PR debug/50317

	* tree-ssa-dce.c (remove_dead_stmt): Add a debug stmt when removing
	as unnecessary a store to a variable with gimple reg type.
	* tree-ssa-live.c (remove_unused_locals): Clear TREE_ADDRESSABLE bit
	on local unreferenced variables.
	* cfgexpand.c (expand_gimple_basic_block): Don't emit DEBUG_INSNs
	for !target_for_debug_bind variables.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@181890 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 1261e4b..0ab88fa 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,13 @@
+2011-12-01  Jakub Jelinek  <jakub@redhat.com>
+
+       PR debug/50317
+       * tree-ssa-dce.c (remove_dead_stmt): Add a debug stmt when removing
+       as unnecessary a store to a variable with gimple reg type.
+       * tree-ssa-live.c (remove_unused_locals): Clear TREE_ADDRESSABLE bit
+       on local unreferenced variables.
+       * cfgexpand.c (expand_gimple_basic_block): Don't emit DEBUG_INSNs
+       for !target_for_debug_bind variables.
+
 2011-12-01  Patrick Marlier  <patrick.marlier@gmail.com>
 
        PR middle-end/51273

diff --git a/gcc/cfgexpand.c b/gcc/cfgexpand.c
index 2a82b03..e5a7a39 100644 (file)
--- a/gcc/cfgexpand.c
+++ b/gcc/cfgexpand.c
@@ -3903,6 +3903,11 @@ expand_gimple_basic_block (basic_block bb)
              rtx val;
              enum machine_mode mode;
 
+             if (TREE_CODE (var) != DEBUG_EXPR_DECL
+                 && TREE_CODE (var) != LABEL_DECL
+                 && !target_for_debug_bind (var))
+               goto delink_debug_stmt;
+
              if (gimple_debug_bind_has_value_p (stmt))
                value = gimple_debug_bind_get_value (stmt);
              else
@@ -3932,6 +3937,7 @@ expand_gimple_basic_block (basic_block bb)
                  PAT_VAR_LOCATION_LOC (val) = (rtx)value;
                }
 
+           delink_debug_stmt:
              /* In order not to generate too many debug temporaries,
                 we delink all uses of debug statements we already expanded.
                 Therefore debug statements between definition and real

diff --git a/gcc/tree-ssa-dce.c b/gcc/tree-ssa-dce.c
index d6fbe62..a710de6 100644 (file)
--- a/gcc/tree-ssa-dce.c
+++ b/gcc/tree-ssa-dce.c
@@ -1215,6 +1215,26 @@ remove_dead_stmt (gimple_stmt_iterator *i, basic_block bb)
          ei_next (&ei);
     }
 
+  /* If this is a store into a variable that is being optimized away,
+     add a debug bind stmt if possible.  */
+  if (MAY_HAVE_DEBUG_STMTS
+      && gimple_assign_single_p (stmt)
+      && is_gimple_val (gimple_assign_rhs1 (stmt)))
+    {
+      tree lhs = gimple_assign_lhs (stmt);
+      if ((TREE_CODE (lhs) == VAR_DECL || TREE_CODE (lhs) == PARM_DECL)
+         && !DECL_IGNORED_P (lhs)
+         && is_gimple_reg_type (TREE_TYPE (lhs))
+         && !is_global_var (lhs)
+         && !DECL_HAS_VALUE_EXPR_P (lhs))
+       {
+         tree rhs = gimple_assign_rhs1 (stmt);
+         gimple note
+           = gimple_build_debug_bind (lhs, unshare_expr (rhs), stmt);
+         gsi_insert_after (i, note, GSI_SAME_STMT);
+       }
+    }
+
   unlink_stmt_vdef (stmt);
   gsi_remove (i, true);
   release_defs (stmt);

diff --git a/gcc/tree-ssa-live.c b/gcc/tree-ssa-live.c
index b8a056e..103e4f7 100644 (file)
--- a/gcc/tree-ssa-live.c
+++ b/gcc/tree-ssa-live.c
@@ -1,5 +1,5 @@
 /* Liveness for SSA trees.
-   Copyright (C) 2003, 2004, 2005, 2007, 2008, 2009, 2010
+   Copyright (C) 2003, 2004, 2005, 2007, 2008, 2009, 2010, 2011
    Free Software Foundation, Inc.
    Contributed by Andrew MacLeod <amacleod@redhat.com>
 
@@ -814,7 +814,15 @@ remove_unused_locals (void)
              bitmap_set_bit (global_unused_vars, DECL_UID (var));
            }
          else
-           continue;
+           {
+             /* For unreferenced local vars drop TREE_ADDRESSABLE
+                bit in case it is referenced from debug stmts.  */
+             if (DECL_CONTEXT (var) == current_function_decl
+                 && TREE_ADDRESSABLE (var)
+                 && is_gimple_reg_type (TREE_TYPE (var)))
+               TREE_ADDRESSABLE (var) = 0;
+             continue;
+           }
        }
       else if (TREE_CODE (var) == VAR_DECL
               && DECL_HARD_REGISTER (var)