/*
- * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved.
- *
* This file is part of libFirm.
- *
- * This file may be distributed and/or modified under the terms of the
- * GNU General Public License version 2 as published by the Free Software
- * Foundation and appearing in the file LICENSE.GPL included in the
- * packaging of this file.
- *
- * Licensees holding valid libFirm Professional Edition licenses may use
- * this file in accordance with the libFirm Commercial License.
- * Agreement provided with the Software.
- *
- * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
- * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE.
+ * Copyright (C) 2012 University of Karlsruhe.
*/
/**
* [Trapp:99], Chapter 5.2.1.2.
* @author Goetz Lindenmaier
* @date 7.2002
- * @version $Id$
*/
#include "config.h"
#include "irgwalk.h"
#include "irprog_t.h"
#include "irdump.h"
-
-#define NO_CFLOOPS_WITHOUT_HEAD 1
+#include "ircons_t.h"
/** The outermost graph the scc is computed for */
static ir_graph *outermost_ir_graph;
/** Counter to generate depth first numbering of visited nodes. */
static int current_dfn = 1;
-static int max_loop_depth = 0;
-
-void link_to_reg_end(ir_node *n, void *env);
-
-/**********************************************************************/
-/* Node attributes **/
-/**********************************************************************/
-
/**********************************************************************/
/* Node attributes needed for the construction. **/
/**********************************************************************/
*/
static inline void mark_irn_in_stack(ir_node *n)
{
- scc_info *info = get_irn_link(n);
+ scc_info *info = (scc_info*) get_irn_link(n);
info->in_stack = 1;
}
*/
static inline void mark_irn_not_in_stack(ir_node *n)
{
- scc_info *info = get_irn_link(n);
+ scc_info *info = (scc_info*) get_irn_link(n);
info->in_stack = 0;
}
*/
static inline int irn_is_in_stack(ir_node *n)
{
- scc_info *info = get_irn_link(n);
+ scc_info *info = (scc_info*) get_irn_link(n);
return info->in_stack;
}
*/
static inline void set_irn_uplink(ir_node *n, int uplink)
{
- scc_info *info = get_irn_link(n);
+ scc_info *info = (scc_info*) get_irn_link(n);
info->uplink = uplink;
}
*/
static inline int get_irn_uplink(ir_node *n)
{
- scc_info *info = get_irn_link(n);
+ scc_info *info = (scc_info*) get_irn_link(n);
return info->uplink;
}
*/
static inline void set_irn_dfn(ir_node *n, int dfn)
{
- scc_info *info = get_irn_link(n);
+ scc_info *info = (scc_info*) get_irn_link(n);
info->dfn = dfn;
}
*/
static inline int get_irn_dfn(ir_node *n)
{
- scc_info *info = get_irn_link(n);
+ scc_info *info = (scc_info*) get_irn_link(n);
return info->dfn;
}
/** An IR-node stack */
static ir_node **stack = NULL;
/** The top (index) of the IR-node stack */
-static int tos = 0;
+static size_t tos = 0;
/**
* Initializes the IR-node stack
static inline void push(ir_node *n)
{
if (tos == ARR_LEN(stack)) {
- int nlen = ARR_LEN(stack) * 2;
+ size_t nlen = ARR_LEN(stack) * 2;
ARR_RESIZE(ir_node *, stack, nlen);
}
stack[tos++] = n;
can't they have two loops as sons? Does it never get that far? ) */
static void close_loop(ir_loop *l)
{
- int last = get_loop_n_elements(l) - 1;
+ size_t last = get_loop_n_elements(l) - 1;
loop_element lelement = get_loop_element(l, last);
ir_loop *last_son = lelement.son;
static ir_loop *new_loop(void)
{
ir_loop *father = current_loop;
- ir_loop *son = alloc_loop(father, outermost_ir_graph->obst);
+ ir_loop *son = alloc_loop(father, get_irg_obstack(outermost_ir_graph));
- if (son->depth > max_loop_depth) max_loop_depth = son->depth;
current_loop = son;
return father;
}
*/
static inline void init_node(ir_node *n, void *env)
{
- struct obstack *obst = env;
+ struct obstack *obst = (struct obstack*) env;
if (is_Block(n))
set_irn_link(n, new_scc_info(obst));
clear_backedges(n);
finish_stack();
}
-#ifdef INTERPROCEDURAL_VIEW
-/**
- * Initializes the scc algorithm for the interprocedural case.
- */
-static inline void init_ip_scc(struct obstack *obst)
-{
- init_scc_common();
- cg_walk(init_node, NULL, obst);
-
-#if EXPERIMENTAL_CFLOOP_TREE
- cg_walk(link_to_reg_end, NULL, NULL);
-#endif
-}
-#endif
-
-/**
- * Condition for breaking the recursion: n is the block
- * that gets the initial control flow from the Start node.
- */
-static int is_outermost_StartBlock(ir_node *n)
-{
- /* Test whether this is the outermost Start node. If so
- recursion must end. */
- assert(is_Block(n));
- if (get_Block_n_cfgpreds(n) == 1 &&
- is_Start(skip_Proj(get_Block_cfgpred(n, 0))) &&
- get_Block_cfgpred_block(n, 0) == n) {
- return 1;
- }
- return 0;
-}
-
/** Returns non-zero if n is a loop header, i.e., it is a Block node
* and has predecessors within the cfloop and out of the cfloop.
*
*/
static int is_head(ir_node *n, ir_node *root)
{
- int i, arity;
int some_outof_loop = 0, some_in_loop = 0;
(void) root;
- assert(is_Block(n));
-
- if (!is_outermost_StartBlock(n)) {
- arity = get_Block_n_cfgpreds(n);
- for (i = 0; i < arity; i++) {
- ir_node *pred = get_Block_cfgpred_block(n, i);
- /* ignore Bad control flow: it cannot happen */
- if (is_Bad(pred))
- continue;
- if (is_backedge(n, i))
- continue;
- if (!irn_is_in_stack(pred)) {
- some_outof_loop = 1;
- } else {
- assert(get_irn_uplink(pred) >= get_irn_uplink(root));
- some_in_loop = 1;
- }
+ int const arity = get_Block_n_cfgpreds(n);
+ for (int i = 0; i < arity; i++) {
+ ir_node *pred = get_Block_cfgpred_block(n, i);
+ /* ignore Bad control flow: it cannot happen */
+ if (is_Bad(pred))
+ continue;
+ if (is_backedge(n, i))
+ continue;
+ if (!irn_is_in_stack(pred)) {
+ some_outof_loop = 1;
+ } else {
+ assert(get_irn_uplink(pred) >= get_irn_uplink(root));
+ some_in_loop = 1;
}
}
return some_outof_loop & some_in_loop;
*/
static int is_endless_head(ir_node *n, ir_node *root)
{
- int i, arity;
int none_outof_loop = 1, some_in_loop = 0;
(void) root;
- assert(is_Block(n));
/* Test for legal loop header: Block, Phi, ... */
- if (!is_outermost_StartBlock(n)) {
- arity = get_Block_n_cfgpreds(n);
- for (i = 0; i < arity; i++) {
- ir_node *pred = get_Block_cfgpred_block(n, i);
- /* ignore Bad control flow: it cannot happen */
- if (is_Bad(pred))
- continue;
- if (is_backedge(n, i))
- continue;
- if (!irn_is_in_stack(pred)) {
- none_outof_loop = 0;
- } else {
- assert(get_irn_uplink(pred) >= get_irn_uplink(root));
- some_in_loop = 1;
- }
+ int const arity = get_Block_n_cfgpreds(n);
+ for (int i = 0; i < arity; i++) {
+ ir_node *pred = get_Block_cfgpred_block(n, i);
+ /* ignore Bad control flow: it cannot happen */
+ if (is_Bad(pred))
+ continue;
+ if (is_backedge(n, i))
+ continue;
+ if (!irn_is_in_stack(pred)) {
+ none_outof_loop = 0;
+ } else {
+ assert(get_irn_uplink(pred) >= get_irn_uplink(root));
+ some_in_loop = 1;
}
}
return none_outof_loop && some_in_loop;
{
int i, index = -2, min = -1;
- if (!is_outermost_StartBlock(n)) {
- int arity = get_Block_n_cfgpreds(n);
- for (i = 0; i < arity; i++) {
- ir_node *pred = get_Block_cfgpred_block(n, i);
- /* ignore Bad control flow: it cannot happen */
- if (is_Bad(pred))
- continue;
- if (is_backedge(n, i) || !irn_is_in_stack(pred))
- continue;
- if (get_irn_dfn(pred) >= limit && (min == -1 || get_irn_dfn(pred) < min)) {
- index = i;
- min = get_irn_dfn(pred);
- }
+ int arity = get_Block_n_cfgpreds(n);
+ for (i = 0; i < arity; i++) {
+ ir_node *pred = get_Block_cfgpred_block(n, i);
+ /* ignore Bad control flow: it cannot happen */
+ if (is_Bad(pred))
+ continue;
+ if (is_backedge(n, i) || !irn_is_in_stack(pred))
+ continue;
+ if (get_irn_dfn(pred) >= limit && (min == -1 || get_irn_dfn(pred) < min)) {
+ index = i;
+ min = get_irn_dfn(pred);
}
}
return index;
{
int i, index = -2, max = -1;
- if (!is_outermost_StartBlock(n)) {
- int arity = get_Block_n_cfgpreds(n);
- for (i = 0; i < arity; i++) {
- ir_node *pred = get_Block_cfgpred_block(n, i);
- /* ignore Bad control flow: it cannot happen */
- if (is_Bad(pred))
- continue;
- if (is_backedge(n, i) || !irn_is_in_stack(pred))
- continue;
- if (get_irn_dfn(pred) > max) {
- index = i;
- max = get_irn_dfn(pred);
- }
+ int arity = get_Block_n_cfgpreds(n);
+ for (i = 0; i < arity; i++) {
+ ir_node *pred = get_Block_cfgpred_block(n, i);
+ /* ignore Bad control flow: it cannot happen */
+ if (is_Bad(pred))
+ continue;
+ if (is_backedge(n, i) || !irn_is_in_stack(pred))
+ continue;
+ if (get_irn_dfn(pred) > max) {
+ index = i;
+ max = get_irn_dfn(pred);
}
}
return index;
static ir_node *find_tail(ir_node *n)
{
ir_node *m;
- int i, res_index = -2;
+ int res_index = -2;
+ size_t i;
- m = stack[tos-1]; /* tos = top of stack */
+ m = stack[tos - 1]; /* tos = top of stack */
if (is_head(m, n)) {
res_index = smallest_dfn_pred(m, 0);
if ((res_index == -2) && /* no smallest dfn pred found. */
} else {
if (m == n)
return NULL;
- for (i = tos-2; i >= 0; --i) {
-
- m = stack[i];
+ for (i = tos - 1; i != 0;) {
+ m = stack[--i];
if (is_head(m, n)) {
res_index = smallest_dfn_pred(m, get_irn_dfn(m) + 1);
if (res_index == -2) /* no smallest dfn pred found. */
res_index = largest_dfn_pred(m);
if ((m == n) && (res_index == -2)) {
- i = -1;
+ i = (size_t)-1;
}
break;
}
/* We should not walk past our selves on the stack: The upcoming nodes
are not in this loop. We assume a loop not reachable from Start. */
if (m == n) {
- i = -1;
+ i = (size_t)-1;
break;
}
}
- if (i < 0) {
+ if (i == (size_t)-1) {
/* A dead loop not reachable from Start. */
- for (i = tos-2; i >= 0; --i) {
- m = stack[i];
+ for (i = tos - 1; i != 0;) {
+ m = stack[--i];
if (is_endless_head(m, n)) {
res_index = smallest_dfn_pred (m, get_irn_dfn(m) + 1);
if (res_index == -2) /* no smallest dfn pred found. */
assert(res_index > -2);
set_backedge(m, res_index);
- return is_outermost_StartBlock(n) ? NULL : get_Block_cfgpred_block(m, res_index);
+ return get_Block_cfgpred_block(m, res_index);
}
/**
*/
static void cfscc(ir_node *n)
{
+ int arity;
int i;
assert(is_Block(n));
++current_dfn;
push(n);
- if (!is_outermost_StartBlock(n)) {
- int arity = get_Block_n_cfgpreds(n);
-
- for (i = 0; i < arity; i++) {
- ir_node *m;
-
- if (is_backedge(n, i))
- continue;
- m = get_Block_cfgpred_block(n, i);
- /* ignore Bad control flow: it cannot happen */
- if (is_Bad(m))
- continue;
-
- cfscc(m);
- if (irn_is_in_stack(m)) {
- /* Uplink of m is smaller if n->m is a backedge.
- Propagate the uplink to mark the cfloop. */
- if (get_irn_uplink(m) < get_irn_uplink(n))
- set_irn_uplink(n, get_irn_uplink(m));
- }
+ arity = get_Block_n_cfgpreds(n);
+
+ for (i = 0; i < arity; i++) {
+ ir_node *m;
+
+ if (is_backedge(n, i))
+ continue;
+ m = get_Block_cfgpred_block(n, i);
+ /* ignore Bad control flow: it cannot happen */
+ if (is_Bad(m))
+ continue;
+
+ cfscc(m);
+ if (irn_is_in_stack(m)) {
+ /* Uplink of m is smaller if n->m is a backedge.
+ Propagate the uplink to mark the cfloop. */
+ if (get_irn_uplink(m) < get_irn_uplink(n))
+ set_irn_uplink(n, get_irn_uplink(m));
}
}
Next actions: Open a new cfloop on the cfloop tree and
try to find inner cfloops */
-#if NO_CFLOOPS_WITHOUT_HEAD
-
/* This is an adaption of the algorithm from fiasco / optscc to
* avoid cfloops without Block or Phi as first node. This should
* severely reduce the number of evaluations of nodes to detect
close = 0;
}
-#else
-
- ir_loop *l = new_loop();
-
-#endif
-
/* Remove the cfloop from the stack ... */
pop_scc_unmark_visit(n);
cfscc(tail);
assert(irn_visited(n));
-#if NO_CFLOOPS_WITHOUT_HEAD
if (close)
-#endif
close_loop(l);
} else {
/* AS: No cfloop head was found, that is we have straight line code.
}
}
-/* Constructs control flow backedge information for irg. */
-int construct_cf_backedges(ir_graph *irg)
+void construct_cf_backedges(ir_graph *irg)
{
- ir_graph *rem = current_ir_graph;
ir_loop *head_rem;
ir_node *end = get_irg_end(irg);
struct obstack temp;
int i;
- assert(!get_interprocedural_view() &&
- "use construct_ip_cf_backedges()");
- max_loop_depth = 0;
-
- current_ir_graph = irg;
outermost_ir_graph = irg;
obstack_init(&temp);
obstack_free(&temp, NULL);
assert(head_rem == current_loop);
- mature_loops(current_loop, irg->obst);
+ mature_loops(current_loop, get_irg_obstack(irg));
set_irg_loop(irg, current_loop);
- set_irg_loopinfo_state(irg, loopinfo_cf_consistent);
- assert(get_irg_loop(irg)->kind == k_ir_loop);
-
- current_ir_graph = rem;
- return max_loop_depth;
-}
-
-void assure_cf_loop(ir_graph *irg)
-{
- irg_loopinfo_state state = get_irg_loopinfo_state(irg);
-
- if (state != loopinfo_cf_consistent)
- construct_cf_backedges(irg);
-}
-
-#ifdef INTERPROCEDURAL_VIEW
-int construct_ip_cf_backedges (void)
-{
- ir_graph *rem = current_ir_graph;
- int rem_ipv = get_interprocedural_view();
- struct obstack temp;
- int i;
-
- assert(get_irp_ip_view_state() == ip_view_valid);
- max_loop_depth = 0;
- outermost_ir_graph = get_irp_main_irg();
-
- obstack_init(&temp);
- init_ip_scc(&temp);
-
- current_loop = NULL;
- new_loop(); /* sets current_loop */
- set_interprocedural_view(1);
-
- inc_max_irg_visited();
- for (i = 0; i < get_irp_n_irgs(); i++)
- set_irg_visited(get_irp_irg(i), get_max_irg_visited());
-
- /** We have to start the walk at the same nodes as cg_walk. **/
- /* Walk starting at unreachable procedures. Only these
- * have End blocks visible in interprocedural view. */
- for (i = 0; i < get_irp_n_irgs(); i++) {
- ir_node *sb;
- current_ir_graph = get_irp_irg(i);
-
- sb = get_irg_start_block(current_ir_graph);
-
- if ((get_Block_n_cfgpreds(sb) > 1) ||
- (get_nodes_block(get_Block_cfgpred(sb, 0)) != sb)) continue;
-
- cfscc(get_irg_end_block(current_ir_graph));
- }
-
- /* Check whether we walked all procedures: there could be procedures
- with cyclic calls but no call from the outside. */
- for (i = 0; i < get_irp_n_irgs(); i++) {
- ir_node *sb;
- current_ir_graph = get_irp_irg(i);
-
- /* Test start block: if inner procedure end and end block are not
- * visible and therefore not marked. */
- sb = get_irg_start_block(current_ir_graph);
- if (get_irn_visited(sb) < get_irg_visited(current_ir_graph)) cfscc(sb);
- }
-
- /* Walk all endless cfloops in inner procedures.
- * We recognize an inner procedure if the End node is not visited. */
- for (i = 0; i < get_irp_n_irgs(); i++) {
- ir_node *e;
- current_ir_graph = get_irp_irg(i);
-
- e = get_irg_end(current_ir_graph);
- if (get_irn_visited(e) < get_irg_visited(current_ir_graph)) {
- int j;
- /* Don't visit the End node. */
- for (j = 0; j < get_End_n_keepalives(e); j++) {
- ir_node *el = get_End_keepalive(e, j);
- if (is_Block(el)) cfscc(el);
- }
- }
- }
-
- set_irg_loop(outermost_ir_graph, current_loop);
- set_irg_loopinfo_state(current_ir_graph, loopinfo_cf_ip_consistent);
- assert(get_irg_loop(outermost_ir_graph)->kind == k_ir_loop);
-
- obstack_free(&temp, NULL);
- current_ir_graph = rem;
- set_interprocedural_view(rem_ipv);
- return max_loop_depth;
-}
-#endif
-
-/**
- * Clear the intra- and the interprocedural
- * backedge information pf a block.
- */
-static void reset_backedges(ir_node *block)
-{
- int rem;
-
- assert(is_Block(block));
-#ifdef INTERPROCEDURAL_VIEW
- rem = get_interprocedural_view();
- set_interprocedural_view(1);
- clear_backedges(block);
- set_interprocedural_view(0);
- clear_backedges(block);
- set_interprocedural_view(rem);
-#else
- (void) rem;
- clear_backedges(block);
-#endif
-}
-
-/**
- * Reset all backedges of the first block of
- * a loop as well as all loop info for all nodes of this loop.
- * Recurse into all nested loops.
- */
-static void loop_reset_backedges(ir_loop *l)
-{
- int i;
- reset_backedges(get_loop_node(l, 0));
- for (i = 0; i < get_loop_n_nodes(l); ++i)
- set_irn_loop(get_loop_node(l, i), NULL);
- for (i = 0; i < get_loop_n_sons(l); ++i) {
- loop_reset_backedges(get_loop_son(l, i));
- }
-}
-
-/* Removes all cfloop information.
- Resets all backedges */
-void free_cfloop_information(ir_graph *irg)
-{
- ir_loop *loop = get_irg_loop(irg);
- if (loop != NULL) {
- loop_reset_backedges(loop);
- set_irg_loop(irg, NULL);
- }
- set_irg_loopinfo_state(irg, loopinfo_none);
- /* We cannot free the cfloop nodes, they are on the obstack. */
+ add_irg_properties(irg, IR_GRAPH_PROPERTY_CONSISTENT_LOOPINFO);
}
-
-void free_all_cfloop_information(void)
+void assure_loopinfo(ir_graph *irg)
{
- int i;
-#ifdef INTERPROCEDURAL_VIEW
- int rem = get_interprocedural_view();
- set_interprocedural_view(1); /* To visit all filter nodes */
-#endif
- for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
- free_cfloop_information(get_irp_irg(i));
- }
-#ifdef INTERPROCEDURAL_VIEW
- set_interprocedural_view(rem);
-#endif
+ if (irg_has_properties(irg, IR_GRAPH_PROPERTY_CONSISTENT_LOOPINFO))
+ return;
+ construct_cf_backedges(irg);
}
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