[PATCH] Add SCEV cprop dump

[Marek Polacek]

This is an attempt to add more dumping to scev_cprop.  I don't know what exactly
would you want to see in there, so now it prints e.g.:

(replace_stmt 
  (virtual_p_1 with 0)
)

and

(final_value_replacement 
  o__lsm.3_2 = PHI <_6(4)>
  with 
  o__lsm.3_2 = pretmp_10 + 20; 
)

Comments?  Maybe that first hunk isn't really neccessary.

2013-05-15  Marek Polacek  <polacek@redhat.com>

	* tree-scalar-evolution.c (scev_const_prop): Add more dumps.

--- gcc/tree-scalar-evolution.c.mp	2013-05-15 13:43:31.020698846 +0200
+++ gcc/tree-scalar-evolution.c	2013-05-15 13:43:58.080788354 +0200
@@ -3295,7 +3295,17 @@ scev_const_prop (void)
 
 	  /* Replace the uses of the name.  */
 	  if (name != ev)
-	    replace_uses_by (name, ev);
+	    {
+	      replace_uses_by (name, ev);
+	      if (dump_file && (dump_flags & TDF_SCEV))
+		{
+		  fprintf (dump_file, "(replace_stmt \n  (");
+		  print_generic_expr (dump_file, name, 0);
+		  fprintf (dump_file, " with ");
+		  print_generic_expr (dump_file, ev, 0);
+		  fprintf (dump_file, ")\n) \n");
+		}
+	     }
 
 	  if (!ssa_names_to_remove)
 	    ssa_names_to_remove = BITMAP_ALLOC (NULL);
@@ -3391,6 +3401,12 @@ scev_const_prop (void)
 
 	  /* Eliminate the PHI node and replace it by a computation outside
 	     the loop.  */
+	  if (dump_file && (dump_flags & TDF_SCEV))
+	    {
+	      fprintf (dump_file, "(final_value_replacement \n  ");
+	      print_gimple_stmt (dump_file, phi, 0, 0);
+	      fprintf (dump_file, "  with \n  ");
+	    }
 	  def = unshare_expr (def);
 	  remove_phi_node (&psi, false);
 
@@ -3398,6 +3414,11 @@ scev_const_prop (void)
       					  true, GSI_SAME_STMT);
 	  ass = gimple_build_assign (rslt, def);
 	  gsi_insert_before (&bsi, ass, GSI_SAME_STMT);
+	  if (dump_file && (dump_flags & TDF_SCEV))
+	    {
+	      print_gimple_stmt (dump_file, ass, 0, 0);
+	      fprintf (dump_file, ") \n");
+	    }
 	}
     }
   return 0;

	Marek