static int current_dfn = 1; /* Counter to generate depth first numbering
of visited nodes. */
+void link_to_reg_end (ir_node *n, void *env);
+void set_projx_link(ir_node *cb_projx, ir_node *end_projx);
+ir_node *get_projx_link(ir_node *cb_projx);
+
/**********************************************************************/
/* Node attributes **/
/**********************************************************************/
if(node_nr == pos)
return(loop -> children[child_nr].node);
}
+ DDML(loop);
+ printf("pos: %d\n", pos);
assert(0 && "no child at pos found");
return NULL;
}
init_ip_scc (void) {
init_scc_common();
cg_walk (init_node, NULL, NULL);
+
+#if EXPERIMENTAL_LOOP_TREE
+ cg_walk (link_to_reg_end, NULL, NULL);
+#endif
}
/* Condition for breaking the recursion. */
return false;
}
-/* Don't walk from nodes to blocks except for Control flow operations. */
+/* When to walk from nodes to blocks. Only for Control flow operations? */
static INLINE int
get_start_index(ir_node *n) {
- if (is_cfop(n) || is_fragile_op(n) || intern_get_irn_op(n) == op_Start)
- return -1;
- else
+#undef BLOCK_BEFORE_NODE
+#define BLOCK_BEFORE_NODE 1
+
+#if BLOCK_BEFORE_NODE
+
+ /* This version assures, that all nodes are ordered absolutely. This allows
+ to undef all nodes in the heap analysis if the block is false, which means
+ not reachable.
+ I.e., with this code, the order on the loop tree is correct. But a (single)
+ test showed the loop tree is deeper. */
+ if (intern_get_irn_op(n) == op_Phi ||
+ intern_get_irn_op(n) == op_Block ||
+ (intern_get_irn_op(n) == op_Filter && interprocedural_view) ||
+ (get_irg_pinned(get_irn_irg(n)) == floats &&
+ get_op_pinned(get_irn_op(n)) == floats))
+ // Here we could test for backedge at -1 which is illegal
return 0;
+ else
+ return -1;
+
+#else
+
+ /* This version causes deeper loop trees (at least we verified this
+ for Polymor).
+ But it guarantees that Blocks are analysed before nodes contained in the
+ block. If so, we can set the value to undef if the block is not \
+ executed. */
+ if (is_cfop(n) || is_fragile_op(n) || intern_get_irn_op(n) == op_Start)
+ return -1;
+ else
+ return 0;
+
+#endif
}
+
+
#if 0
/* Returns current_ir_graph and set it to the irg of predecessor index
of node n. */
INLINE static bool is_possible_loop_head(ir_node *n) {
ir_op *op = intern_get_irn_op(n);
return ((op == op_Block) ||
- (op == op_Phi) ||
- ((op == op_Filter) && interprocedural_view));
+ (op == op_Phi) ||
+ ((op == op_Filter) && interprocedural_view));
}
/* Returns true if n is a loop header, i.e., it is a Block, Phi
assert(pred);
if (is_backedge(n, i)) continue;
if (!irn_is_in_stack(pred)) {
- some_outof_loop = 1;
+ some_outof_loop = 1;
} else {
- assert(get_irn_uplink(pred) >= get_irn_uplink(root));
- some_in_loop = 1;
+ if(get_irn_uplink(pred) < get_irn_uplink(root))
+ {
+ DDMN(pred); DDMN(root);
+ }
+ assert(get_irn_uplink(pred) >= get_irn_uplink(root));
+ some_in_loop = 1;
}
}
}
assert(pred);
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);
+ index = i;
+ min = get_irn_dfn(pred);
}
}
}
ir_node *pred = intern_get_irn_n(n, i);
if (is_backedge (n, i) || !irn_is_in_stack(pred)) continue;
if (get_irn_dfn(pred) > max) {
- index = i;
- max = get_irn_dfn(pred);
+ index = i;
+ max = get_irn_dfn(pred);
}
}
}
if (is_head (m, n)) {
res_index = smallest_dfn_pred(m, 0);
if ((res_index == -2) && /* no smallest dfn pred found. */
- (n == m))
+ (n == m))
return NULL;
} else {
if (m == n) return NULL;
for (i = tos-2; ; --i) {
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);
- break;
+ 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);
+ break;
}
}
}
}
-/* The core algorithm. *****************************************/
+#if EXPERIMENTAL_LOOP_TREE
+
+/* ----------------------------------------------------------------
+ AS: This is experimantal code to build loop trees suitable for
+ the heap analysis. Does not work correctly right now... :-(
+
+
+ Search in stack for the corresponding first Call-End-ProjX that
+ corresponds to one of the control flow predecessors of the given
+ block, that is the possible callers.
+ returns: the control predecessor to chose\
+ or -1 if no corresponding Call-End-Node could be found
+ on the stack.
+ - -------------------------------------------------------------- */
+
+int search_endproj_in_stack(ir_node *start_block)
+{
+ int i, j;
+ assert(is_Block(start_block));
+ for(i = tos - 1; i >= 0; --i)
+ {
+ DDMN(stack[i]);
+ if(get_irn_op(stack[i]) == op_Proj && get_irn_mode(stack[i]) == mode_X &&
+ get_irn_op(get_irn_n(stack[i], 0)) == op_EndReg)
+ {
+ printf("FOUND PROJ!!!!!!!!!!!!!!!!!!!!!!!!!!\n");
+ ir_node *end_projx = stack[i];
+
+ for(j = 0; j < get_irn_arity(start_block); j++)
+ {
+ 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)
+ {
+ printf("FOUND IT!!!!!!!!!!!!!!!!!!\n");
+ return(j);
+ }
+ }
+ }
+ }
+ return(-1);
+}
+
+
+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)
+ {
+ /* 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));
+ printf("Linked the following ProjxNodes:\n");
+ DDMN(begin_projx);
+ DDMN(end_projx);
+ set_projx_link(begin_projx, end_projx);
+ }
+}
+
+void set_projx_link(ir_node *cb_projx, ir_node *end_projx)
+{
+ if(projx_link == NULL)
+ projx_link = pmap_create();
+ pmap_insert(projx_link, (void *)cb_projx, (void *)end_projx);
+}
+
+ir_node *get_projx_link(ir_node *cb_projx)
+{
+ return((ir_node *) pmap_get(projx_link, (void *)cb_projx));
+}
+
+#endif
+
+
+
+/*************************************************************
+ * The core algorithm. *
+ *************************************************************/
+
static void scc (ir_node *n) {
- int i;
+ int i, *visited;
if (irn_visited(n)) return;
mark_irn_visited(n);
if (!is_outermost_Start(n)) {
int arity = intern_get_irn_arity(n);
- for (i = get_start_index(n); i < arity; i++) {
- ir_node *m;
- if (is_backedge(n, i)) continue;
- m = intern_get_irn_n(n, i); /* get_irn_ip_pred(n, i); */
- /* if ((!m) || (intern_get_irn_op(m) == op_Unknown)) continue; */
- 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 EXPERIMENTAL_LOOP_TREE
+
+ /* This is meant to be used with the experimenatl code above.
+ If the above code is not used any more, this can be deleted, too.... */
+
+ if(interprocedural_view &&
+ is_Block(n) &&
+ get_irn_op(get_irn_n(n, 0)) == op_Proj &&
+ get_irn_op(get_irn_n(get_irn_n(n, 0), 0)) == op_CallBegin)
+ {
+ /* We are at the start node of a function:
+ Walk to the callers in the correct order! */
+ DDMN(n);
+ DDMN(get_irn_n(get_irn_n(n, 0), 0));
+ for(i = 0; i < arity; i++)
+ {
+ int pred_nr;
+ ir_node *m;
+
+ pred_nr = search_endproj_in_stack(n);
+ assert(pred_nr >= 0);
+ if(is_backedge(n, pred_nr))
+ continue;
+ m = get_irn_n(n, pred_nr);
+ 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));
+ }
+ }
+ }
+ else
+
+#endif
+
+ {
+ for (i = get_start_index(n); i < arity; i++) {
+ ir_node *m;
+ if (is_backedge(n, i)) continue;
+ /* printf("i: %d\n", i); */
+ m = intern_get_irn_n(n, i); /* get_irn_ip_pred(n, i); */
+ /* if ((!m) || (intern_get_irn_op(m) == op_Unknown)) continue; */
+ 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 the node with the incoming backedge.
- AS: That is: For the loop head. */
+ /* 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 found a new inner loop! */
+ /* 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 */
+
+
+#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 analyses.
+ * a fixpoint in the heap analysis.
* Further it avoids loops without firm nodes that cause errors
* in the heap analyses. */
-#define NO_LOOPS_WITHOUT_HEAD 1
-#if NO_LOOPS_WITHOUT_HEAD
+
ir_loop *l;
int close;
if (get_loop_n_elements(current_loop) > 0) {
- l = new_loop();
- close = 1;
+ l = new_loop();
+ close = 1;
} else {
- l = current_loop;
- close = 0;
+ l = current_loop;
+ close = 0;
}
+
#else
+
ir_loop *l = new_loop();
+
#endif
/* Remove the loop from the stack ... */
pop_scc_unmark_visit (n);
- /* and recompute it in a better order; and so that it goes into
- the new loop. */
+
/* GL @@@ remove experimental stuff rem = find_irg_on_stack(tail); */
+ /* 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. */
+
scc (tail);
+
/* GL @@@ remove experimental stuff current_ir_graph = rem; */
assert (irn_visited(n));
#if NO_LOOPS_WITHOUT_HEAD
if (close)
#endif
- close_loop(l);
- } else {
- /* AS: No inner loop was found. Pop all nodes from the stack
- to the current loop. */
+ close_loop(l);
+ }
+ else
+ {
+ /* AS: 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);
}
}
projects / libfirm / blobdiff