tree-scalar-evolution.h (final_value_replacement_loop): Update prototype.

2018-11-05  Richard Biener  <rguenther@suse.de>

	* tree-scalar-evolution.h (final_value_replacement_loop): Update
	prototype.
	* tree-scalar-evolution.c (final_value_replacement_loop): Return
	whether anything was done.
	(scev_const_prop): Remove constant propagation part, fold
	remains into ...
	* tree-ssa-loop.c (pass_scev_cprop::execute): ... here.
	(pass_data_scev_cprop): TODO_cleanup_cfg is now done
	conditionally.

	* gcc.dg/pr41488.c: Scan ivcanon dump instead of sccp one.
	* gcc.dg/tree-ssa/scev-7.c: Likewise.

From-SVN: r265795

gcc/ChangeLog

+2018-11-05  Richard Biener  <rguenther@suse.de>
+
+	* tree-scalar-evolution.h (final_value_replacement_loop): Update
+	prototype.
+	* tree-scalar-evolution.c (final_value_replacement_loop): Return
+	whether anything was done.
+	(scev_const_prop): Remove constant propagation part, fold
+	remains into ...
+	* tree-ssa-loop.c (pass_scev_cprop::execute): ... here.
+	(pass_data_scev_cprop): TODO_cleanup_cfg is now done
+	conditionally.
+
 2018-11-05  Jakub Jelinek  <jakub@redhat.com>
 
 	PR tree-optimization/87859

gcc/testsuite/ChangeLog

+2018-11-05  Richard Biener  <rguenther@suse.de>
+
+	* gcc.dg/pr41488.c: Scan ivcanon dump instead of sccp one.
+	* gcc.dg/tree-ssa/scev-7.c: Likewise.
+
 2018-11-05  Jakub Jelinek  <jakub@redhat.com>
 
 	PR tree-optimization/87859

gcc/testsuite/gcc.dg/pr41488.c

 /* { dg-do compile } */
-/* { dg-options "-O2 -fdump-tree-sccp-scev" } */
+/* { dg-options "-O2 -fdump-tree-ivcanon-scev" } */
 
 struct struct_t
 {
@@ -14,4 +14,4 @@ void foo (struct struct_t* sp, int start, int end)
     sp->data[i+start] = 0;
 }
 
-/* { dg-final { scan-tree-dump-times "Simplify PEELED_CHREC into POLYNOMIAL_CHREC" 1 "sccp" } } */
+/* { dg-final { scan-tree-dump-times "Simplify PEELED_CHREC into POLYNOMIAL_CHREC" 1 "ivcanon" } } */

gcc/testsuite/gcc.dg/tree-ssa/scev-7.c

 /* { dg-do compile } */
-/* { dg-options "-O2 -fdump-tree-sccp-scev" } */
+/* { dg-options "-O2 -fdump-tree-ivcanon-scev" } */
 
 struct struct_t
 {
@@ -14,4 +14,4 @@ void foo (struct struct_t* sp, int start, int end)
     sp->data[i+start] = 0;
 }
 
-/* { dg-final { scan-tree-dump-times "Simplify PEELED_CHREC into POLYNOMIAL_CHREC" 1 "sccp" } } */
+/* { dg-final { scan-tree-dump-times "Simplify PEELED_CHREC into POLYNOMIAL_CHREC" 1 "ivcanon" } } */

gcc/tree-scalar-evolution.c

@@ -3537,20 +3537,20 @@ expression_expensive_p (tree expr)
     }
 }
 
-/* Do final value replacement for LOOP.  */
+/* Do final value replacement for LOOP, return true if we did anything.  */
 
-void
+bool
 final_value_replacement_loop (struct loop *loop)
 {
   /* If we do not know exact number of iterations of the loop, we cannot
      replace the final value.  */
   edge exit = single_exit (loop);
   if (!exit)
-    return;
+    return false;
 
   tree niter = number_of_latch_executions (loop);
   if (niter == chrec_dont_know)
-    return;
+    return false;
 
   /* Ensure that it is possible to insert new statements somewhere.  */
   if (!single_pred_p (exit->dest))
@@ -3563,6 +3563,7 @@ final_value_replacement_loop (struct loop *loop)
     = superloop_at_depth (loop,
 			  loop_depth (exit->dest->loop_father) + 1);
 
+  bool any = false;
   gphi_iterator psi;
   for (psi = gsi_start_phis (exit->dest); !gsi_end_p (psi); )
     {
@@ -3620,6 +3621,7 @@ final_value_replacement_loop (struct loop *loop)
 	  fprintf (dump_file, " with expr: ");
 	  print_generic_expr (dump_file, def);
 	}
+      any = true;
       def = unshare_expr (def);
       remove_phi_node (&psi, false);
 
@@ -3662,100 +3664,8 @@ final_value_replacement_loop (struct loop *loop)
 	  fprintf (dump_file, "\n");
 	}
     }
-}
-
-/* Replace ssa names for that scev can prove they are constant by the
-   appropriate constants.  Also perform final value replacement in loops,
-   in case the replacement expressions are cheap.
-
-   We only consider SSA names defined by phi nodes; rest is left to the
-   ordinary constant propagation pass.  */
-
-unsigned int
-scev_const_prop (void)
-{
-  basic_block bb;
-  tree name, type, ev;
-  gphi *phi;
-  struct loop *loop;
-  bitmap ssa_names_to_remove = NULL;
-  unsigned i;
-  gphi_iterator psi;
-
-  if (number_of_loops (cfun) <= 1)
-    return 0;
-
-  FOR_EACH_BB_FN (bb, cfun)
-    {
-      loop = bb->loop_father;
-
-      for (psi = gsi_start_phis (bb); !gsi_end_p (psi); gsi_next (&psi))
-	{
-	  phi = psi.phi ();
-	  name = PHI_RESULT (phi);
-
-	  if (virtual_operand_p (name))
-	    continue;
-
-	  type = TREE_TYPE (name);
-
-	  if (!POINTER_TYPE_P (type)
-	      && !INTEGRAL_TYPE_P (type))
-	    continue;
-
-	  ev = resolve_mixers (loop, analyze_scalar_evolution (loop, name),
-			       NULL);
-	  if (!is_gimple_min_invariant (ev)
-	      || !may_propagate_copy (name, ev))
-	    continue;
-
-	  /* Replace the uses of the name.  */
-	  if (name != ev)
-	    {
-	      if (dump_file && (dump_flags & TDF_DETAILS))
-		{
-		  fprintf (dump_file, "Replacing uses of: ");
-		  print_generic_expr (dump_file, name);
-		  fprintf (dump_file, " with: ");
-		  print_generic_expr (dump_file, ev);
-		  fprintf (dump_file, "\n");
-		}
-	      replace_uses_by (name, ev);
-	    }
-
-	  if (!ssa_names_to_remove)
-	    ssa_names_to_remove = BITMAP_ALLOC (NULL);
-	  bitmap_set_bit (ssa_names_to_remove, SSA_NAME_VERSION (name));
-	}
-    }
-
-  /* Remove the ssa names that were replaced by constants.  We do not
-     remove them directly in the previous cycle, since this
-     invalidates scev cache.  */
-  if (ssa_names_to_remove)
-    {
-      bitmap_iterator bi;
-
-      EXECUTE_IF_SET_IN_BITMAP (ssa_names_to_remove, 0, i, bi)
-	{
-	  gimple_stmt_iterator psi;
-	  name = ssa_name (i);
-	  phi = as_a <gphi *> (SSA_NAME_DEF_STMT (name));
-
-	  gcc_assert (gimple_code (phi) == GIMPLE_PHI);
-	  psi = gsi_for_stmt (phi);
-	  remove_phi_node (&psi, true);
-	}
-
-      BITMAP_FREE (ssa_names_to_remove);
-      scev_reset ();
-    }
-
-  /* Now the regular final value replacement.  */
-  FOR_EACH_LOOP (loop, LI_FROM_INNERMOST)
-    final_value_replacement_loop (loop);
 
-  return 0;
+  return any;
 }
 
 #include "gt-tree-scalar-evolution.h"

gcc/tree-scalar-evolution.h

@@ -33,7 +33,7 @@ extern tree analyze_scalar_evolution (struct loop *, tree);
 extern tree instantiate_scev (edge, struct loop *, tree);
 extern tree resolve_mixers (struct loop *, tree, bool *);
 extern void gather_stats_on_scev_database (void);
-extern void final_value_replacement_loop (struct loop *);
+extern bool final_value_replacement_loop (struct loop *);
 extern unsigned int scev_const_prop (void);
 extern bool expression_expensive_p (tree);
 extern bool simple_iv_with_niters (struct loop *, struct loop *, tree,

gcc/tree-ssa-loop.c

@@ -436,8 +436,7 @@ const pass_data pass_data_scev_cprop =
   0, /* properties_provided */
   0, /* properties_destroyed */
   0, /* todo_flags_start */
-  ( TODO_cleanup_cfg
-    | TODO_update_ssa_only_virtuals ), /* todo_flags_finish */
+  0, /* todo_flags_finish */
 };
 
 class pass_scev_cprop : public gimple_opt_pass
@@ -449,10 +448,24 @@ public:
 
   /* opt_pass methods: */
   virtual bool gate (function *) { return flag_tree_scev_cprop; }
-  virtual unsigned int execute (function *) { return scev_const_prop (); }
+  virtual unsigned int execute (function *);
 
 }; // class pass_scev_cprop
 
+unsigned
+pass_scev_cprop::execute (function *)
+{
+  struct loop *loop;
+  bool any = false;
+
+  /* Perform final value replacement in loops, in case the replacement
+     expressions are cheap.  */
+  FOR_EACH_LOOP (loop, LI_FROM_INNERMOST)
+    any |= final_value_replacement_loop (loop);
+
+  return any ? TODO_cleanup_cfg | TODO_update_ssa_only_virtuals : 0;
+}
+
 } // anon namespace
 
 gimple_opt_pass *