#include "config.h"
#endif
+#ifdef HAVE_STRING_H
#include <string.h>
+#endif
+
+#include <stdlib.h>
#include "irloop_t.h"
-#include "irnode_t.h"
+
+#include "irprog_t.h"
#include "irgraph_t.h"
+#include "irnode_t.h"
+#include "irgwalk.h"
#include "array.h"
#include "pmap.h"
-#include "irgwalk.h"
-#include "irprog_t.h"
+
#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
+
+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. **/
/**********************************************************************/
static INLINE void
mark_irn_in_stack (ir_node *n) {
- assert(get_irn_link(n));
- /* to slow */
- /* ((scc_info *)get_irn_link(n))->in_stack = true; */
- ((scc_info *)n->link)->in_stack = true;
+ scc_info *scc = get_irn_link(n);
+ assert(scc);
+ scc->in_stack = true;
}
static INLINE void
mark_irn_not_in_stack (ir_node *n) {
- assert(get_irn_link(n));
- /* to slow */
- /* ((scc_info *)get_irn_link(n))->in_stack = false; */
- ((scc_info *)n->link)->in_stack = false;
+ scc_info *scc = get_irn_link(n);
+ assert(scc);
+ scc->in_stack = false;
}
static INLINE bool
irn_is_in_stack (ir_node *n) {
- assert(get_irn_link(n));
- /* to slow */
- /* return ((scc_info *)get_irn_link(n))->in_stack; */
- return ((scc_info *)n->link)->in_stack;
+ scc_info *scc = get_irn_link(n);
+ assert(scc);
+ return scc->in_stack;
}
static INLINE void
set_irn_uplink (ir_node *n, int uplink) {
- assert(get_irn_link(n));
- /* to slow */
- /* ((scc_info *)get_irn_link(n))->uplink = uplink; */
- ((scc_info *)n->link)->uplink = uplink;
+ scc_info *scc = get_irn_link(n);
+ assert(scc);
+ scc->uplink = uplink;
}
-INLINE int
+int
get_irn_uplink (ir_node *n) {
- assert(get_irn_link(n));
- /* from fast to slow */
- /* return ((scc_info *)get_irn_link(n))->uplink; */
- return ((scc_info *)n->link)->uplink;
+ scc_info *scc = get_irn_link(n);
+ assert(scc);
+ return scc->uplink;
}
static INLINE void
set_irn_dfn (ir_node *n, int dfn) {
- assert(get_irn_link(n));
- /* to slow */
- /* ((scc_info *)get_irn_link(n))->dfn = dfn; */
- ((scc_info *)n->link)->dfn = dfn;
+ scc_info *scc = get_irn_link(n);
+ assert(scc);
+ scc->dfn = dfn;
}
-INLINE int
+int
get_irn_dfn (ir_node *n) {
- assert(get_irn_link(n));
- /* to slow */
- /* return ((scc_info *)get_irn_link(n))->dfn; */
- return ((scc_info *)n->link)->dfn;
+ scc_info *scc = get_irn_link(n);
+ assert(scc);
+ return scc->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) {
+void
+set_irn_loop (ir_node *n, ir_loop *loop) {
n->loop = loop;
}
/* Uses temporary information to get the loop */
-INLINE ir_loop *
+ir_loop *
get_irn_loop (ir_node *n) {
return n->loop;
}
-#endif
#if 0
static ir_node **stack = NULL;
static int tos = 0; /* top of stack */
+/**
+ * initializes the stack
+ */
static INLINE void init_stack(void) {
if (stack) {
ARR_RESIZE (ir_node *, stack, 1000);
}
#endif
+/**
+ * push a node onto the stack
+ *
+ * @param n The node to push
+ */
static INLINE void
push (ir_node *n)
{
mark_irn_in_stack(n);
}
+/**
+ * pop a node from the stack
+ *
+ * @return The topmost node
+ */
static INLINE ir_node *
pop (void)
{
return n;
}
-/* The nodes up to n belong to the current loop.
- Removes them from the stack and adds them to the current loop. */
+/**
+ * The nodes up to n belong to the current loop.
+ * Removes them from the stack and adds them to the current loop.
+ */
static INLINE void
pop_scc_to_loop (ir_node *n)
{
ir_node *m;
int i = 0;
- /*for (;;) {*/
- do
- {
+ do {
m = pop();
//printf(" dfn: %d, upl %d upl-new %d ", get_irn_dfn(m), get_irn_uplink(m), loop_node_cnt+1); DDMN(m);
add_loop_node(current_loop, m);
set_irn_loop(m, current_loop);
i++;
+
/* if (m==n) break;*/
- } while(m != n);
+ } while(m != n);
- if(i > 1)
+ /* i might be bigger than 1 for dead (and that's why bad) loops */
+ /* if(i > 1)
printf("Mehr als eine Iteration!!!!!!!!!!!!!!!!!!!!!!!!!!!!11111\n");
+ */
}
/* GL ??? my last son is my grandson??? Removes loops with no
ir_loop *last_son = lelement.son;
if (get_kind(last_son) == k_ir_loop &&
- get_loop_n_elements(last_son) == 1)
- {
- ir_loop *gson;
-
- lelement = get_loop_element(last_son, 0);
- gson = lelement.son;
- if(get_kind(gson) == k_ir_loop)
- {
- loop_element new_last_son;
-
- gson -> outer_loop = l;
- new_last_son.son = gson;
- l -> children[last] = new_last_son;
- }
+ get_loop_n_elements(last_son) == 1) {
+ ir_loop *gson;
+
+ lelement = get_loop_element(last_son, 0);
+ gson = lelement.son;
+
+ if (get_kind(gson) == k_ir_loop) {
+ loop_element new_last_son;
+
+ gson->outer_loop = l;
+ new_last_son.son = gson;
+ l->children[last] = new_last_son;
}
+ }
current_loop = l;
}
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;
/* Returns the pos`th loop_node-child *
* TODO: This method isn`t very efficient ! *
- * Returns NULL if there isnt`t a pos`th loop_node */
+ * Returns NULL if there isn`t a pos`th loop_node */
ir_loop *get_loop_son (ir_loop *loop, int pos) {
int child_nr = 0, loop_nr = -1;
/* Use EXCLUSIVELY this function to add sons, otherwise the loop->n_sons
is invalid! */
-INLINE void
+void
add_loop_son(ir_loop *loop, ir_loop *son) {
loop_element lson;
lson.son = son;
/* Returns the pos`th ir_node-child *
* TODO: This method isn`t very efficient ! *
- * Returns NULL if there isnt`t a pos`th ir_node */
+ * Returns NULL if there isn`t a pos`th ir_node */
ir_node *get_loop_node (ir_loop *loop, int pos) {
int child_nr, node_nr = -1;
/* Use EXCLUSIVELY this function to add nodes, otherwise the loop->n_nodes
is invalid! */
-INLINE void
+void
add_loop_node(ir_loop *loop, ir_node *n) {
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++;
}
Returns the pos`th loop element.
This may be a loop_node or a ir_node. The caller of this function has
to check the *(loop_element.kind) field for "k_ir_node" or "k_ir_loop"
- and then select the apropriate "loop_element.node" or "loop_element.son".
+ and then select the appropriate "loop_element.node" or "loop_element.son".
*/
loop_element get_loop_element (ir_loop *loop, int pos) {
#endif
}
+int (is_ir_loop)(const void *thing) {
+ return _is_ir_loop(thing);
+}
+
/* The outermost loop is remarked in the surrounding graph. */
-void set_irg_loop(ir_graph *irg, ir_loop *loop) {
- assert(irg);
- irg->loop = loop;
+void (set_irg_loop)(ir_graph *irg, ir_loop *loop) {
+ _set_irg_loop(irg, loop);
}
-ir_loop *get_irg_loop(ir_graph *irg) {
- assert(irg);
- return irg->loop;
+
+/* Returns the root loop info (if exists) for an irg. */
+ir_loop *(get_irg_loop)(ir_graph *irg) {
+ return _get_irg_loop(irg);
}
init_node (ir_node *n, void *env) {
set_irn_link (n, new_scc_info());
clear_backedges(n);
-#if 0
- /* Also init nodes not visible in intraproc_view. */
- /* @@@ init_node is called for too many nodes -- this wastes memory!.
- The mem is not lost as its on the obstack. */
- if (get_irn_op(n) == op_Filter) {
- for (i = 0; i < get_Filter_n_cg_preds(n); i++)
- init_node(get_Filter_cg_pred(n, i), NULL);
- }
- if (get_irn_op(n) == op_Block) {
- for (i = 0; i < get_Block_cg_n_cfgpreds(n); i++) {
- init_node(get_Block_cg_cfgpred(n, i), NULL);
- }
- }
- /* The following pattern matches only after a call from above pattern. */
- if ((get_irn_op(n) == op_Proj) /*&& (get_Proj_proj(n) == 0)*/) {
- /* @@@ init_node is called for every proj -- this wastes memory!.
- The mem is not lost as its on the obstack. */
- ir_node *cb = get_Proj_pred(n);
- if ((get_irn_op(cb) == op_CallBegin) ||
- (get_irn_op(cb) == op_EndReg) ||
- (get_irn_op(cb) == op_EndExcept)) {
- init_node(cb, NULL);
- init_node(get_nodes_Block(cb), NULL);
- }
- }
-#endif
}
static INLINE void
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
Besides current_ir_graph is not set properly. */
if ((get_irn_op(n) == op_Block) &&
(n == get_irg_start_block(current_ir_graph))) {
- if ((!interprocedural_view) ||
+ if ((!get_interprocedural_view()) ||
(current_ir_graph == outermost_ir_graph))
return true;
}
test showed the loop tree is deeper. */
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_irn_op(n) == op_Filter && get_interprocedural_view()) ||
+ (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
#endif
/* Test for legal loop header: Block, Phi, ... */
-INLINE static bool is_possible_loop_head(ir_node *n) {
+static INLINE bool is_possible_loop_head(ir_node *n) {
ir_op *op = get_irn_op(n);
return ((op == op_Block) ||
(op == op_Phi) ||
- ((op == op_Filter) && interprocedural_view));
+ ((op == op_Filter) && get_interprocedural_view()));
}
/* Returns true if n is a loop header, i.e., it is a Block, Phi
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 = 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);
}
}
}
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;
- }
- 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);
+
+ if ((m == n) && (res_index == -2)) { /* dont walk past loop head. */
+ i = -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;
- break;
+ are not in this loop. We assume a loop not reachable from Start. */
+ if (m == n) {
+ i = -1;
+ break;
}
}
if (i < 0) {
/* A dead loop not reachable from Start. */
for (i = tos-2; i >= 0; --i) {
- 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. */
- res_index = largest_dfn_pred (m);
- break;
- }
- if (m == n) { break; } /* It's not an unreachable loop, either. */
+ 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. */
+ res_index = largest_dfn_pred (m);
+ break;
+ }
+ if (m == n) { break; } /* It's not an unreachable loop, either. */
}
//assert(0 && "no head found on stack");
}
}
- if (res_index <= -2) return NULL;
+ if (res_index <= -2) {
+ /* It's a completely bad loop: without Phi/Block nodes that can
+ be a head. I.e., the code is "dying". We break the loop by
+ setting Bad nodes. */
+ int arity = get_irn_arity(n);
+ for (i = -1; i < arity; ++i) {
+ set_irn_n(n, i, get_irg_bad(get_irn_irg(n)));
+ }
+ return NULL;
+ }
assert (res_index > -2);
set_backedge (m, res_index);
#if EXPERIMENTAL_LOOP_TREE
/* ----------------------------------------------------------------
- AS: This is experimantal code to build loop trees suitable for
+ AS: This is experimental code to build loop trees suitable for
the heap analysis. Does not work correctly right now... :-(
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++)
+ {
+ 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];
+
+ 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)
- {
- printf("FOUND IT!!!!!!!!!!!!!!!!!!\n");
- return(j);
- }
+ {
+ 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)
- {
+ 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
+static INLINE int
+is_outermost_loop(ir_loop *l) {
+ return l == get_loop_outer_loop(l);
+}
/*-----------------------------------------------------------*
* The core algorithm. *
*-----------------------------------------------------------*/
-
static void scc (ir_node *n) {
int i;
if (irn_visited(n)) return;
if (!is_outermost_Start(n)) {
int arity = get_irn_arity(n);
-#if EXPERIMENTAL_LOOP_TREE
+ 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; */
+ 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));
+ }
+ }
+ }
- /* 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 (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.
- 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;
+ 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 */
- 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 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.
+ * 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. */
- 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));
- }
- }
+ 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
-
+#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 that is left (the current loop without the backedge)
+ in order to find more inner loops. */
+ scc (tail);
+
+ assert (irn_visited(n));
+#if NO_LOOPS_WITHOUT_HEAD
+ if (close)
+#endif
+ close_loop(l);
+ }
+ else
{
- 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; */
- 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));
- }
- }
+ /* 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);
+ }
+ }
+}
+
+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)) {
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
ir_loop *l;
int close;
- if (get_loop_n_elements(current_loop) > 0) {
- l = new_loop();
- close = 1;
+ if ((get_loop_n_elements(current_loop) > 0) || (is_outermost_loop(current_loop))) {
+ 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);
- /* 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)
+ anew on the subgraph that is left (the current loop without the backedge)
in order to find more inner loops. */
-
- scc (tail);
-
- /* GL @@@ remove experimental stuff current_ir_graph = rem; */
+ my_scc (tail);
assert (irn_visited(n));
#if NO_LOOPS_WITHOUT_HEAD
}
else
{
- /* AS: No loop head was found, that is we have straightline code.
- Pop all nodes from the stack to the current loop. */
+ /* 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 &&
+ assert(!get_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 rem_ipv = get_interprocedural_view();
+ int i;
+
+ max_loop_depth = 0;
+ assert(get_irp_ip_view_state() == ip_view_valid);
outermost_ir_graph = get_irp_main_irg();
current_loop = NULL;
new_loop(); /* sets current_loop */
- interprocedural_view = 1;
+ set_interprocedural_view(true);
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);
- /* 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);
assert(get_irg_loop(outermost_ir_graph)->kind == k_ir_loop);
current_ir_graph = rem;
- interprocedural_view = rem_ipv;
+ set_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 rem_ipv = get_interprocedural_view();
int i;
assert(get_irp_ip_view_state() == ip_view_valid);
current_loop = NULL;
new_loop(); /* sets current_loop */
- interprocedural_view = 1;
+ set_interprocedural_view(true);
inc_max_irg_visited();
for (i = 0; i < get_irp_n_irgs(); 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
assert(get_irg_loop(outermost_ir_graph)->kind == k_ir_loop);
current_ir_graph = rem;
- interprocedural_view = rem_ipv;
+ set_interprocedural_view(rem_ipv);
}
-#endif
static void reset_backedges(ir_node *n) {
if (is_possible_loop_head(n)) {
- int rem = interprocedural_view;
- interprocedural_view = 1;
+ int rem = get_interprocedural_view();
+
+ set_interprocedural_view(true);
clear_backedges(n);
- interprocedural_view = 0;
+ set_interprocedural_view(true);
clear_backedges(n);
- interprocedural_view = rem;
+ set_interprocedural_view(rem);
}
}
void free_all_loop_information (void) {
int i;
- int rem = interprocedural_view;
- interprocedural_view = 1; /* To visit all filter nodes */
+ int rem = get_interprocedural_view();
+ set_interprocedural_view(true); /* To visit all filter nodes */
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;
+ set_interprocedural_view(rem);
}
dump_loop(l, "-ha");
}
- if (get_loop_loop_nr(l) == 11819)
- dump_loop(l, "-ha-debug");
-
return found_problem;
}
if (found_problem) exit(0);
}
+
+/* ------------------------------------------------------------------- */
+/* Simple analyses based on the loop information */
+/* ------------------------------------------------------------------- */
+
+int is_loop_variant(ir_loop *l, ir_loop *b) {
+ int i, n_elems;
+
+ if (l == b) return true;
+
+ n_elems = get_loop_n_elements(l);
+ for (i = 0; i < n_elems; ++i) {
+ loop_element e = get_loop_element(l, i);
+ if (is_ir_loop(e.kind))
+ if (is_loop_variant(e.son, b))
+ return true;
+ }
+
+ return false;
+}
+
+/* Test whether a value is loop invariant.
+ *
+ * @param n The node to be tested.
+ * @param block A block node. We pass the block, not the loop as we must
+ * start off with a block loop to find all proper uses.
+ *
+ * Returns true, if the node n is not changed in the loop block
+ * belongs to or in inner loops of this blocks loop. */
+int is_loop_invariant(ir_node *n, ir_node *block) {
+ ir_loop *l = get_irn_loop(block);
+ ir_node *b = (is_Block(n)) ? n : get_nodes_block(n);
+ return !is_loop_variant(l, get_irn_loop(b));
+}
projects / libfirm / blobdiff