From patchwork Tue Jun 22 09:52:32 2010
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Subject: Fix bug with noreturn call
Date: Mon, 21 Jun 2010 23:52:32 -0000
From: Eric Botcazou <ebotcazou@adacore.com>
X-Patchwork-Id: 56447
Message-Id: <201006221152.32983.ebotcazou@adacore.com>
To: Richard Guenther <richard.guenther@gmail.com>
Cc: Jan Hubicka <hubicka@ucw.cz>, gcc-patches@gcc.gnu.org

> A patch to do so is pre-approved if it passes bootstrap & regtest.

Here is the patch that I've been playing with this morning.


        * cgraphunit.c (cgraph_redirect_edge_call_stmt_to_callee): Chain the
        new statement and adjust VDEF only if necessary.  Remove superfluous
        call to maybe_clean_or_replace_eh_stmt.
        * gimple.c (gimple_call_copy_skip_args): Use gimple_call_copy_flags to
        copy the flags.
	* gimple-iterator.c (gsi_replace): Clear BB of old statement here.
	* tree-inline.c (copy_bb): Do not clear BB of old statement here.


Index: cgraphunit.c
===================================================================
--- cgraphunit.c	(revision 161023)
+++ cgraphunit.c	(working copy)
@@ -2345,7 +2345,6 @@ cgraph_redirect_edge_call_stmt_to_callee
 {
   tree decl = gimple_call_fndecl (e->call_stmt);
   gimple new_stmt;
-  gimple_stmt_iterator gsi;
 #ifdef ENABLE_CHECKING
   struct cgraph_node *node;
 #endif
@@ -2367,29 +2366,34 @@ cgraph_redirect_edge_call_stmt_to_callee
 	       cgraph_node_name (e->callee), e->callee->uid);
       print_gimple_stmt (cgraph_dump_file, e->call_stmt, 0, dump_flags);
       if (e->callee->clone.combined_args_to_skip)
-        {
-          fprintf (cgraph_dump_file, " combined args to skip: ");
-          dump_bitmap (cgraph_dump_file, e->callee->clone.combined_args_to_skip);
+	{
+	  fprintf (cgraph_dump_file, " combined args to skip: ");
+	  dump_bitmap (cgraph_dump_file,
+		       e->callee->clone.combined_args_to_skip);
 	}
     }
 
   if (e->callee->clone.combined_args_to_skip)
-    new_stmt = gimple_call_copy_skip_args (e->call_stmt,
-				       e->callee->clone.combined_args_to_skip);
+    {
+      gimple_stmt_iterator gsi;
+
+      new_stmt
+	= gimple_call_copy_skip_args (e->call_stmt,
+				      e->callee->clone.combined_args_to_skip);
+
+      if (gimple_vdef (new_stmt)
+	  && TREE_CODE (gimple_vdef (new_stmt)) == SSA_NAME)
+	SSA_NAME_DEF_STMT (gimple_vdef (new_stmt)) = new_stmt;
+
+      gsi = gsi_for_stmt (e->call_stmt);
+      gsi_replace (&gsi, new_stmt, true);
+    }
   else
     new_stmt = e->call_stmt;
-  if (gimple_vdef (new_stmt)
-      && TREE_CODE (gimple_vdef (new_stmt)) == SSA_NAME)
-    SSA_NAME_DEF_STMT (gimple_vdef (new_stmt)) = new_stmt;
-  gimple_call_set_fndecl (new_stmt, e->callee->decl);
 
-  gsi = gsi_for_stmt (e->call_stmt);
-  gsi_replace (&gsi, new_stmt, true);
+  gimple_call_set_fndecl (new_stmt, e->callee->decl);
   update_stmt (new_stmt);
 
-  /* Update EH information too, just in case.  */
-  maybe_clean_or_replace_eh_stmt (e->call_stmt, new_stmt);
-
   cgraph_set_call_stmt_including_clones (e->caller, e->call_stmt, new_stmt);
 
   if (cgraph_dump_file)
Index: gimple.c
===================================================================
--- gimple.c	(revision 161023)
+++ gimple.c	(working copy)
@@ -3085,14 +3085,8 @@ gimple_call_copy_skip_args (gimple stmt,
   gimple_set_block (new_stmt, gimple_block (stmt));
   if (gimple_has_location (stmt))
     gimple_set_location (new_stmt, gimple_location (stmt));
-
-  /* Carry all the flags to the new GIMPLE_CALL.  */
+  gimple_call_copy_flags (new_stmt, stmt);
   gimple_call_set_chain (new_stmt, gimple_call_chain (stmt));
-  gimple_call_set_tail (new_stmt, gimple_call_tail_p (stmt));
-  gimple_call_set_cannot_inline (new_stmt, gimple_call_cannot_inline_p (stmt));
-  gimple_call_set_return_slot_opt (new_stmt, gimple_call_return_slot_opt_p (stmt));
-  gimple_call_set_from_thunk (new_stmt, gimple_call_from_thunk_p (stmt));
-  gimple_call_set_va_arg_pack (new_stmt, gimple_call_va_arg_pack_p (stmt));
 
   gimple_set_modified (new_stmt, true);
 
Index: gimple-iterator.c
===================================================================
--- gimple-iterator.c	(revision 161023)
+++ gimple-iterator.c	(working copy)
@@ -381,8 +381,12 @@ gsi_replace (gimple_stmt_iterator *gsi,
     maybe_clean_or_replace_eh_stmt (orig_stmt, stmt);
 
   gimple_duplicate_stmt_histograms (cfun, stmt, cfun, orig_stmt);
+
+  /* Free all the data flow information for OLD_STMT.  */
+  gimple_set_bb (orig_stmt, NULL);
   gimple_remove_stmt_histograms (cfun, orig_stmt);
   delink_stmt_imm_use (orig_stmt);
+
   *gsi_stmt_ptr (gsi) = stmt;
   gimple_set_modified (stmt, true);
   update_modified_stmt (stmt);
Index: tree-inline.c
===================================================================
--- tree-inline.c	(revision 161023)
+++ tree-inline.c	(working copy)
@@ -1604,7 +1604,6 @@ copy_bb (copy_body_data *id, basic_block
 	      gimple_call_set_lhs (new_call, gimple_call_lhs (stmt));
 
 	      gsi_replace (&copy_gsi, new_call, false);
-	      gimple_set_bb (stmt, NULL);
 	      stmt = new_call;
 	    }
 	  else if (is_gimple_call (stmt)