Re: [PATCH] pass cleanups

[Richard Biener <rguenther at suse dot de>]

On Wed, 18 Jun 2014, Richard Biener wrote:

> 
> This removes the special dce_loop pass in favor of dealing with
> scev and niter estimates in dce generally.  Likewise it makes
> copyprop always cleanup after itself, dealing with scev and niter
> estimates.  It also makes copyprop not unconditionally schedule
> a cfg-cleanup but only do so if copyprop did any transform.
> 
> Bootstrap and regtest running on x86_64-unknown-linux-gnu.

I have applied the following with the testsuite adjustments needed
for gcc.dg/vect/dump-tree-dceloop-pr26359.c.

Richard.

2014-06-18  Richard Biener  <rguenther@suse.de>

	* tree-pass.h (make_pass_dce_loop): Remove.
	* passes.def: Replace pass_dce_loop with pass_dce.
	* tree-ssa-dce.c (perform_tree_ssa_dce): If something
	changed free niter estimates and reset the scev cache.
	(tree_ssa_dce_loop, pass_data_dce_loop, pass_dce_loop,
	make_pass_dce_loop): Remove.
	* tree-ssa-copy.c: Include tree-ssa-loop-niter.h.
	(fini_copy_prop): Return whether something changed.  Always
	let substitute_and_fold perform DCE and free niter estimates
	and reset the scev cache if so.
	(execute_copy_prop): If sth changed schedule cleanup-cfg.
	(pass_data_copy_prop): Do not unconditionally schedule
	cleanup-cfg or update-ssa.

	* gcc.dg/vect/vect.exp: Remove dump-tree-dceloop-* processing.
	* gcc.dg/vect/dump-tree-dceloop-pr26359.c: Rename to ...
	* gcc.dg/vect/pr26359.c: ... this and adjust appropriately.

Index: gcc/tree-pass.h
===================================================================
*** gcc/tree-pass.h	(revision 211738)
--- gcc/tree-pass.h	(working copy)
*************** extern gimple_opt_pass *make_pass_build_
*** 382,388 ****
  extern gimple_opt_pass *make_pass_build_ealias (gcc::context *ctxt);
  extern gimple_opt_pass *make_pass_dominator (gcc::context *ctxt);
  extern gimple_opt_pass *make_pass_dce (gcc::context *ctxt);
- extern gimple_opt_pass *make_pass_dce_loop (gcc::context *ctxt);
  extern gimple_opt_pass *make_pass_cd_dce (gcc::context *ctxt);
  extern gimple_opt_pass *make_pass_call_cdce (gcc::context *ctxt);
  extern gimple_opt_pass *make_pass_merge_phi (gcc::context *ctxt);
--- 382,387 ----
Index: gcc/passes.def
===================================================================
*** gcc/passes.def	(revision 211738)
--- gcc/passes.def	(working copy)
*************** along with GCC; see the file COPYING3.
*** 203,209 ****
  	  NEXT_PASS (pass_tree_loop_init);
  	  NEXT_PASS (pass_lim);
  	  NEXT_PASS (pass_copy_prop);
! 	  NEXT_PASS (pass_dce_loop);
  	  NEXT_PASS (pass_tree_unswitch);
  	  NEXT_PASS (pass_scev_cprop);
  	  NEXT_PASS (pass_record_bounds);
--- 206,212 ----
  	  NEXT_PASS (pass_tree_loop_init);
  	  NEXT_PASS (pass_lim);
  	  NEXT_PASS (pass_copy_prop);
! 	  NEXT_PASS (pass_dce);
  	  NEXT_PASS (pass_tree_unswitch);
  	  NEXT_PASS (pass_scev_cprop);
  	  NEXT_PASS (pass_record_bounds);
*************** along with GCC; see the file COPYING3.
*** 215,221 ****
  	      NEXT_PASS (pass_graphite_transforms);
  	      NEXT_PASS (pass_lim);
  	      NEXT_PASS (pass_copy_prop);
! 	      NEXT_PASS (pass_dce_loop);
  	  POP_INSERT_PASSES ()
  	  NEXT_PASS (pass_iv_canon);
  	  NEXT_PASS (pass_parallelize_loops);
--- 218,224 ----
  	      NEXT_PASS (pass_graphite_transforms);
  	      NEXT_PASS (pass_lim);
  	      NEXT_PASS (pass_copy_prop);
! 	      NEXT_PASS (pass_dce);
  	  POP_INSERT_PASSES ()
  	  NEXT_PASS (pass_iv_canon);
  	  NEXT_PASS (pass_parallelize_loops);
*************** along with GCC; see the file COPYING3.
*** 224,230 ****
  	     Please do not add any other passes in between.  */
  	  NEXT_PASS (pass_vectorize);
            PUSH_INSERT_PASSES_WITHIN (pass_vectorize)
! 	      NEXT_PASS (pass_dce_loop);
            POP_INSERT_PASSES ()
            NEXT_PASS (pass_predcom);
  	  NEXT_PASS (pass_complete_unroll);
--- 227,233 ----
  	     Please do not add any other passes in between.  */
  	  NEXT_PASS (pass_vectorize);
            PUSH_INSERT_PASSES_WITHIN (pass_vectorize)
! 	      NEXT_PASS (pass_dce);
            POP_INSERT_PASSES ()
            NEXT_PASS (pass_predcom);
  	  NEXT_PASS (pass_complete_unroll);
Index: gcc/tree-ssa-dce.c
===================================================================
*** gcc/tree-ssa-dce.c	(revision 211738)
--- gcc/tree-ssa-dce.c	(working copy)
*************** perform_tree_ssa_dce (bool aggressive)
*** 1479,1485 ****
    tree_dce_done (aggressive);
  
    if (something_changed)
!     return TODO_update_ssa | TODO_cleanup_cfg;
    return 0;
  }
  
--- 1479,1490 ----
    tree_dce_done (aggressive);
  
    if (something_changed)
!     {
!       free_numbers_of_iterations_estimates ();
!       if (scev_initialized_p)
! 	scev_reset ();
!       return TODO_update_ssa | TODO_cleanup_cfg;
!     }
    return 0;
  }
  
*************** tree_ssa_dce (void)
*** 1491,1509 ****
  }
  
  static unsigned int
- tree_ssa_dce_loop (void)
- {
-   unsigned int todo;
-   todo = perform_tree_ssa_dce (/*aggressive=*/false);
-   if (todo)
-     {
-       free_numbers_of_iterations_estimates ();
-       scev_reset ();
-     }
-   return todo;
- }
- 
- static unsigned int
  tree_ssa_cd_dce (void)
  {
    return perform_tree_ssa_dce (/*aggressive=*/optimize >= 2);
--- 1496,1501 ----
*************** make_pass_dce (gcc::context *ctxt)
*** 1548,1591 ****
  }
  
  namespace {
- 
- const pass_data pass_data_dce_loop =
- {
-   GIMPLE_PASS, /* type */
-   "dceloop", /* name */
-   OPTGROUP_NONE, /* optinfo_flags */
-   true, /* has_execute */
-   TV_TREE_DCE, /* tv_id */
-   ( PROP_cfg | PROP_ssa ), /* properties_required */
-   0, /* properties_provided */
-   0, /* properties_destroyed */
-   0, /* todo_flags_start */
-   0, /* todo_flags_finish */
- };
- 
- class pass_dce_loop : public gimple_opt_pass
- {
- public:
-   pass_dce_loop (gcc::context *ctxt)
-     : gimple_opt_pass (pass_data_dce_loop, ctxt)
-   {}
- 
-   /* opt_pass methods: */
-   opt_pass * clone () { return new pass_dce_loop (m_ctxt); }
-   virtual bool gate (function *) { return flag_tree_dce != 0; }
-   virtual unsigned int execute (function *) { return tree_ssa_dce_loop (); }
- 
- }; // class pass_dce_loop
- 
- } // anon namespace
- 
- gimple_opt_pass *
- make_pass_dce_loop (gcc::context *ctxt)
- {
-   return new pass_dce_loop (ctxt);
- }
- 
- namespace {
  
  const pass_data pass_data_cd_dce =
  {
--- 1540,1545 ----
Index: gcc/tree-ssa-copy.c
===================================================================
*** gcc/tree-ssa-copy.c	(revision 211738)
--- gcc/tree-ssa-copy.c	(working copy)
*************** along with GCC; see the file COPYING3.
*** 45,50 ****
--- 45,52 ----
  #include "cfgloop.h"
  #include "tree-scalar-evolution.h"
  #include "tree-ssa-dom.h"
+ #include "tree-ssa-loop-niter.h"
+ 
  
  /* This file implements the copy propagation pass and provides a
     handful of interfaces for performing const/copy propagation and
*************** get_value (tree name)
*** 542,548 ****
  /* Deallocate memory used in copy propagation and do final
     substitution.  */
  
! static void
  fini_copy_prop (void)
  {
    unsigned i;
--- 544,550 ----
  /* Deallocate memory used in copy propagation and do final
     substitution.  */
  
! static bool
  fini_copy_prop (void)
  {
    unsigned i;
*************** fini_copy_prop (void)
*** 594,603 ****
  	}
      }
  
!   /* Don't do DCE if SCEV is initialized.  It would destroy the scev cache.  */
!   substitute_and_fold (get_value, NULL, !scev_initialized_p ());
  
    free (copy_of);
  }
  
  
--- 596,612 ----
  	}
      }
  
!   bool changed = substitute_and_fold (get_value, NULL, true);
!   if (changed)
!     {
!       free_numbers_of_iterations_estimates ();
!       if (scev_initialized_p ())
! 	scev_reset ();
!     }
  
    free (copy_of);
+ 
+   return changed;
  }
  
  
*************** execute_copy_prop (void)
*** 639,645 ****
  {
    init_copy_prop ();
    ssa_propagate (copy_prop_visit_stmt, copy_prop_visit_phi_node);
!   fini_copy_prop ();
    return 0;
  }
  
--- 648,655 ----
  {
    init_copy_prop ();
    ssa_propagate (copy_prop_visit_stmt, copy_prop_visit_phi_node);
!   if (fini_copy_prop ())
!     return TODO_cleanup_cfg;
    return 0;
  }
  
*************** const pass_data pass_data_copy_prop =
*** 656,662 ****
    0, /* properties_provided */
    0, /* properties_destroyed */
    0, /* todo_flags_start */
!   ( TODO_cleanup_cfg | TODO_update_ssa ), /* todo_flags_finish */
  };
  
  class pass_copy_prop : public gimple_opt_pass
--- 666,672 ----
    0, /* properties_provided */
    0, /* properties_destroyed */
    0, /* todo_flags_start */
!   0, /* todo_flags_finish */
  };
  
  class pass_copy_prop : public gimple_opt_pass