/* Callgraph based analysis of static variables.
- Copyright (C) 2004, 2005 Free Software Foundation, Inc.
+ Copyright (C) 2004, 2005, 2007 Free Software Foundation, Inc.
Contributed by Kenneth Zadeck <zadeck@naturalbridge.com>
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) any later
+Software Foundation; either version 3, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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/>. */
/* This file mark functions as being either const (TREE_READONLY) or
- pure (DECL_IS_PURE).
+ pure (DECL_PURE_P). It can also set the a variant of these that
+ are allowed to infinite loop (DECL_LOOPING_CONST_PURE_P).
This must be run after inlining decisions have been made since
otherwise, the local sets will not contain information that is
struct funct_state_d
{
enum pure_const_state_e pure_const_state;
+ bool looping;
bool state_set_in_source;
};
static inline funct_state
get_function_state (struct cgraph_node *node)
{
- struct ipa_dfs_info * info = node->aux;
- return info->aux;
+ struct ipa_dfs_info * info = (struct ipa_dfs_info *) node->aux;
+ return (funct_state) info->aux;
}
/* Check to see if the use (or definition when CHECHING_WRITE is true)
if (lookup_attribute ("used", DECL_ATTRIBUTES (t)))
{
local->pure_const_state = IPA_NEITHER;
+ local->looping = false;
return;
}
if (TREE_THIS_VOLATILE (t))
{
local->pure_const_state = IPA_NEITHER;
+ local->looping = false;
return;
}
are CHECKING_WRITE, this cannot be a pure or constant
function. */
if (checking_write)
- local->pure_const_state = IPA_NEITHER;
+ {
+ local->pure_const_state = IPA_NEITHER;
+ local->looping = false;
+ return;
+ }
if (DECL_EXTERNAL (t) || TREE_PUBLIC (t))
{
static void
check_tree (funct_state local, tree t, bool checking_write)
{
- if ((TREE_CODE (t) == EXC_PTR_EXPR) || (TREE_CODE (t) == FILTER_EXPR))
+ if ((TREE_CODE (t) == EXC_PTR_EXPR) || (TREE_CODE (t) == FILTER_EXPR)
+ || TREE_CODE (t) == SSA_NAME)
return;
+ /* Any tree which is volatile disqualifies thie function from being
+ const or pure. */
+ if (TREE_THIS_VOLATILE (t))
+ {
+ local->pure_const_state = IPA_NEITHER;
+ local->looping = false;
+ return;
+ }
+
while (TREE_CODE (t) == REALPART_EXPR
|| TREE_CODE (t) == IMAGPART_EXPR
|| handled_component_p (t))
/* Any indirect reference that occurs on the lhs
disqualifies the function from being pure or const. Any
- indirect reference to a volatile disqualifies the
- function from being pure or const. Any indirect
- reference that occurs on the rhs disqualifies the
+ indirect reference that occurs on the rhs disqualifies the
function from being const. */
- if (checking_write || TREE_THIS_VOLATILE (t))
- local->pure_const_state = IPA_NEITHER;
+ if (checking_write)
+ {
+ local->pure_const_state = IPA_NEITHER;
+ local->looping = false;
+ return;
+ }
else if (local->pure_const_state == IPA_CONST)
local->pure_const_state = IPA_PURE;
}
static void
check_call (funct_state local, tree call_expr)
{
- int flags = call_expr_flags(call_expr);
- tree operand_list = TREE_OPERAND (call_expr, 1);
+ int flags = call_expr_flags (call_expr);
tree operand;
+ call_expr_arg_iterator iter;
tree callee_t = get_callee_fndecl (call_expr);
struct cgraph_node* callee;
enum availability avail = AVAIL_NOT_AVAILABLE;
- for (operand = operand_list;
- operand != NULL_TREE;
- operand = TREE_CHAIN (operand))
- {
- tree argument = TREE_VALUE (operand);
- check_rhs_var (local, argument);
- }
+ FOR_EACH_CALL_EXPR_ARG (operand, iter, call_expr)
+ check_rhs_var (local, operand);
/* The const and pure flags are set by a variety of places in the
compiler (including here). If someone has already set the flags
/* When bad things happen to bad functions, they cannot be const
or pure. */
if (setjmp_call_p (callee_t))
- local->pure_const_state = IPA_NEITHER;
+ {
+ local->pure_const_state = IPA_NEITHER;
+ local->looping = false;
+ }
if (DECL_BUILT_IN_CLASS (callee_t) == BUILT_IN_NORMAL)
switch (DECL_FUNCTION_CODE (callee_t))
case BUILT_IN_LONGJMP:
case BUILT_IN_NONLOCAL_GOTO:
local->pure_const_state = IPA_NEITHER;
+ local->looping = false;
break;
default:
break;
int *walk_subtrees,
void *data)
{
- struct cgraph_node *fn = data;
+ struct cgraph_node *fn = (struct cgraph_node *) data;
tree t = *tp;
funct_state local = get_function_state (fn);
*walk_subtrees = 0;
break;
- case MODIFY_EXPR:
+ case GIMPLE_MODIFY_STMT:
{
/* First look on the lhs and see what variable is stored to */
- tree lhs = TREE_OPERAND (t, 0);
- tree rhs = TREE_OPERAND (t, 1);
+ tree lhs = GIMPLE_STMT_OPERAND (t, 0);
+ tree rhs = GIMPLE_STMT_OPERAND (t, 1);
check_lhs_var (local, lhs);
/* For the purposes of figuring out what the cast affects */
case ADDR_EXPR:
check_rhs_var (local, rhs);
break;
- case CALL_EXPR:
+ default:
+ break;
+ }
+ break;
+ case tcc_vl_exp:
+ switch (TREE_CODE (rhs))
+ {
+ case CALL_EXPR:
check_call (local, rhs);
break;
default:
case LABEL_EXPR:
if (DECL_NONLOCAL (TREE_OPERAND (t, 0)))
/* Target of long jump. */
- local->pure_const_state = IPA_NEITHER;
+ {
+ local->pure_const_state = IPA_NEITHER;
+ local->looping = false;
+ }
break;
case CALL_EXPR:
{
funct_state l = XCNEW (struct funct_state_d);
tree decl = fn->decl;
- struct ipa_dfs_info * w_info = fn->aux;
+ struct ipa_dfs_info * w_info = (struct ipa_dfs_info *) fn->aux;
w_info->aux = l;
l->pure_const_state = IPA_CONST;
l->state_set_in_source = false;
+ if (DECL_LOOPING_CONST_OR_PURE_P (decl))
+ l->looping = true;
+ else
+ l->looping = false;
/* If this function does not return normally or does not bind local,
do not touch this unless it has been marked as const or pure by the
l->pure_const_state = IPA_CONST;
l->state_set_in_source = true;
}
- if (DECL_IS_PURE (decl))
+ if (DECL_PURE_P (decl))
{
l->pure_const_state = IPA_PURE;
l->state_set_in_source = true;
walk_tree (bsi_stmt_ptr (bsi), scan_function,
fn, visited_nodes);
if (l->pure_const_state == IPA_NEITHER)
- return;
+ goto end;
}
}
pop_cfun ();
}
}
+
+end:
+ if (dump_file)
+ {
+ fprintf (dump_file, "after local analysis of %s with initial value = %d\n ",
+ cgraph_node_name (fn),
+ l->pure_const_state);
+ }
}
\f
struct cgraph_node *w;
struct cgraph_node **order =
XCNEWVEC (struct cgraph_node *, cgraph_n_nodes);
- int order_pos = order_pos = ipa_utils_reduced_inorder (order, true, false);
+ int order_pos = ipa_utils_reduced_inorder (order, true, false);
int i;
struct ipa_dfs_info * w_info;
for (i = 0; i < order_pos; i++ )
{
enum pure_const_state_e pure_const_state = IPA_CONST;
+ bool looping = false;
+ int count = 0;
node = order[i];
/* Find the worst state for any node in the cycle. */
if (pure_const_state < w_l->pure_const_state)
pure_const_state = w_l->pure_const_state;
+ if (w_l->looping)
+ looping = true;
+
if (pure_const_state == IPA_NEITHER)
break;
if (!w_l->state_set_in_source)
{
struct cgraph_edge *e;
+ count++;
+
+ if (count > 1)
+ looping = true;
+
for (e = w->callees; e; e = e->next_callee)
{
struct cgraph_node *y = e->callee;
/* Only look at the master nodes and skip external nodes. */
y = cgraph_master_clone (y);
+
+ if (w == y)
+ looping = true;
if (y)
{
funct_state y_l = get_function_state (y);
pure_const_state = y_l->pure_const_state;
if (pure_const_state == IPA_NEITHER)
break;
+ if (y_l->looping)
+ looping = true;
}
}
}
- w_info = w->aux;
+ w_info = (struct ipa_dfs_info *) w->aux;
w = w_info->next_cycle;
}
{
case IPA_CONST:
TREE_READONLY (w->decl) = 1;
+ DECL_LOOPING_CONST_OR_PURE_P (w->decl) = looping;
if (dump_file)
- fprintf (dump_file, "Function found to be const: %s\n",
+ fprintf (dump_file, "Function found to be %sconst: %s\n",
+ looping ? "looping " : "",
lang_hooks.decl_printable_name(w->decl, 2));
break;
case IPA_PURE:
- DECL_IS_PURE (w->decl) = 1;
+ DECL_PURE_P (w->decl) = 1;
+ DECL_LOOPING_CONST_OR_PURE_P (w->decl) = looping;
if (dump_file)
- fprintf (dump_file, "Function found to be pure: %s\n",
+ fprintf (dump_file, "Function found to be %spure: %s\n",
+ looping ? "looping " : "",
lang_hooks.decl_printable_name(w->decl, 2));
break;
break;
}
}
- w_info = w->aux;
+ w_info = (struct ipa_dfs_info *) w->aux;
w = w_info->next_cycle;
}
}
/* Get rid of the aux information. */
if (node->aux)
{
- w_info = node->aux;
+ w_info = (struct ipa_dfs_info *) node->aux;
if (w_info->aux)
free (w_info->aux);
free (node->aux);
&& !(errorcount || sorrycount));
}
-struct tree_opt_pass pass_ipa_pure_const =
+struct simple_ipa_opt_pass pass_ipa_pure_const =
{
+ {
+ SIMPLE_IPA_PASS,
"pure-const", /* name */
gate_pure_const, /* gate */
static_execute, /* execute */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
- 0, /* todo_flags_finish */
- 0 /* letter */
+ 0 /* todo_flags_finish */
+ }
};
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