2007-09-20  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/33508
	* tree-ssa-alias.c (mark_aliases_call_clobbered): Avoid
	quadratic loop by keeping a bitmap of variables we have
	to clobber all subvariables for.
	(set_initial_properties): Likewise.

Index: tree-ssa-alias.c
===================================================================
*** tree-ssa-alias.c	(revision 128618)
--- tree-ssa-alias.c	(working copy)
*************** mark_aliases_call_clobbered (tree tag, V
*** 366,372 ****
  			     VEC (int, heap) **worklist2,
  			     bitmap on_worklist)
  {
!   bitmap aliases;
    bitmap_iterator bi;
    unsigned int i;
    tree entry;
--- 366,372 ----
  			     VEC (int, heap) **worklist2,
  			     bitmap on_worklist)
  {
!   bitmap aliases, queued;
    bitmap_iterator bi;
    unsigned int i;
    tree entry;
*************** mark_aliases_call_clobbered (tree tag, V
*** 378,383 ****
--- 378,384 ----
    if (!aliases)
      return;
  
+   queued = BITMAP_ALLOC (&alias_bitmap_obstack);
    EXECUTE_IF_SET_IN_BITMAP (aliases, 0, i, bi)
      {
        entry = referenced_var (i);
*************** mark_aliases_call_clobbered (tree tag, V
*** 387,399 ****
  	 in order to allow C/C++ tricks that involve
  	 pointer arithmetic to work.  */
        if (TREE_CODE (entry) == STRUCT_FIELD_TAG)
! 	{
! 	  subvar_t svars;
! 	  svars = get_subvars_for_var (SFT_PARENT_VAR (entry));
! 	  for (; svars; svars = svars->next)
! 	    if (!unmodifiable_var_p (entry))
! 	      mark_call_clobbered (svars->var, ta->escape_mask);
! 	}
        else if (!unmodifiable_var_p (entry))
  	{
  	  add_to_worklist (entry, worklist, worklist2, ta->escape_mask,
--- 388,394 ----
  	 in order to allow C/C++ tricks that involve
  	 pointer arithmetic to work.  */
        if (TREE_CODE (entry) == STRUCT_FIELD_TAG)
! 	bitmap_set_bit (queued, DECL_UID (SFT_PARENT_VAR (entry)));
        else if (!unmodifiable_var_p (entry))
  	{
  	  add_to_worklist (entry, worklist, worklist2, ta->escape_mask,
*************** mark_aliases_call_clobbered (tree tag, V
*** 401,406 ****
--- 396,410 ----
  	  mark_call_clobbered (entry, ta->escape_mask);
  	}
      }
+   EXECUTE_IF_SET_IN_BITMAP (queued, 0, i, bi)
+     {
+       subvar_t svars;
+       svars = get_subvars_for_var (referenced_var (i));
+       for (; svars; svars = svars->next)
+ 	if (!unmodifiable_var_p (svars->var))
+ 	  mark_call_clobbered (svars->var, ta->escape_mask);
+     }
+   BITMAP_FREE (queued);
  }
  
  /* Tags containing global vars need to be marked as global.
*************** set_initial_properties (struct alias_inf
*** 545,552 ****
--- 549,558 ----
  
  	  if (pi->pt_vars)
  	    {
+ 	      bitmap queued;
  	      bitmap_iterator bi;
  	      unsigned int j;	      
+ 	      queued = BITMAP_ALLOC (&alias_bitmap_obstack);
  	      EXECUTE_IF_SET_IN_BITMAP (pi->pt_vars, 0, j, bi)
  		{
  		  tree alias = referenced_var (j);
*************** set_initial_properties (struct alias_inf
*** 557,572 ****
  		     in order to allow C/C++ tricks that involve
  		     pointer arithmetic to work.  */
  		  if (TREE_CODE (alias) == STRUCT_FIELD_TAG)
! 		    {
! 		      subvar_t svars;
! 		      svars = get_subvars_for_var (SFT_PARENT_VAR (alias));
! 		      for (; svars; svars = svars->next)
! 			if (!unmodifiable_var_p (alias))
! 			  mark_call_clobbered (svars->var, pi->escape_mask);
! 		    }
  		  else if (!unmodifiable_var_p (alias))
  		    mark_call_clobbered (alias, pi->escape_mask);
  		}
  	    }
  	}
  
--- 563,581 ----
  		     in order to allow C/C++ tricks that involve
  		     pointer arithmetic to work.  */
  		  if (TREE_CODE (alias) == STRUCT_FIELD_TAG)
! 		    bitmap_set_bit (queued, DECL_UID (SFT_PARENT_VAR (alias)));
  		  else if (!unmodifiable_var_p (alias))
  		    mark_call_clobbered (alias, pi->escape_mask);
  		}
+ 	      EXECUTE_IF_SET_IN_BITMAP (queued, 0, j, bi)
+ 		{
+ 		  subvar_t svars;
+ 		  svars = get_subvars_for_var (referenced_var (j));
+ 		  for (; svars; svars = svars->next)
+ 		    if (!unmodifiable_var_p (svars->var))
+ 		      mark_call_clobbered (svars->var, pi->escape_mask);
+ 		}
+ 	      BITMAP_FREE (queued);
  	    }
  	}