2006-01-05 Richard Guenther <rguenther@suse.de>

	    Diego Novillo  <dnovillo@redhat.com>

	* tree-pass.h (TODO_remove_unused_locals): Define.
	* gimple-low.c (expand_var_p, remove_useless_vars,
	pass_remove_useless_vars): Remove.  Update all users.
	* tree-ssa-live.c (mark_all_vars_used_1): Handle SSA names.
	(remove_unused_locals): New function.
	* tree-flow.h (remove_unused_locals): Declare.
	* passes.c (execute_todo): Call remove_unused_locals if
	TODO_remove_unused_locals is set.
	* tree-into-ssa.c (pass_build_ssa): Add TODO_remove_unused_locals.
	* tree-ssa-dce.c (pass_dce): Likewise.
	* tree-outof-ssa.c (pass_del_ssa): Likewise.

	* gcc.dg/tree-ssa/loop-11.c: Deal with removed vars pass.
	* gcc.dg/tree-ssa/loop-8.c: Likewise.
	* gcc.dg/tree-ssa/loop-1.c: Likewise.
	* gcc.dg/tree-ssa/pr23294.c: Likewise.
	* gcc.dg/tree-ssa/pr21985.c: Likewise.
	* gcc.dg/tree-ssa/loop-14.c: Likewise.
	* gcc.dg/tree-ssa/loop-2.c: Likewise.
	* gcc.dg/tree-ssa/loop-3.c: Likewise.
	* gcc.dg/tree-ssa/loop-4.c: Likewise.
	* gcc.dg/tree-ssa/pr21171.c: Likewise.
	* gcc.dg/tree-ssa/loop-5.c: Likewise.
	* gcc.dg/tree-ssa/loop-10.c: Likewise.
	* gcc.dg/tree-ssa/loop-6.c: Likewise.
	* treelang/compile/extravar.tree: Likewise.
	* g++.dg/tree-ssa/ssa-cast-1.C: Likewise.
	* g++.dg/tree-ssa/pointer-reference-alias.C: Likewise.
	* g++.dg/tree-ssa/ssa-sra-1.C: Likewise.
	* g++.dg/tree-ssa/ssa-sra-2.C: Likewise.
	* gcc.dg/tree-ssa/20031106-6.c: Disable SRA.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@109379 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 70 insertions, 0 deletions

diff --git a/gcc/tree-ssa-live.c b/gcc/tree-ssa-live.c
index 8c02a2b4b66..e011a5d250c 100644
--- a/gcc/tree-ssa-live.c
+++ b/gcc/tree-ssa-live.c
@@ -296,6 +296,9 @@ mark_all_vars_used_1 (tree *tp, int *walk_subtrees,
 {
   tree t = *tp;
 
+  if (TREE_CODE (t) == SSA_NAME)
+    t = SSA_NAME_VAR (t);
+
   /* Ignore TREE_ORIGINAL for TARGET_MEM_REFS, as well as other
      fields that do not contain vars.  */
   if (TREE_CODE (t) == TARGET_MEM_REF)
@@ -327,6 +330,72 @@ mark_all_vars_used (tree *expr_p)
   walk_tree (expr_p, mark_all_vars_used_1, NULL, NULL);
 }
 
+
+/* Remove local variables that are not referenced in the IL.  */
+
+void
+remove_unused_locals (void)
+{
+  basic_block bb;
+  tree t, *cell;
+
+  /* Assume all locals are unused.  */
+  for (t = cfun->unexpanded_var_list; t; t = TREE_CHAIN (t))
+    {
+      tree var = TREE_VALUE (t);
+      if (TREE_CODE (var) != FUNCTION_DECL
+	  && var_ann (var))
+	var_ann (var)->used = false;
+    }
+
+  /* Walk the CFG marking all referenced symbols.  */
+  FOR_EACH_BB (bb)
+    {
+      block_stmt_iterator bsi;
+      tree phi, def;
+
+      /* Walk the statements.  */
+      for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
+	mark_all_vars_used (bsi_stmt_ptr (bsi));
+
+      for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
+        {
+          use_operand_p arg_p;
+          ssa_op_iter i;
+
+	  /* No point processing globals.  */
+	  if (is_global_var (SSA_NAME_VAR (PHI_RESULT (phi))))
+	    continue;
+
+          def = PHI_RESULT (phi);
+          mark_all_vars_used (&def);
+
+          FOR_EACH_PHI_ARG (arg_p, phi, i, SSA_OP_ALL_USES)
+            {
+	      tree arg = USE_FROM_PTR (arg_p);
+	      mark_all_vars_used (&arg);
+            }
+        }
+    }
+
+  /* Remove unmarked vars and clear used flag.  */
+  for (cell = &cfun->unexpanded_var_list; *cell; )
+    {
+      tree var = TREE_VALUE (*cell);
+      var_ann_t ann;
+
+      if (TREE_CODE (var) != FUNCTION_DECL
+	  && (!(ann = var_ann (var))
+	      || !ann->used))
+	{
+	  *cell = TREE_CHAIN (*cell);
+	  continue;
+	}
+
+      cell = &TREE_CHAIN (*cell);
+    }
+}
+
 /* This function looks through the program and uses FLAGS to determine what 
    SSA versioned variables are given entries in a new partition table.  This
    new partition map is returned.  */
@@ -362,6 +431,7 @@ create_ssa_var_map (int flags)
   FOR_EACH_BB (bb)
     {
       tree phi, arg;
+
       for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
 	{
 	  int i;