Re: [dataflow][PATCH] Fix a regression on ia64 - subregs_of_mode cleanup

[Kenneth Zadeck <zadeck at naturalbridge dot com>]

Seongbae Park wrote:
> Hi,
>
ok to commit.

> This patch fixes a regression on ia64 which was due to
> subregs_of_mode not being up-to-date when used.
> Since I couldn't find any use of subregs_of_mode
> other than local and global allocs,
> I've moved subregs_of_mode_init just before local-alloc
> created a new subregs_of_mode_finish after global-alloc,
> and added extra assertions to make sure
> it is only used when valid,
> to prevent other passes from accidentally using it.
> Bootstrapped and regtested on ia64.
>
> 2007-03-13  Seongbae Park <seongbae.park@gmail.com>
>
>        * tree-pass.h (pass_subregs_of_mode_finish): New pass declaration.
>        * regclass.c (record_subregs_of_mode): Made static, and
>         moved before init_subregs_of_mode to compile.
>         (cannot_change_mode_set_regs, invalid_mode_change_p):
>         Added assertion.
>         (finish_subregs_of_mode): New function.
>         (pass_subregs_of_mode_finish): New pass.
>         * rtl.h (record_subregs_of_mode): Removed.
>         * combine.c (gen_lowpart_for_combine): Removed
>          calls to record_subregs_of_mode.
>         * passes.c (init_optimization_passes): Moved
> pass_subregs_of_mode_init
>           just before local_alloc. New pass pass_subregs_of_mode_finish
>           after global_alloc.
>
> ------------------------------------------------------------------------
>
> Index: tree-pass.h
> ===================================================================
> --- tree-pass.h	(revision 122890)
> +++ tree-pass.h	(working copy)
> @@ -370,6 +370,7 @@ extern struct tree_opt_pass pass_cse2;
>  extern struct tree_opt_pass pass_df_initialize;
>  extern struct tree_opt_pass pass_regclass_init;
>  extern struct tree_opt_pass pass_subregs_of_mode_init;
> +extern struct tree_opt_pass pass_subregs_of_mode_finish;
>  extern struct tree_opt_pass pass_inc_dec;
>  extern struct tree_opt_pass pass_no_new_pseudos;
>  extern struct tree_opt_pass pass_stack_ptr_mod;
> Index: regclass.c
> ===================================================================
> --- regclass.c	(revision 122890)
> +++ regclass.c	(working copy)
> @@ -2677,6 +2677,38 @@ som_eq (const void *x, const void *y)
>  }
>  
>  
> +static void
> +record_subregs_of_mode (rtx subreg)
> +{
> +  struct subregs_of_mode_node dummy, *node;
> +  enum machine_mode mode;
> +  unsigned int regno;
> +  void **slot;
> +
> +  if (!REG_P (SUBREG_REG (subreg)))
> +    return;
> +
> +  regno = REGNO (SUBREG_REG (subreg));
> +  mode = GET_MODE (subreg);
> +
> +  if (regno < FIRST_PSEUDO_REGISTER)
> +    return;
> +
> +  dummy.block = regno & -8;
> +  slot = htab_find_slot_with_hash (subregs_of_mode, &dummy,
> +				   dummy.block, INSERT);
> +  node = *slot;
> +  if (node == NULL)
> +    {
> +      node = XCNEW (struct subregs_of_mode_node);
> +      node->block = regno & -8;
> +      *slot = node;
> +    }
> +
> +  node->modes[mode] |= 1 << (regno & 7);
> +}
> +
> +
>  /* Call record_subregs_of_mode for all the subregs in X.  */
>  
>  static void 
> @@ -2722,36 +2754,6 @@ init_subregs_of_mode (void)
>    return 0;
>  }
>  
> -void
> -record_subregs_of_mode (rtx subreg)
> -{
> -  struct subregs_of_mode_node dummy, *node;
> -  enum machine_mode mode;
> -  unsigned int regno;
> -  void **slot;
> -
> -  if (!REG_P (SUBREG_REG (subreg)))
> -    return;
> -
> -  regno = REGNO (SUBREG_REG (subreg));
> -  mode = GET_MODE (subreg);
> -
> -  if (regno < FIRST_PSEUDO_REGISTER)
> -    return;
> -
> -  dummy.block = regno & -8;
> -  slot = htab_find_slot_with_hash (subregs_of_mode, &dummy,
> -				   dummy.block, INSERT);
> -  node = *slot;
> -  if (node == NULL)
> -    {
> -      node = XCNEW (struct subregs_of_mode_node);
> -      node->block = regno & -8;
> -      *slot = node;
> -    }
> -
> -  node->modes[mode] |= 1 << (regno & 7);
> -}
>  
>  /* Set bits in *USED which correspond to registers which can't change
>     their mode from FROM to any mode in which REGNO was encountered.  */
> @@ -2765,6 +2767,7 @@ cannot_change_mode_set_regs (HARD_REG_SE
>    unsigned char mask;
>    unsigned int i;
>  
> +  gcc_assert (subregs_of_mode);
>    dummy.block = regno & -8;
>    node = htab_find_with_hash (subregs_of_mode, &dummy, dummy.block);
>    if (node == NULL)
> @@ -2790,6 +2793,7 @@ invalid_mode_change_p (unsigned int regn
>    enum machine_mode to;
>    unsigned char mask;
>  
> +  gcc_assert (subregs_of_mode);
>    dummy.block = regno & -8;
>    node = htab_find_with_hash (subregs_of_mode, &dummy, dummy.block);
>    if (node == NULL)
> @@ -2803,12 +2807,25 @@ invalid_mode_change_p (unsigned int regn
>  
>    return false;
>  }
> +
> +static unsigned int
> +finish_subregs_of_mode (void)
> +{
> +  htab_delete (subregs_of_mode);
> +  subregs_of_mode = 0;
> +  return 0;
> +}
>  #else
>  static unsigned int
>  init_subregs_of_mode (void)
>  {
>    return 0;
>  }
> +static unsigned int
> +finish_subregs_of_mode (void)
> +{
> +  return 0;
> +}
>  
>  #endif /* CANNOT_CHANGE_MODE_CLASS */
>  
> @@ -2839,6 +2856,23 @@ struct tree_opt_pass pass_subregs_of_mod
>    0                                     /* letter */
>  };
>  
> +struct tree_opt_pass pass_subregs_of_mode_finish =
> +{
> +  "subregs_of_mode_finish",               /* name */
> +  gate_subregs_of_mode_init,            /* gate */
> +  finish_subregs_of_mode,               /* execute */
> +  NULL,                                 /* sub */
> +  NULL,                                 /* next */
> +  0,                                    /* static_pass_number */
> +  0,                                    /* tv_id */
> +  0,                                    /* properties_required */
> +  0,                                    /* properties_provided */
> +  0,                                    /* properties_destroyed */
> +  0,                                    /* todo_flags_start */
> +  0,                                    /* todo_flags_finish */
> +  0                                     /* letter */
> +};
> +
>  
>  
>  #include "gt-regclass.h"
> Index: rtl.h
> ===================================================================
> --- rtl.h	(revision 122890)
> +++ rtl.h	(working copy)
> @@ -2156,7 +2156,6 @@ extern void regclass (rtx, int);
>  extern void reg_scan (rtx, unsigned int);
>  extern void reg_scan_update (rtx, rtx, unsigned int);
>  extern void fix_register (const char *, int, int);
> -extern void record_subregs_of_mode (rtx);
>  #ifdef HARD_CONST
>  extern void cannot_change_mode_set_regs (HARD_REG_SET *,
>  					 enum machine_mode, unsigned int);
> Index: combine.c
> ===================================================================
>