *)data;
>
> +  t = canonicalize_constructor_val (t);
> +  if (!t)
> +    t = *tp;
> +  else if (t != *tp)
> +    *tp = t;
> +
>   switch (TREE_CODE (t))
>     {
>     case VAR_DECL:
> Index: gimple-fold.c
> ===================================================================
> --- gimple-fold.c.orig  2011-03-29 17:08:15.000000000 +0200
> +++ gimple-fold.c       2011-03-31 17:42:45.000000000 +0200
> @@ -106,7 +106,7 @@ can_refer_decl_in_current_unit_p (tree d
>   return true;
>  }
>
> -/* CVAL is value taken from DECL_INITIAL of variable.  Try to transorm it into
> +/* CVAL is value taken from DECL_INITIAL of variable.  Try to transform it into
>    acceptable form for is_gimple_min_invariant.   */
>
>  tree
> @@ -131,10 +131,9 @@ canonicalize_constructor_val (tree cval)
>              || TREE_CODE (base) == FUNCTION_DECL)
>          && !can_refer_decl_in_current_unit_p (base))
>        return NULL_TREE;
> -      if (base && TREE_CODE (base) == VAR_DECL)
> +      if (cfun && base && TREE_CODE (base) == VAR_DECL)
>        add_referenced_var (base);
> -      /* We never have the chance to fixup types in global initializers
> -         during gimplification.  Do so here.  */
> +      /* Fixup types in global initializers.  */
>       if (TREE_TYPE (TREE_TYPE (cval)) != TREE_TYPE (TREE_OPERAND (cval, 0)))
>        cval = build_fold_addr_expr (TREE_OPERAND (cval, 0));
>     }
> Index: java/jcf-parse.c
> ===================================================================
> --- java/jcf-parse.c.orig       2011-03-29 17:08:15.000000000 +0200
> +++ java/jcf-parse.c    2011-03-29 17:12:05.000000000 +0200
> @@ -1725,6 +1725,8 @@ java_emit_static_constructor (void)
>       DECL_STATIC_CONSTRUCTOR (decl) = 1;
>       java_genericize (decl);
>       cgraph_finalize_function (decl, false);
> +      current_function_decl = NULL;
> +      set_cfun (NULL);
>     }
>  }
>