[gcc] GCC 4.5.0=>4.5.1

gcc/gcc/tree-tailcall.c

Index: gcc/gcc/tree-tailcall.c
diff --git a/gcc/gcc/tree-tailcall.c b/gcc/gcc/tree-tailcall.c
index 9d2513d271dc70931732e4c34688ebd58961d830..a9bbc9796019f53992b87e7f508b1f65faf52bad 100644
--- a/gcc/gcc/tree-tailcall.c
+++ b/gcc/gcc/tree-tailcall.c
@@ -1,5 +1,5 @@
 /* Tail call optimization on trees.
-   Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008
+   Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
    Free Software Foundation, Inc.
 
 This file is part of GCC.
@@ -65,7 +65,7 @@ along with GCC; see the file COPYING3.  If not see
      return acc;
    }
 
-   To do this, we maintain two accumulators (a_acc and m_acc) that indicate 
+   To do this, we maintain two accumulators (a_acc and m_acc) that indicate
    when we reach the return x statement, we should return a_acc + x * m_acc
    instead.  They are initially initialized to 0 and 1, respectively,
    so the semantics of the function is obviously preserved.  If we are
@@ -79,12 +79,12 @@ along with GCC; see the file COPYING3.  If not see
 
    1) Just return x, where x is not in any of the remaining special shapes.
       We rewrite this to a gimple equivalent of return m_acc * x + a_acc.
-      
+
    2) return f (...), where f is the current function, is rewritten in a
       classical tail-recursion elimination way, into assignment of arguments
       and jump to the start of the function.  Values of the accumulators
       are unchanged.
-	       
+
    3) return a + m * f(...), where a and m do not depend on call to f.
       To preserve the semantics described before we want this to be rewritten
       in such a way that we finally return
@@ -136,15 +136,11 @@ suitable_for_tail_opt_p (void)
   if (cfun->stdarg)
     return false;
 
-  /* No local variable nor structure field should be call-used.  We
-     ignore any kind of memory tag, as these are not real variables.  */
-
+  /* No local variable nor structure field should be call-used.  */
   FOR_EACH_REFERENCED_VAR (var, rvi)
     {
       if (!is_global_var (var)
-	  && !MTAG_P (var)
-	  && (gimple_aliases_computed_p (cfun)? is_call_used (var)
-	      : TREE_ADDRESSABLE (var)))
+	  && is_call_used (var))
 	return false;
     }
 
@@ -215,7 +211,7 @@ independent_of_stmt_p (tree expr, gimple at, gimple_stmt_iterator gsi)
   bb->aux = &bb->aux;
 
   while (1)
-    { 
+    {
       at = SSA_NAME_DEF_STMT (expr);
       bb = gimple_bb (at);
 
@@ -274,7 +270,7 @@ process_assignment (gimple stmt, gimple_stmt_iterator call, tree *m,
   enum tree_code code = gimple_assign_rhs_code (stmt);
   enum gimple_rhs_class rhs_class = get_gimple_rhs_class (code);
   tree src_var = gimple_assign_rhs1 (stmt);
-  
+
   /* See if this is a simple copy operation of an SSA name to the function
      result.  In that case we may have a simple tail call.  Ignore type
      conversions that can never produce extra code between the function
@@ -330,22 +326,11 @@ process_assignment (gimple stmt, gimple_stmt_iterator call, tree *m,
   switch (code)
     {
     case PLUS_EXPR:
-      /* There should be no previous addition.  TODO -- it should be fairly
-	 straightforward to lift this restriction -- just allow storing
-	 more complicated expressions in *A, and gimplify it in
-	 adjust_accumulator_values.  */
-      if (*a)
-	return false;
       *a = non_ass_var;
       *ass_var = dest;
       return true;
 
     case MULT_EXPR:
-      /* Similar remark applies here.  Handling multiplication after addition
-	 is just slightly more complicated -- we need to multiply both *A and
-	 *M.  */
-      if (*a || *m)
-	return false;
       *m = non_ass_var;
       *ass_var = dest;
       return true;
@@ -365,7 +350,7 @@ propagate_through_phis (tree var, edge e)
 {
   basic_block dest = e->dest;
   gimple_stmt_iterator gsi;
- 
+
   for (gsi = gsi_start_phis (dest); !gsi_end_p (gsi); gsi_next (&gsi))
     {
       gimple phi = gsi_stmt (gsi);
@@ -390,6 +375,8 @@ find_tail_calls (basic_block bb, struct tailcall **ret)
   tree m, a;
   basic_block abb;
   size_t idx;
+  tree var;
+  referenced_var_iterator rvi;
 
   if (!single_succ_p (bb))
     return;
@@ -399,7 +386,7 @@ find_tail_calls (basic_block bb, struct tailcall **ret)
       stmt = gsi_stmt (gsi);
 
       /* Ignore labels.  */
-      if (gimple_code (stmt) == GIMPLE_LABEL)
+      if (gimple_code (stmt) == GIMPLE_LABEL || is_gimple_debug (stmt))
 	continue;
 
       /* Check for a call.  */
@@ -410,11 +397,9 @@ find_tail_calls (basic_block bb, struct tailcall **ret)
 	  break;
 	}
 
-      /* If the statement has virtual or volatile operands, fail.  */
-      if (!ZERO_SSA_OPERANDS (stmt, (SSA_OP_VUSE | SSA_OP_VIRTUAL_DEFS))
-	  || gimple_has_volatile_ops (stmt)
-	  || (!gimple_aliases_computed_p (cfun)
-	      && gimple_references_memory_p (stmt)))
+      /* If the statement references memory or volatile operands, fail.  */
+      if (gimple_references_memory_p (stmt)
+	  || gimple_has_volatile_ops (stmt))
 	return;
     }
 
@@ -428,7 +413,7 @@ find_tail_calls (basic_block bb, struct tailcall **ret)
       return;
     }
 
-  /* If the LHS of our call is not just a simple register, we can't 
+  /* If the LHS of our call is not just a simple register, we can't
      transform this into a tail or sibling call.  This situation happens,
      in (e.g.) "*p = foo()" where foo returns a struct.  In this case
      we won't have a temporary here, but we need to carry out the side
@@ -479,6 +464,16 @@ find_tail_calls (basic_block bb, struct tailcall **ret)
 	tail_recursion = true;
     }
 
+  /* Make sure the tail invocation of this function does not refer
+     to local variables.  */
+  FOR_EACH_REFERENCED_VAR (var, rvi)
+    {
+      if (TREE_CODE (var) != PARM_DECL
+	  && auto_var_in_fn_p (var, cfun->decl)
+	  && ref_maybe_used_by_stmt_p (call, var))
+	return;
+    }
+
   /* Now check the statements after the call.  None of them has virtual
      operands, so they may only depend on the call through its return
      value.  The return value should also be dependent on each of them,
@@ -490,6 +485,8 @@ find_tail_calls (basic_block bb, struct tailcall **ret)
   agsi = gsi;
   while (1)
     {
+      tree tmp_a = NULL_TREE;
+      tree tmp_m = NULL_TREE;
       gsi_next (&agsi);
 
       while (gsi_end_p (agsi))
@@ -507,12 +504,33 @@ find_tail_calls (basic_block bb, struct tailcall **ret)
       if (gimple_code (stmt) == GIMPLE_RETURN)
 	break;
 
+      if (is_gimple_debug (stmt))
+	continue;
+
       if (gimple_code (stmt) != GIMPLE_ASSIGN)
 	return;
 
       /* This is a gimple assign. */
-      if (! process_assignment (stmt, gsi, &m, &a, &ass_var))
+      if (! process_assignment (stmt, gsi, &tmp_m, &tmp_a, &ass_var))
 	return;
+
+      if (tmp_a)
+	{
+	  if (a)
+	    a = fold_build2 (PLUS_EXPR, TREE_TYPE (tmp_a), a, tmp_a);
+	  else
+	    a = tmp_a;
+	}
+      if (tmp_m)
+	{
+	  if (m)
+	    m = fold_build2 (MULT_EXPR, TREE_TYPE (tmp_m), m, tmp_m);
+	  else
+	    m = tmp_m;
+
+	  if (a)
+	    a = fold_build2 (MULT_EXPR, TREE_TYPE (tmp_m), a, tmp_m);
+	}
     }
 
   /* See if this is a tail call we can handle.  */
@@ -554,7 +572,7 @@ add_successor_phi_arg (edge e, tree var, tree phi_arg)
       break;
 
   gcc_assert (!gsi_end_p (gsi));
-  add_phi_arg (gsi_stmt (gsi), phi_arg, e);
+  add_phi_arg (gsi_stmt (gsi), phi_arg, e, UNKNOWN_LOCATION);
 }
 
 /* Creates a GIMPLE statement which computes the operation specified by
@@ -563,28 +581,42 @@ add_successor_phi_arg (edge e, tree var, tree phi_arg)
    tree node of the statement's result.  */
 
 static tree
-adjust_return_value_with_ops (enum tree_code code, const char *label, 
-			      tree op0, tree op1, gimple_stmt_iterator gsi,
-			      enum gsi_iterator_update update)
+adjust_return_value_with_ops (enum tree_code code, const char *label,
+			      tree acc, tree op1, gimple_stmt_iterator gsi)
 {
 
   tree ret_type = TREE_TYPE (DECL_RESULT (current_function_decl));
   tree tmp = create_tmp_var (ret_type, label);
-  gimple stmt = gimple_build_assign_with_ops (code, tmp, op0, op1);
+  gimple stmt;
   tree result;
 
   if (TREE_CODE (ret_type) == COMPLEX_TYPE
       || TREE_CODE (ret_type) == VECTOR_TYPE)
     DECL_GIMPLE_REG_P (tmp) = 1;
   add_referenced_var (tmp);
+
+  if (types_compatible_p (TREE_TYPE (acc), TREE_TYPE (op1)))
+    stmt = gimple_build_assign_with_ops (code, tmp, acc, op1);
+  else
+    {
+      tree rhs = fold_convert (TREE_TYPE (acc),
+			       fold_build2 (code,
+					    TREE_TYPE (op1),
+					    fold_convert (TREE_TYPE (op1), acc),
+					    op1));
+      rhs = force_gimple_operand_gsi (&gsi, rhs,
+				      false, NULL, true, GSI_CONTINUE_LINKING);
+      stmt = gimple_build_assign (NULL_TREE, rhs);
+    }
+
   result = make_ssa_name (tmp, stmt);
   gimple_assign_set_lhs (stmt, result);
   update_stmt (stmt);
-  gsi_insert_before (&gsi, stmt, update);
+  gsi_insert_before (&gsi, stmt, GSI_NEW_STMT);
   return result;
 }
 
-/* Creates a new GIMPLE statement that adjusts the value of accumulator ACC by 
+/* Creates a new GIMPLE statement that adjusts the value of accumulator ACC by
    the computation specified by CODE and OP1 and insert the statement
    at the position specified by GSI as a new statement.  Returns new SSA name
    of updated accumulator.  */
@@ -593,9 +625,22 @@ static tree
 update_accumulator_with_ops (enum tree_code code, tree acc, tree op1,
 			     gimple_stmt_iterator gsi)
 {
-  gimple stmt = gimple_build_assign_with_ops (code, SSA_NAME_VAR (acc), acc,
-					      op1);
-  tree var = make_ssa_name (SSA_NAME_VAR (acc), stmt);
+  gimple stmt;
+  tree var;
+  if (types_compatible_p (TREE_TYPE (acc), TREE_TYPE (op1)))
+    stmt = gimple_build_assign_with_ops (code, SSA_NAME_VAR (acc), acc, op1);
+  else
+    {
+      tree rhs = fold_convert (TREE_TYPE (acc),
+			       fold_build2 (code,
+					    TREE_TYPE (op1),
+					    fold_convert (TREE_TYPE (op1), acc),
+					    op1));
+      rhs = force_gimple_operand_gsi (&gsi, rhs,
+				      false, NULL, false, GSI_CONTINUE_LINKING);
+      stmt = gimple_build_assign (NULL_TREE, rhs);
+    }
+  var = make_ssa_name (SSA_NAME_VAR (acc), stmt);
   gimple_assign_set_lhs (stmt, var);
   update_stmt (stmt);
   gsi_insert_after (&gsi, stmt, GSI_NEW_STMT);
@@ -608,8 +653,15 @@ update_accumulator_with_ops (enum tree_code code, tree acc, tree op1,
 static void
 adjust_accumulator_values (gimple_stmt_iterator gsi, tree m, tree a, edge back)
 {
-  tree var, a_acc_arg = a_acc, m_acc_arg = m_acc;
+  tree var, a_acc_arg, m_acc_arg;
+
+  if (m)
+    m = force_gimple_operand_gsi (&gsi, m, true, NULL, true, GSI_SAME_STMT);
+  if (a)
+    a = force_gimple_operand_gsi (&gsi, a, true, NULL, true, GSI_SAME_STMT);
 
+  a_acc_arg = a_acc;
+  m_acc_arg = m_acc;
   if (a)
     {
       if (m_acc)
@@ -618,7 +670,7 @@ adjust_accumulator_values (gimple_stmt_iterator gsi, tree m, tree a, edge back)
 	    var = m_acc;
 	  else
 	    var = adjust_return_value_with_ops (MULT_EXPR, "acc_tmp", m_acc,
-						a, gsi, GSI_NEW_STMT);
+						a, gsi);
 	}
       else
 	var = a;
@@ -654,10 +706,10 @@ adjust_return_value (basic_block bb, tree m, tree a)
 
   if (m)
     retval = adjust_return_value_with_ops (MULT_EXPR, "mul_tmp", m_acc, retval,
-					   gsi, GSI_SAME_STMT);
+					   gsi);
   if (a)
     retval = adjust_return_value_with_ops (PLUS_EXPR, "acc_tmp", a_acc, retval,
-					   gsi, GSI_SAME_STMT);
+					   gsi);
   gimple_return_set_retval (ret_stmt, retval);
   update_stmt (ret_stmt);
 }
@@ -695,7 +747,7 @@ arg_needs_copy_p (tree param)
 
   if (!is_gimple_reg (param) || !var_ann (param))
     return false;
-		
+
   /* Parameters that are only defined but never used need not be copied.  */
   def = gimple_default_def (cfun, param);
   if (!def)
@@ -779,7 +831,7 @@ eliminate_tail_call (struct tailcall *t)
       phi = gsi_stmt (gsi);
       gcc_assert (param == SSA_NAME_VAR (PHI_RESULT (phi)));
 
-      add_phi_arg (phi, arg, e);
+      add_phi_arg (phi, arg, e, gimple_location (stmt));
       gsi_next (&gsi);
     }
 
@@ -876,10 +928,11 @@ create_tailcall_accumulator (const char *label, basic_block bb, tree init)
   add_referenced_var (tmp);
   phi = create_phi_node (tmp, bb);
   /* RET_TYPE can be a float when -ffast-maths is enabled.  */
-  add_phi_arg (phi, fold_convert (ret_type, init), single_pred_edge (bb));
+  add_phi_arg (phi, fold_convert (ret_type, init), single_pred_edge (bb),
+	       UNKNOWN_LOCATION);
   return PHI_RESULT (phi);
 }
- 
+
 /* Optimizes tail calls in the function, turning the tail recursion
    into iteration.  */
 
@@ -939,7 +992,8 @@ tree_optimize_tail_calls_1 (bool opt_tailcalls)
 		set_default_def (param, new_name);
 		phi = create_phi_node (name, first);
 		SSA_NAME_DEF_STMT (name) = phi;
-		add_phi_arg (phi, new_name, single_pred_edge (first));
+		add_phi_arg (phi, new_name, single_pred_edge (first),
+			     EXPR_LOCATION (param));
 	      }
 	  phis_constructed = true;
 	}
@@ -1001,7 +1055,7 @@ execute_tail_calls (void)
   return tree_optimize_tail_calls_1 (true);
 }
 
-struct gimple_opt_pass pass_tail_recursion = 
+struct gimple_opt_pass pass_tail_recursion =
 {
  {
   GIMPLE_PASS,
@@ -1011,7 +1065,7 @@ struct gimple_opt_pass pass_tail_recursion =
   NULL,					/* sub */
   NULL,					/* next */
   0,					/* static_pass_number */
-  0,					/* tv_id */
+  TV_NONE,				/* tv_id */
   PROP_cfg | PROP_ssa,			/* properties_required */
   0,					/* properties_provided */
   0,					/* properties_destroyed */
@@ -1020,7 +1074,7 @@ struct gimple_opt_pass pass_tail_recursion =
  }
 };
 
-struct gimple_opt_pass pass_tail_calls = 
+struct gimple_opt_pass pass_tail_calls =
 {
  {
   GIMPLE_PASS,
@@ -1030,8 +1084,8 @@ struct gimple_opt_pass pass_tail_calls =
   NULL,					/* sub */
   NULL,					/* next */
   0,					/* static_pass_number */
-  0,					/* tv_id */
-  PROP_cfg | PROP_ssa | PROP_alias,	/* properties_required */
+  TV_NONE,				/* tv_id */
+  PROP_cfg | PROP_ssa,			/* properties_required */
   0,					/* properties_provided */
   0,					/* properties_destroyed */
   0,					/* todo_flags_start */