Re: [patch] Remove mw_link_pool

[Kenneth Zadeck <zadeck at naturalbridge dot com>]

Steven Bosscher wrote:
> Hi,
>
> This is dead/unused code in df-scan.c.  Multiword hardregs are not
> linked via df_links, so mw_link_pool is unused and the comment before
> struct df_lnk is incorrect.
>
> Bootstrapped&tested on x86_64-linux.
>
> Gr.
> Steven
>   
approved and committed by me as revision 136576.

2008-06-08  Steven Bosscher  <stevenb.gcc@gmail.com>

   * df-scan.c (struct df_scan_problem_data): Remove the
   mw_link_pool alloc pool.
   (df_scan_free_internal): Don't free it.
   (df_scan_alloc): Don't allocate it.
   * df.h (struct df_link): Update comment.

kenny
Index: df-scan.c
===================================================================
*** df-scan.c	(revision 136554)
--- df-scan.c	(working copy)
*************** struct df_scan_problem_data
*** 166,172 ****
    alloc_pool insn_pool;
    alloc_pool reg_pool;
    alloc_pool mw_reg_pool;
-   alloc_pool mw_link_pool;
    bitmap_obstack reg_bitmaps;
    bitmap_obstack insn_bitmaps;
  };
--- 166,171 ----
*************** df_scan_free_internal (void)
*** 221,227 ****
    free_alloc_pool (problem_data->insn_pool);
    free_alloc_pool (problem_data->reg_pool);
    free_alloc_pool (problem_data->mw_reg_pool);
-   free_alloc_pool (problem_data->mw_link_pool);
    bitmap_obstack_release (&problem_data->reg_bitmaps);
    bitmap_obstack_release (&problem_data->insn_bitmaps);
    free (df_scan->problem_data);
--- 220,225 ----
*************** df_scan_alloc (bitmap all_blocks ATTRIBU
*** 312,320 ****
    problem_data->mw_reg_pool 
      = create_alloc_pool ("df_scan_mw_reg pool", 
  			 sizeof (struct df_mw_hardreg), block_size);
-   problem_data->mw_link_pool 
-     = create_alloc_pool ("df_scan_mw_link pool", 
- 			 sizeof (struct df_link), block_size);
  
    bitmap_obstack_initialize (&problem_data->reg_bitmaps);
    bitmap_obstack_initialize (&problem_data->insn_bitmaps);
--- 310,315 ----
Index: df.h
===================================================================
*** df.h	(revision 136554)
--- df.h	(working copy)
*************** struct df_ref_extract
*** 409,417 ****
    enum machine_mode mode;
  };
  
! /* These links are used for two purposes:
!    1) def-use or use-def chains. 
!    2) Multiword hard registers that underly a single hardware register.  */
  struct df_link
  {
    struct df_ref *ref;
--- 409,416 ----
    enum machine_mode mode;
  };
  
! /* These links are used for ref-ref chains.  Currently only DEF-USE and
!    USE-DEF chains can be built by DF.  */
  struct df_link
  {
    struct df_ref *ref;