#include "irdump.h"
-ir_graph *outermost_ir_graph; /* The outermost graph the scc is computed
- for */
+/* A variant of the loop tree that avoids loops without head.
+ This reduces the depth of the loop tree. */
+#define NO_LOOPS_WITHOUT_HEAD 1
+
+
+INLINE void add_loop_son(ir_loop *loop, ir_loop *son);
+
+INLINE void add_loop_node(ir_loop *loop, ir_node *n);
+
+static ir_graph *outermost_ir_graph; /* The outermost graph the scc is computed
+ for */
static ir_loop *current_loop; /* Current loop construction is working
- on. */
+ on. */
static int loop_node_cnt = 0; /* Counts the number of allocated loop nodes.
- Each loop node gets a unique number.
- What for? ev. remove. @@@ */
+ Each loop node gets a unique number.
+ What for? ev. remove. @@@ */
static int current_dfn = 1; /* Counter to generate depth first numbering
- of visited nodes. */
+ of visited nodes. */
+
+static int max_loop_depth = 0;
void link_to_reg_end (ir_node *n, void *env);
void set_projx_link(ir_node *cb_projx, ir_node *end_projx);
/* Node attributes **/
/**********************************************************************/
-/* A map to get from irnodes to loop nodes. */
-static pmap *node_loop_map = NULL;
-
/**********************************************************************/
/* Node attributes needed for the construction. **/
/**********************************************************************/
return ((scc_info *)n->link)->dfn;
}
-#if 0
-/* Replaced node loop map by real field as hash access dominates runtime
- * of the algorithm. ! */
-/* Uses temporary information to set the loop */
-INLINE void
-set_irn_loop (ir_node *n, ir_loop* loop) {
- assert(node_loop_map && "not initialized!");
- pmap_insert(node_loop_map, (void *)n, (void *)loop);
-}
-/* Uses temporary information to get the loop */
-INLINE ir_loop *
-get_irn_loop (ir_node *n) {
- ir_loop *res = NULL;
- if (!node_loop_map) return NULL;
-
- if (pmap_contains(node_loop_map, (void *)n))
- res = (ir_loop *) pmap_get(node_loop_map, (void *)n);
-
- return res;
-}
-#else
INLINE void
set_irn_loop (ir_node *n, ir_loop* loop) {
n->loop = loop;
get_irn_loop (ir_node *n) {
return n->loop;
}
-#endif
#if 0
son->outer_loop = father;
add_loop_son(father, son);
son->depth = father->depth+1;
+ if (son->depth > max_loop_depth) max_loop_depth = son->depth;
} else { /* The root loop */
son->outer_loop = son;
son->depth = 0;
loop_element ln;
ln.node = n;
assert(loop && loop->kind == k_ir_loop);
- assert(get_kind(n) == k_ir_node);
+ assert(get_kind(n) == k_ir_node || get_kind(n) == k_ir_graph); /* used in callgraph.c */
ARR_APP1 (loop_element, loop->children, ln);
loop->n_nodes++;
}
(get_irn_op(cb) == op_EndReg) ||
(get_irn_op(cb) == op_EndExcept)) {
init_node(cb, NULL);
- init_node(get_nodes_Block(cb), NULL);
+ init_node(get_nodes_block(cb), NULL);
}
}
#endif
init_scc_common (void) {
current_dfn = 1;
loop_node_cnt = 0;
- if (!node_loop_map) node_loop_map = pmap_create();
init_stack();
}
if ((get_irn_op(n) == op_Block) &&
(get_Block_n_cfgpreds(n) == 1) &&
(get_irn_op(skip_Proj(get_Block_cfgpred(n, 0))) == op_Start) &&
- (get_nodes_Block(skip_Proj(get_Block_cfgpred(n, 0))) == n)) {
+ (get_nodes_block(skip_Proj(get_Block_cfgpred(n, 0))) == n)) {
return true;
}
#if 0
if (get_irn_op(n) == op_Phi ||
get_irn_op(n) == op_Block ||
(get_irn_op(n) == op_Filter && interprocedural_view) ||
- (get_irg_pinned(get_irn_irg(n)) == floats &&
- get_op_pinned(get_irn_op(n)) == floats))
+ (get_irg_pinned(get_irn_irg(n)) == op_pin_state_floats &&
+ get_irn_pinned(n) == op_pin_state_floats))
// Here we could test for backedge at -1 which is illegal
return 0;
else
if (res_index == -2) /* no smallest dfn pred found. */
res_index = largest_dfn_pred (m);
- if ((m == n) && (res_index == -2)) {
+ if ((m == n) && (res_index == -2)) { /* dont walk past loop head. */
i = -1;
}
break;
int arity = get_irn_arity(start_block);
for(j = 0; j < arity; j++)
{
- ir_node *begin_projx = get_Block_cfgpred(get_irg_start_block(get_irn_irg(end_projx)), get_Proj_proj(end_projx));
+ ir_node *begin_projx = get_Block_cfgpred(get_irg_start_block(get_irn_irg(end_projx)),
+ get_Proj_proj(end_projx));
DDMN(begin_projx);
if(get_irn_n(start_block, j) == begin_projx)
{
static pmap *projx_link = NULL;
void link_to_reg_end (ir_node *n, void *env) {
- if(get_irn_op(n) == op_Proj && get_irn_mode(n) == mode_X && get_irn_op(get_irn_n(n, 0)) == op_EndReg)
- {
+ if(get_irn_op(n) == op_Proj &&
+ get_irn_mode(n) == mode_X &&
+ get_irn_op(get_irn_n(n, 0)) == op_EndReg) {
/* Reg End Projx -> Find the CallBegin Projx and hash it */
ir_node *end_projx = n;
- ir_node *begin_projx = get_Block_cfgpred(get_irg_start_block(get_irn_irg(end_projx)), get_Proj_proj(end_projx));
+ ir_node *begin_projx = get_Block_cfgpred(get_irg_start_block(get_irn_irg(end_projx)),
+ get_Proj_proj(end_projx));
printf("Linked the following ProjxNodes:\n");
DDMN(begin_projx);
DDMN(end_projx);
#endif
+INLINE static int
+is_outermost_loop(ir_loop *l) {
+ return l == get_loop_outer_loop(l);
+}
/*-----------------------------------------------------------*
Next actions: Open a new loop on the loop tree and
try to find inner loops */
-#define NO_LOOPS_WITHOUT_HEAD 1
#if NO_LOOPS_WITHOUT_HEAD
/* This is an adaption of the algorithm from fiasco / optscc to
* avoid loops without Block or Phi as first node. This should
* severely reduce the number of evaluations of nodes to detect
* a fixpoint in the heap analysis.
* Further it avoids loops without firm nodes that cause errors
- * in the heap analyses. */
+ * in the heap analyses.
+ * But attention: don't do it for the outermost loop: This loop
+ * is not iterated. A first block can be a loop head in case of
+ * an endless recursion. */
ir_loop *l;
int close;
- if (get_loop_n_elements(current_loop) > 0) {
+ if ((get_loop_n_elements(current_loop) > 0) || (is_outermost_loop(current_loop))) {
l = new_loop();
close = 1;
} else {
}
}
+static void my_scc (ir_node *n) {
+ int i;
+ if (irn_visited(n)) return;
+ mark_irn_visited(n);
+
+ /* Initialize the node */
+ set_irn_dfn(n, current_dfn); /* Depth first number for this node */
+ set_irn_uplink(n, current_dfn); /* ... is default uplink. */
+ set_irn_loop(n, NULL);
+ current_dfn ++;
+ push(n);
+
+ /* AS: get_start_index might return -1 for Control Flow Nodes, and thus a negative
+ array index would be passed to is_backedge(). But CFG Nodes dont't have a backedge array,
+ so is_backedge does not access array[-1] but correctly returns false! */
+
+ if (!is_outermost_Start(n)) {
+ int arity = get_irn_arity(n);
+
+ for (i = get_start_index(n); i < arity; i++) {
+ ir_node *m;
+ if (is_backedge(n, i)) continue;
+ m = get_irn_n(n, i); /* get_irn_ip_pred(n, i); */
+ /* if ((!m) || (get_irn_op(m) == op_Unknown)) continue; */
+ my_scc (m);
+ if (irn_is_in_stack(m)) {
+ /* Uplink of m is smaller if n->m is a backedge.
+ Propagate the uplink to mark the loop. */
+ if (get_irn_uplink(m) < get_irn_uplink(n))
+ set_irn_uplink(n, get_irn_uplink(m));
+ }
+ }
+ }
+
+ if (get_irn_dfn(n) == get_irn_uplink(n)) {
+ /* This condition holds for
+ 1) the node with the incoming backedge.
+ That is: We found a loop!
+ 2) Straight line code, because no uplink has been propagated, so the
+ uplink still is the same as the dfn.
+
+ But n might not be a proper loop head for the analysis. Proper loop
+ heads are Block and Phi nodes. find_tail searches the stack for
+ Block's and Phi's and takes those nodes as loop heads for the current
+ loop instead and marks the incoming edge as backedge. */
+
+ ir_node *tail = find_tail(n);
+ if (tail) {
+ /* We have a loop, that is no straight line code,
+ because we found a loop head!
+ Next actions: Open a new loop on the loop tree and
+ try to find inner loops */
+
+#if NO_LOOPS_WITHOUT_HEAD
+ /* This is an adaption of the algorithm from fiasco / optscc to
+ * avoid loops without Block or Phi as first node. This should
+ * severely reduce the number of evaluations of nodes to detect
+ * a fixpoint in the heap analysis.
+ * Further it avoids loops without firm nodes that cause errors
+ * in the heap analyses. */
+
+ ir_loop *l;
+ int close;
+ if ((get_loop_n_elements(current_loop) > 0) || (is_outermost_loop(current_loop))) {
+ l = new_loop();
+ close = 1;
+ } else {
+ l = current_loop;
+ close = 0;
+ }
+#else
+ ir_loop *l = new_loop();
+#endif
+
+ /* Remove the loop from the stack ... */
+ pop_scc_unmark_visit (n);
+
+ /* The current backedge has been marked, that is temporarily eliminated,
+ by find tail. Start the scc algorithm
+ anew on the subgraph thats left (the current loop without the backedge)
+ in order to find more inner loops. */
+ my_scc (tail);
+
+ assert (irn_visited(n));
+#if NO_LOOPS_WITHOUT_HEAD
+ if (close)
+#endif
+ close_loop(l);
+ }
+ else
+ {
+ /* No loop head was found, that is we have straightline code.
+ Pop all nodes from the stack to the current loop. */
+ pop_scc_to_loop(n);
+ }
+ }
+}
+
/* Constructs backedge information for irg. In interprocedural view constructs
backedges for all methods called by irg, too. */
-void construct_backedges(ir_graph *irg) {
+int construct_backedges(ir_graph *irg) {
ir_graph *rem = current_ir_graph;
ir_loop *head_rem;
assert(!interprocedural_view &&
"not implemented, use construct_ip_backedges");
- current_ir_graph = irg;
+ max_loop_depth = 0;
+ current_ir_graph = irg;
outermost_ir_graph = irg;
init_scc(current_ir_graph);
new_loop(); /* sets current_loop */
head_rem = current_loop; /* Just for assertion */
- if (interprocedural_view) {
- set_irg_visited(current_ir_graph, inc_max_irg_visited());
- init_ip_walk ();
- } else {
- inc_irg_visited(current_ir_graph);
- }
+ inc_irg_visited(current_ir_graph);
scc(get_irg_end(current_ir_graph));
- if (interprocedural_view) finish_ip_walk();
-
assert(head_rem == current_loop);
set_irg_loop(current_ir_graph, current_loop);
set_irg_loopinfo_state(current_ir_graph, loopinfo_consistent);
}
*/
current_ir_graph = rem;
+
+ return max_loop_depth;
}
-#if 0
-void construct_ip_backedges (void) {
+int construct_ip_backedges (void) {
ir_graph *rem = current_ir_graph;
int rem_ipv = interprocedural_view;
- int i, j;
+ int i;
+
+ max_loop_depth = 0;
+ assert(get_irp_ip_view_state() == ip_view_valid);
outermost_ir_graph = get_irp_main_irg();
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);
- /* Find real entry points */
+
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;
- /* Compute scc for this graph */
- outermost_ir_graph = current_ir_graph;
- set_irg_visited(outermost_ir_graph, get_max_irg_visited());
+ (get_nodes_block(get_Block_cfgpred(sb, 0)) != sb)) continue;
+
scc(get_irg_end(current_ir_graph));
- for (j = 0; j < get_End_n_keepalives(get_irg_end(outermost_ir_graph)); j++)
- scc(get_End_keepalive(get_irg_end(outermost_ir_graph), j));
+ }
+
+ /* 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)) scc(sb);
+ }
+
+ /* Walk all endless loops 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++) scc(get_End_keepalive(e, j));
+ }
}
set_irg_loop(outermost_ir_graph, current_loop);
current_ir_graph = rem;
interprocedural_view = rem_ipv;
+ return max_loop_depth;
}
-#else
-void construct_ip_backedges (void) {
+
+void my_construct_ip_backedges (void) {
ir_graph *rem = current_ir_graph;
int rem_ipv = interprocedural_view;
int i;
if ((get_Block_n_cfgpreds(sb) > 1) ||
(get_nodes_block(get_Block_cfgpred(sb, 0)) != sb)) continue;
- scc(get_irg_end(current_ir_graph));
+ my_scc(get_irg_end(current_ir_graph));
}
/* Check whether we walked all procedures: there could be procedures
current_ir_graph = rem;
interprocedural_view = rem_ipv;
}
-#endif
static void reset_backedges(ir_node *n) {
if (is_possible_loop_head(n)) {
for (i = 0; i < get_irp_n_irgs(); i++) {
free_loop_information(get_irp_irg(i));
}
- pmap_destroy(node_loop_map);
- node_loop_map = NULL;
interprocedural_view = rem;
}
projects / libfirm / blobdiff