Re: Put scope blocks on a diet

[Diego Novillo <dnovillo@google.com>]

On 7/24/07 2:02 PM, Jan Hubicka wrote:

> 	* gimple-low.c (lower_stmt): When not doing debugging, don't save
> 	info about block.
> 	* tree-ssa-live.c: Include debug.h and flags.h.
> 	(mark_scope_block_unused): New function.
> 	(remove_unused_scope_block_p): New function.
> 	(remove_unused_locals): Remove unused blocks too.

OK with a few minor changes

> Index: gimple-low.c
> ===================================================================
> --- gimple-low.c	(revision 126859)
> +++ gimple-low.c	(working copy)
> @@ -210,7 +210,9 @@ lower_stmt (tree_stmt_iterator *tsi, str
>  {
>    tree stmt = tsi_stmt (*tsi);
>  
> -  if (EXPR_HAS_LOCATION (stmt) && data)
> +  if (EXPR_HAS_LOCATION (stmt) && data

&& data on the next line

>    tree t = *tp;
> +  char const c = TREE_CODE_CLASS (TREE_CODE (t));

Hmm?  TREE_CODE_CLASS is of type enum tree_code_class.

>  
> +/* Mark the scope block SCOPE and is subblocks unused when they can be

s/is/its/

> +
> +/* Look if the block is dead (by possibly elliminating it's dead subblocks)

s/elliminating/eliminating/
s/it's/its/

> +   and return true if so.  
> +   Block is declared dead if:
> +     1) No statements are associated with it.
> +     2) Declares no live variables
> +     3) All subblocks are dead
> +	or there is precisely one subblocks and the block
> +	has same abstract origin as outer block and declares
> +	no variables, so it is pure wrapper.
> +   When we are not outputting full debug info, we also elliminate dead variables
> +   out of scope blocks to let them to be recycled by GGC and to save copying work
> +   done by the inliner.
> +*/

Closing comment on previous line.

> +  mark_scope_block_unused (DECL_INITIAL (current_function_decl));

Comment before '/* Assume every block in the function is unused.  */'