/* Tail call optimization on trees.
- Copyright (C) 2003, 2004, 2005 Free Software Foundation, Inc.
+ Copyright (C) 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2, or (at your option)
+the Free Software Foundation; either version 3, or (at your option)
any later version.
GCC is distributed in the hope that it will be useful,
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
-along with GCC; see the file COPYING. If not, write to
-the Free Software Foundation, 51 Franklin Street, Fifth Floor,
-Boston, MA 02110-1301, USA. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "tree-pass.h"
#include "flags.h"
#include "langhooks.h"
+#include "dbgcnt.h"
/* The file implements the tail recursion elimination. It is also used to
analyze the tail calls in general, passing the results to the rtl level
/* Accumulator optimizations will reverse the order of operations.
We can only do that for floating-point types if we're assuming
that addition and multiplication are associative. */
- if (!flag_unsafe_math_optimizations)
+ if (!flag_associative_math)
if (FLOAT_TYPE_P (TREE_TYPE (DECL_RESULT (current_function_decl))))
return false;
*ass_var = dest;
return true;
- /* TODO -- Handle other codes (NEGATE_EXPR, MINUS_EXPR). */
+ /* TODO -- Handle other codes (NEGATE_EXPR, MINUS_EXPR, POINTER_PLUS_EXPR). */
default:
return false;
static void
find_tail_calls (basic_block bb, struct tailcall **ret)
{
- tree ass_var, ret_var, stmt, func, param, args, call = NULL_TREE;
+ tree ass_var, ret_var, stmt, func, param, call = NULL_TREE;
block_stmt_iterator bsi, absi;
bool tail_recursion;
struct tailcall *nw;
/* If the statement has virtual or volatile operands, fail. */
ann = stmt_ann (stmt);
if (!ZERO_SSA_OPERANDS (stmt, (SSA_OP_VUSE | SSA_OP_VIRTUAL_DEFS))
- || ann->has_volatile_ops)
+ || ann->has_volatile_ops
+ || (!gimple_aliases_computed_p (cfun) && ann->references_memory))
return;
}
func = get_callee_fndecl (call);
if (func == current_function_decl)
{
- for (param = DECL_ARGUMENTS (func), args = TREE_OPERAND (call, 1);
- param && args;
- param = TREE_CHAIN (param), args = TREE_CHAIN (args))
+ call_expr_arg_iterator iter;
+ tree arg;
+ for (param = DECL_ARGUMENTS (func),
+ arg = first_call_expr_arg (call, &iter);
+ param && arg;
+ param = TREE_CHAIN (param), arg = next_call_expr_arg (&iter))
{
- tree arg = TREE_VALUE (args);
if (param != arg)
{
/* Make sure there are no problems with copying. The parameter
equivalent types. The latter requirement could be relaxed if
we emitted a suitable type conversion statement. */
if (!is_gimple_reg_type (TREE_TYPE (param))
- || !lang_hooks.types_compatible_p (TREE_TYPE (param),
- TREE_TYPE (arg)))
+ || !useless_type_conversion_p (TREE_TYPE (param),
+ TREE_TYPE (arg)))
break;
/* The parameter should be a real operand, so that phi node
break;
}
}
- if (!args && !param)
+ if (!arg && !param)
tail_recursion = true;
}
var = m_acc;
else
{
- stmt = build2 (GIMPLE_MODIFY_STMT, ret_type, NULL_TREE,
- build2 (MULT_EXPR, ret_type, m_acc, a));
+ stmt = build_gimple_modify_stmt (NULL_TREE,
+ build2 (MULT_EXPR, ret_type,
+ m_acc, a));
tmp = create_tmp_var (ret_type, "acc_tmp");
add_referenced_var (tmp);
else
var = a;
- stmt = build2 (GIMPLE_MODIFY_STMT, ret_type, NULL_TREE,
- build2 (PLUS_EXPR, ret_type, a_acc, var));
+ stmt = build_gimple_modify_stmt (NULL_TREE, build2 (PLUS_EXPR, ret_type,
+ a_acc, var));
var = make_ssa_name (SSA_NAME_VAR (a_acc), stmt);
GIMPLE_STMT_OPERAND (stmt, 0) = var;
bsi_insert_after (&bsi, stmt, BSI_NEW_STMT);
if (m)
{
- stmt = build2 (GIMPLE_MODIFY_STMT, ret_type, NULL_TREE,
- build2 (MULT_EXPR, ret_type, m_acc, m));
+ stmt = build_gimple_modify_stmt (NULL_TREE,
+ build2 (MULT_EXPR, ret_type,
+ m_acc, m));
var = make_ssa_name (SSA_NAME_VAR (m_acc), stmt);
GIMPLE_STMT_OPERAND (stmt, 0) = var;
bsi_insert_after (&bsi, stmt, BSI_NEW_STMT);
{
tree ret_stmt = last_stmt (bb), ret_var, var, stmt, tmp;
tree ret_type = TREE_TYPE (DECL_RESULT (current_function_decl));
+ tree *ret_op;
block_stmt_iterator bsi = bsi_last (bb);
gcc_assert (TREE_CODE (ret_stmt) == RETURN_EXPR);
if (TREE_CODE (ret_var) == GIMPLE_MODIFY_STMT)
{
- ret_var->base.ann = (tree_ann_t) stmt_ann (ret_stmt);
- bsi_replace (&bsi, ret_var, true);
- SSA_NAME_DEF_STMT (GIMPLE_STMT_OPERAND (ret_var, 0)) = ret_var;
- ret_var = GIMPLE_STMT_OPERAND (ret_var, 0);
- ret_stmt = build1 (RETURN_EXPR, TREE_TYPE (ret_stmt), ret_var);
- bsi_insert_after (&bsi, ret_stmt, BSI_NEW_STMT);
+ ret_op = &GIMPLE_STMT_OPERAND (ret_var, 1);
+ ret_var = *ret_op;
}
+ else
+ ret_op = &TREE_OPERAND (ret_stmt, 0);
if (m)
{
- stmt = build2 (GIMPLE_MODIFY_STMT, ret_type, NULL_TREE,
- build2 (MULT_EXPR, ret_type, m_acc, ret_var));
+ stmt = build_gimple_modify_stmt (NULL_TREE,
+ build2 (MULT_EXPR, ret_type,
+ m_acc, ret_var));
tmp = create_tmp_var (ret_type, "acc_tmp");
add_referenced_var (tmp);
if (a)
{
- stmt = build2 (GIMPLE_MODIFY_STMT, ret_type, NULL_TREE,
- build2 (PLUS_EXPR, ret_type, a_acc, var));
+ stmt = build_gimple_modify_stmt (NULL_TREE,
+ build2 (PLUS_EXPR, ret_type,
+ a_acc, var));
tmp = create_tmp_var (ret_type, "acc_tmp");
add_referenced_var (tmp);
bsi_insert_before (&bsi, stmt, BSI_SAME_STMT);
}
- TREE_OPERAND (ret_stmt, 0) = var;
+ *ret_op = var;
update_stmt (ret_stmt);
}
static void
eliminate_tail_call (struct tailcall *t)
{
- tree param, stmt, args, rslt, call;
+ tree param, stmt, rslt, call;
+ tree arg;
+ call_expr_arg_iterator iter;
basic_block bb, first;
edge e;
tree phi;
/* Add phi node entries for arguments. The ordering of the phi nodes should
be the same as the ordering of the arguments. */
for (param = DECL_ARGUMENTS (current_function_decl),
- args = TREE_OPERAND (stmt, 1),
- phi = phi_nodes (first);
+ arg = first_call_expr_arg (stmt, &iter),
+ phi = phi_nodes (first);
param;
- param = TREE_CHAIN (param),
- args = TREE_CHAIN (args))
+ param = TREE_CHAIN (param), arg = next_call_expr_arg (&iter))
{
if (!arg_needs_copy_p (param))
continue;
gcc_assert (param == SSA_NAME_VAR (PHI_RESULT (phi)));
- add_phi_arg (phi, TREE_VALUE (args), e);
+ add_phi_arg (phi, arg, e);
phi = PHI_CHAIN (phi);
}
if (!is_gimple_reg (var) && gimple_default_def (cfun, var) != NULL_TREE)
mark_sym_for_renaming (var);
}
-
- update_ssa (TODO_update_ssa_only_virtuals);
}
/* Optimizes the tailcall described by T. If OPT_TAILCALLS is true, also
/* Optimizes tail calls in the function, turning the tail recursion
into iteration. */
-static void
+static unsigned int
tree_optimize_tail_calls_1 (bool opt_tailcalls)
{
edge e;
edge_iterator ei;
if (!suitable_for_tail_opt_p ())
- return;
+ return 0;
if (opt_tailcalls)
opt_tailcalls = suitable_for_tail_call_opt_p ();
}
if (changed)
- {
- free_dominance_info (CDI_DOMINATORS);
- cleanup_tree_cfg ();
- }
+ free_dominance_info (CDI_DOMINATORS);
if (phis_constructed)
add_virtual_phis ();
+ if (changed)
+ return TODO_cleanup_cfg | TODO_update_ssa_only_virtuals;
+ return 0;
}
static unsigned int
execute_tail_recursion (void)
{
- tree_optimize_tail_calls_1 (false);
- return 0;
+ return tree_optimize_tail_calls_1 (false);
}
static bool
gate_tail_calls (void)
{
- return flag_optimize_sibling_calls != 0;
+ return flag_optimize_sibling_calls != 0 && dbg_cnt (tail_call);
}
static unsigned int
execute_tail_calls (void)
{
- tree_optimize_tail_calls_1 (true);
- return 0;
+ return tree_optimize_tail_calls_1 (true);
}
-struct tree_opt_pass pass_tail_recursion =
+struct gimple_opt_pass pass_tail_recursion =
{
+ {
+ GIMPLE_PASS,
"tailr", /* name */
gate_tail_calls, /* gate */
execute_tail_recursion, /* execute */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
- TODO_dump_func | TODO_verify_ssa, /* todo_flags_finish */
- 0 /* letter */
+ TODO_dump_func | TODO_verify_ssa /* todo_flags_finish */
+ }
};
-struct tree_opt_pass pass_tail_calls =
+struct gimple_opt_pass pass_tail_calls =
{
+ {
+ GIMPLE_PASS,
"tailc", /* name */
gate_tail_calls, /* gate */
execute_tail_calls, /* execute */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
- TODO_dump_func | TODO_verify_ssa, /* todo_flags_finish */
- 0 /* letter */
+ TODO_dump_func | TODO_verify_ssa /* todo_flags_finish */
+ }
};
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