tree-into-ssa.c (rewrite_stmt): Remove clobbers for variables we rewrite into SSA...

2012-08-07  Richard Guenther  <rguenther@suse.de>

	* tree-into-ssa.c (rewrite_stmt): Remove clobbers for variables
	we rewrite into SSA form.
	(rewrite_enter_block): Adjust.
	* gimple-iterator.c (gsi_replace): Also allow replacement with
	a stmt without a lhs.
	* tree-ssa-live.c (remove_unused_locals): Remove code handling
	clobbers of SSA names.
	* tree-nested.c (convert_local_reference_stmt): Remove clobbers
	for variables we access through the local chain.
	* tree-cfg.c (verify_gimple_assign_single): Verify clobbers
	clobber full decls only.

From-SVN: r190200

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index b732bed..65f194a 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,19 @@
 2012-08-07  Richard Guenther  <rguenther@suse.de>
 
+       * tree-into-ssa.c (rewrite_stmt): Remove clobbers for variables
+       we rewrite into SSA form.
+       (rewrite_enter_block): Adjust.
+       * gimple-iterator.c (gsi_replace): Also allow replacement with
+       a stmt without a lhs.
+       * tree-ssa-live.c (remove_unused_locals): Remove code handling
+       clobbers of SSA names.
+       * tree-nested.c (convert_local_reference_stmt): Remove clobbers
+       for variables we access through the local chain.
+       * tree-cfg.c (verify_gimple_assign_single): Verify clobbers
+       clobber full decls only.
+
+2012-08-07  Richard Guenther  <rguenther@suse.de>
+
        * gimple.h (gimple_phi_set_result): Adjust SSA_NAME_DEF_STMT.
        * tree-phinodes.c (make_phi_node): Allow a NULL var.
        * tree-into-ssa.c (insert_phi_nodes_for): Simplify.

diff --git a/gcc/gimple-iterator.c b/gcc/gimple-iterator.c
index 0f1d497..914685c 100644 (file)
--- a/gcc/gimple-iterator.c
+++ b/gcc/gimple-iterator.c
@@ -427,7 +427,7 @@ gsi_replace (gimple_stmt_iterator *gsi, gimple stmt, bool update_eh_info)
   if (stmt == orig_stmt)
     return;
 
-  gcc_assert (!gimple_has_lhs (orig_stmt)
+  gcc_assert (!gimple_has_lhs (orig_stmt) || !gimple_has_lhs (stmt)
              || gimple_get_lhs (orig_stmt) == gimple_get_lhs (stmt));
 
   gimple_set_location (stmt, gimple_location (orig_stmt));

diff --git a/gcc/tree-cfg.c b/gcc/tree-cfg.c
index 601899c..bc4045e 100644 (file)
--- a/gcc/tree-cfg.c
+++ b/gcc/tree-cfg.c
@@ -3930,6 +3930,14 @@ verify_gimple_assign_single (gimple stmt)
       return true;
     }
 
+  if (gimple_clobber_p (stmt)
+      && !DECL_P (lhs))
+    {
+      error ("non-decl LHS in clobber statement");
+      debug_generic_expr (lhs);
+      return true;
+    }
+
   if (handled_component_p (lhs))
     res |= verify_types_in_gimple_reference (lhs, true);
 

diff --git a/gcc/tree-into-ssa.c b/gcc/tree-into-ssa.c
index 1350d77..74ef7f5 100644 (file)
--- a/gcc/tree-into-ssa.c
+++ b/gcc/tree-into-ssa.c
@@ -1323,12 +1323,12 @@ rewrite_debug_stmt_uses (gimple stmt)
    definition of a variable when a new real or virtual definition is found.  */
 
 static void
-rewrite_stmt (gimple_stmt_iterator si)
+rewrite_stmt (gimple_stmt_iterator *si)
 {
   use_operand_p use_p;
   def_operand_p def_p;
   ssa_op_iter iter;
-  gimple stmt = gsi_stmt (si);
+  gimple stmt = gsi_stmt (*si);
 
   /* If mark_def_sites decided that we don't need to rewrite this
      statement, ignore it.  */
@@ -1362,9 +1362,24 @@ rewrite_stmt (gimple_stmt_iterator si)
     FOR_EACH_SSA_DEF_OPERAND (def_p, stmt, iter, SSA_OP_ALL_DEFS)
       {
        tree var = DEF_FROM_PTR (def_p);
-       tree name = make_ssa_name (var, stmt);
+       tree name;
        tree tracked_var;
+
        gcc_assert (DECL_P (var));
+
+       if (gimple_clobber_p (stmt)
+           && is_gimple_reg (var))
+         {
+           /* If we rewrite a DECL into SSA form then drop its
+              clobber stmts and replace uses with a new default def.  */
+           gcc_assert (TREE_CODE (var) == VAR_DECL
+                       && !gimple_vdef (stmt));
+           gsi_replace (si, gimple_build_nop (), true);
+           register_new_def (get_or_create_ssa_default_def (cfun, var), var);
+           break;
+         }
+
+       name = make_ssa_name (var, stmt);
        SET_DEF (def_p, name);
        register_new_def (DEF_FROM_PTR (def_p), var);
 
@@ -1372,7 +1387,7 @@ rewrite_stmt (gimple_stmt_iterator si)
        if (tracked_var)
          {
            gimple note = gimple_build_debug_bind (tracked_var, name, stmt);
-           gsi_insert_after (&si, note, GSI_SAME_STMT);
+           gsi_insert_after (si, note, GSI_SAME_STMT);
          }
       }
 }
@@ -1439,7 +1454,7 @@ rewrite_enter_block (struct dom_walk_data *walk_data ATTRIBUTE_UNUSED,
      of a variable when a new real or virtual definition is found.  */
   if (TEST_BIT (interesting_blocks, bb->index))
     for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
-      rewrite_stmt (gsi);
+      rewrite_stmt (&gsi);
 
   /* Step 3.  Visit all the successor blocks of BB looking for PHI nodes.
      For every PHI node found, add a new argument containing the current

diff --git a/gcc/tree-nested.c b/gcc/tree-nested.c
index c0a6250..0b99803 100644 (file)
--- a/gcc/tree-nested.c
+++ b/gcc/tree-nested.c
@@ -1727,6 +1727,20 @@ convert_local_reference_stmt (gimple_stmt_iterator *gsi, bool *handled_ops_p,
       *handled_ops_p = false;
       return NULL_TREE;
 
+    case GIMPLE_ASSIGN:
+      if (gimple_clobber_p (stmt))
+       {
+         tree lhs = gimple_assign_lhs (stmt);
+         if (!use_pointer_in_frame (lhs)
+             && lookup_field_for_decl (info, lhs, NO_INSERT))
+           {
+             gsi_replace (gsi, gimple_build_nop (), true);
+             break;
+           }
+       }
+      *handled_ops_p = false;
+      return NULL_TREE;
+
     default:
       /* For every other statement that we are not interested in
         handling here, let the walker traverse the operands.  */

diff --git a/gcc/tree-ssa-live.c b/gcc/tree-ssa-live.c
index 8692696..903faa9 100644 (file)
--- a/gcc/tree-ssa-live.c
+++ b/gcc/tree-ssa-live.c
@@ -773,9 +773,6 @@ remove_unused_locals (void)
            if (gimple_clobber_p (stmt))
              {
                tree lhs = gimple_assign_lhs (stmt);
-               lhs = get_base_address (lhs);
-               if (TREE_CODE (lhs) == SSA_NAME)
-                 lhs = SSA_NAME_VAR (lhs);
                if (TREE_CODE (lhs) == VAR_DECL && !is_used_p (lhs))
                  {
                    unlink_stmt_vdef (stmt);