Re: [PATCH, Pointer Bounds Checker 14/x] Passes [13/n] Optimize bounds intersections

[Jeff Law <law at redhat dot com>]

On 10/08/14 13:19, Ilya Enkovich wrote:
> Hi,
>
> This patch adds removal of unnecessary intersections into checker optimizations.
>
> Thanks,
> Ilya
> --
> 2014-10-08  Ilya Enkovich  <ilya.enkovich@intel.com>
>
> 	* tree-chkp.c (chkp_release_check_info): New.
> 	(chkp_init_check_info): New.
> 	(chkp_gather_checks_info): New.
> 	(chkp_get_check_result): New.
> 	(chkp_use_outer_bounds_if_possible): New.
> 	(chkp_remove_excess_intersections): New.
> 	(chkp_opt_execute): Run intersections removal
> 	algorithm.
Usual comment about basic tests and pulling the optimization work into 
its own file.


 +
> +/* Find all checks in current function and store info about them
> +   in check_infos.  */
> +void
> +chkp_gather_checks_info (void)
> +{
> +  basic_block bb;
> +  gimple_stmt_iterator i;
> +
> +  if (dump_file && (dump_flags & TDF_DETAILS))
> +    fprintf (dump_file, "Gathering information about checks...\n");
> +
> +  chkp_init_check_info ();
> +
> +  FOR_EACH_BB_FN (bb, cfun)
> +    {
> +      struct bb_checks *bbc = &check_infos[bb->index];
> +
> +      if (dump_file && (dump_flags & TDF_DETAILS))
> +	fprintf (dump_file, "Searching checks in BB%d...\n", bb->index);
> +
> +      for (i = gsi_start_bb (bb); !gsi_end_p (i); gsi_next (&i))
> +        {
> +	  gimple stmt = gsi_stmt (i);
> +
> +	  if (gimple_code (stmt) != GIMPLE_CALL)
> +	    continue;
> +
> +	  if (gimple_call_fndecl (stmt) == chkp_checkl_fndecl
> +	      || gimple_call_fndecl (stmt) == chkp_checku_fndecl)
> +	    {
> +	      struct check_info ci;
> +
> +	      chkp_fill_check_info (stmt, &ci);
> +	      bbc->checks.safe_push (ci);
> +
> +	      if (dump_file && (dump_flags & TDF_DETAILS))
> +		{
> +		  fprintf (dump_file, "Adding check information:\n");
> +		  fprintf (dump_file, "  bounds: ");
> +		  print_generic_expr (dump_file, ci.bounds, 0);
> +		  fprintf (dump_file, "\n  address: ");
> +		  chkp_print_addr (ci.addr);
> +		  fprintf (dump_file, "\n  check: ");
> +		  print_gimple_stmt (dump_file, stmt, 0, 0);
> +		}
> +	    }
> +	}
> +    }
> +}
So  I wonder if it makes sense to structure your optimization passes as:

gather_info
  opt1
  opt2
  opt3
  ...
release


The reason being it looks like you do a number of walks over the blocks 
and statements in the block to gather information.  ISTM you could do it 
once for all these optimizations and save youself some walking time.

This patch looks fine.

jeff