#include <string.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
+
+
+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);
+ir_node *get_projx_link(ir_node *cb_projx);
/**********************************************************************/
/* Node attributes **/
/**********************************************************************/
-/* A map to get from irnodes to loop nodes. */
-static pmap *node_loop_map = NULL;
-
/**********************************************************************/
/* Node attributes needed for the construction. **/
/**********************************************************************/
((scc_info *)n->link)->uplink = uplink;
}
-static INLINE int
+INLINE int
get_irn_uplink (ir_node *n) {
assert(get_irn_link(n));
/* from fast to slow */
((scc_info *)n->link)->dfn = dfn;
}
-static INLINE int
+INLINE int
get_irn_dfn (ir_node *n) {
assert(get_irn_link(n));
/* to slow */
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 */
-static 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
-static INLINE void
+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
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);
+
loop_node_cnt++;
set_irn_dfn(m, loop_node_cnt);
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_nodes in them. Such loops have only another loop as son. (Why
can't they have two loops as sons? Does it never get that far? ) */
-void close_loop (ir_loop *l)
+static void close_loop (ir_loop *l)
{
int last = get_loop_n_elements(l) - 1;
loop_element lelement = get_loop_element(l, last);
/* Allocates a new loop as son of current_loop. Sets current_loop
to the new loop and returns the father. */
-static ir_loop *new_loop (void) {
+ir_loop *new_loop (void) {
ir_loop *father, *son;
father = current_loop;
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;
/* Use EXCLUSIVELY this function to add sons, otherwise the loop->n_sons
is invalid! */
-static INLINE void
+INLINE void
add_loop_son(ir_loop *loop, ir_loop *son) {
loop_element lson;
lson.son = son;
/* Use EXCLUSIVELY this function to add nodes, otherwise the loop->n_nodes
is invalid! */
-static INLINE void
+INLINE 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++;
}
/* 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 (intern_get_irn_op(n) == op_Filter) {
+ 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 (intern_get_irn_op(n) == op_Block) {
+ 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 ((intern_get_irn_op(n) == op_Proj) /*&& (get_Proj_proj(n) == 0)*/) {
+ 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 ((intern_get_irn_op(cb) == op_CallBegin) ||
- (intern_get_irn_op(cb) == op_EndReg) ||
- (intern_get_irn_op(cb) == op_EndExcept)) {
+ 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);
+ 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();
}
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. */
static bool is_outermost_Start(ir_node *n) {
/* Test whether this is the outermost Start node. If so
recursion must end. */
- if ((intern_get_irn_op(n) == op_Block) &&
+ if ((get_irn_op(n) == op_Block) &&
(get_Block_n_cfgpreds(n) == 1) &&
- (intern_get_irn_op(skip_Proj(get_Block_cfgpred(n, 0))) == op_Start) &&
- (get_nodes_Block(skip_Proj(get_Block_cfgpred(n, 0))) == n)) {
+ (get_irn_op(skip_Proj(get_Block_cfgpred(n, 0))) == op_Start) &&
+ (get_nodes_block(skip_Proj(get_Block_cfgpred(n, 0))) == n)) {
return true;
}
#if 0
not possible in interprocedural view as outermost_graph is
not necessarily the only with a dead-end start block.
Besides current_ir_graph is not set properly. */
- if ((intern_get_irn_op(n) == op_Block) &&
+ 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;
}
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)
- // this should be sufficient.
- return -1;
- else
- return 0;
- */
- if (intern_get_irn_op(n) == op_Phi ||
- intern_get_irn_op(n) == op_Block ||
- (intern_get_irn_op(n) == op_Filter && interprocedural_view))
+#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 (get_irn_op(n) == op_Phi ||
+ get_irn_op(n) == op_Block ||
+ (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
return -1;
-}
-#if 0
-/* Returns current_ir_graph and set it to the irg of predecessor index
- of node n. */
-static INLINE ir_graph *
-switch_irg (ir_node *n, int index) {
- ir_graph *old_current = current_ir_graph;
-
- if (interprocedural_view) {
- /* Only Filter and Block nodes can have predecessors in other graphs. */
- if (intern_get_irn_op(n) == op_Filter)
- n = get_nodes_Block(n);
- if (intern_get_irn_op(n) == op_Block) {
- ir_node *cfop = skip_Proj(get_Block_cfgpred(n, index));
- if (is_ip_cfop(cfop)) {
- current_ir_graph = get_irn_irg(cfop);
- set_irg_visited(current_ir_graph, get_max_irg_visited());
- }
- }
- }
-
- return old_current;
-}
-/* Walks up the stack passing n and then finding the node
- where we walked into the irg n is contained in.
- Here we switch the irg. */
-static ir_graph *
-find_irg_on_stack (ir_node *n) {
- ir_node *m;
- ir_graph *old_current = current_ir_graph;
- int i;
-
- if (interprocedural_view) {
- for (i = tos; i >= 0; i--) {
- if (stack[i] == n) break;
- }
- if (i < 0) i = tos;
+#else
- assert (i >= 0);
- for (; i >= 0; i--) {
- m = stack[i];
- /*printf(" Visiting %d ", i); DDMN(m);*/
- if (is_ip_cfop(m)) {
- current_ir_graph = get_irn_irg(m);
- break;
- }
- if (intern_get_irn_op(m) == op_Filter) {
- /* Find the corresponding ip_cfop */
- ir_node *pred = stack[i+1];
- int j;
- for (j = 0; j < get_Filter_n_cg_preds(m); j++)
- if (get_Filter_cg_pred(m, j) == pred) break;
- if (j >= get_Filter_n_cg_preds(m))
- /* It is a filter we didn't pass as the predecessors are marked. */
- continue;
- assert(get_Filter_cg_pred(m, j) == pred);
- switch_irg(m, j);
- break;
- }
- }
- }
+ /* 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) || get_irn_op(n) == op_Start)
+ return -1;
+ else
+ return 0;
- return old_current;
-}
#endif
+}
+
#if 0
static void test(ir_node *pred, ir_node *root, ir_node *this) {
/* Test for legal loop header: Block, Phi, ... */
INLINE static bool is_possible_loop_head(ir_node *n) {
- ir_op *op = intern_get_irn_op(n);
+ ir_op *op = get_irn_op(n);
return ((op == op_Block) ||
- (op == op_Phi) ||
- ((op == op_Filter) && interprocedural_view));
+ (op == op_Phi) ||
+ ((op == op_Filter) && get_interprocedural_view()));
}
/* Returns true if n is a loop header, i.e., it is a Block, Phi
return false;
if (!is_outermost_Start(n)) {
- arity = intern_get_irn_arity(n);
+ arity = get_irn_arity(n);
for (i = get_start_index(n); i < arity; i++) {
- ir_node *pred = intern_get_irn_n(n, i);
+ ir_node *pred = get_irn_n(n, i);
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(n); DDMN(pred); DDMN(root);
+ assert(get_irn_uplink(pred) >= get_irn_uplink(root));
+ }
+ some_in_loop = 1;
}
}
}
return some_outof_loop && some_in_loop;
}
+/* Returns true if n is possible loop head of an endless loop.
+ I.e., it is a Block, Phi or Filter node and has only predecessors
+ within the loop.
+ @arg root: only needed for assertion. */
+static bool
+is_endless_head (ir_node *n, ir_node *root)
+{
+ int i, arity;
+ int some_outof_loop = 0, some_in_loop = 0;
+
+ /* Test for legal loop header: Block, Phi, ... */
+ if (!is_possible_loop_head(n))
+ return false;
+
+ if (!is_outermost_Start(n)) {
+ arity = get_irn_arity(n);
+ for (i = get_start_index(n); i < arity; i++) {
+ ir_node *pred = get_irn_n(n, i);
+ assert(pred);
+ if (is_backedge(n, i)) { continue; }
+ if (!irn_is_in_stack(pred)) {
+ some_outof_loop = 1; //printf(" some out of loop ");
+ } else {
+ 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;
+ }
+ }
+ }
+ return !some_outof_loop && some_in_loop;
+}
+
/* Returns index of the predecessor with the smallest dfn number
greater-equal than limit. */
static int
int i, index = -2, min = -1;
if (!is_outermost_Start(n)) {
- int arity = intern_get_irn_arity(n);
+ int arity = get_irn_arity(n);
for (i = get_start_index(n); i < arity; i++) {
- ir_node *pred = intern_get_irn_n(n, i);
+ ir_node *pred = get_irn_n(n, i);
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);
}
}
}
int i, index = -2, max = -1;
if (!is_outermost_Start(n)) {
- int arity = intern_get_irn_arity(n);
+ int arity = get_irn_arity(n);
for (i = get_start_index(n); i < arity; i++) {
- ir_node *pred = intern_get_irn_n(n, i);
+ 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);
}
}
}
return index;
}
-/* Searches the stack for possible loop heads. Tests these for backedges.
- If it finds a head with an unmarked backedge it marks this edge and
- returns the tail of the loop.
- If it finds no backedge returns NULL.
- ("disable_backedge" in fiasco) */
+/** Searches the stack for possible loop heads. Tests these for backedges.
+ If it finds a head with an unmarked backedge it marks this edge and
+ returns the tail of the loop.
+ If it finds no backedge returns NULL.
+ ("disable_backedge" in fiasco)
+*
+* @param n A node where uplink == dfn.
+**/
static ir_node *
find_tail (ir_node *n) {
/*
if (!icfg && rm_cyclic_phis && remove_cyclic_phis (n)) return NULL;
*/
-
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. */
- (n == m))
+ (n == m))
return NULL;
} else {
- if (m == n) return NULL;
- for (i = tos-2; ; --i) {
+ if (m == n) return NULL; // Is this to catch Phi - self loops?
+ for (i = tos-2; i >= 0; --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);
+
+ 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;
+ }
+
+ }
+
+ 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. */
+ }
+ //assert(0 && "no head found on stack");
+ }
+
+ }
+ 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);
- return is_outermost_Start(n) ? NULL : intern_get_irn_n(m, res_index);
+ return is_outermost_Start(n) ? NULL : get_irn_n(m, res_index);
+}
+
+
+#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];
+
+ 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));
+ DDMN(begin_projx);
+ if(get_irn_n(start_block, j) == begin_projx)
+ {
+ printf("FOUND IT!!!!!!!!!!!!!!!!!!\n");
+ return(j);
+ }
+ }
+ }
+ }
+ return(-1);
}
-/* The core algorithm. *****************************************/
+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
+
+INLINE static 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;
so is_backedge does not access array[-1] but correctly returns false! */
if (!is_outermost_Start(n)) {
- int arity = intern_get_irn_arity(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 = intern_get_irn_n(n, i); /* get_irn_ip_pred(n, i); */
- /* if ((!m) || (intern_get_irn_op(m) == op_Unknown)) 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));
+ /* 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.
+ * 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) || (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. */
+ 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);
+ }
+ }
+}
+
+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 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 */
+#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;
+ 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();
/* 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); */
- scc (tail);
- /* GL @@@ remove experimental stuff current_ir_graph = rem; */
+ /* 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 {
- /* AS: No inner loop was found. Pop all nodes from the stack
- to the current loop. */
+ 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 &&
+ 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);
+
outermost_ir_graph = get_irp_main_irg();
init_ip_scc();
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);
}
}
+
+/*
static void loop_reset_backedges(ir_loop *l) {
int i;
reset_backedges(get_loop_node(l, 0));
loop_reset_backedges(get_loop_son(l, i));
}
}
+*/
+
+static void loop_reset_node(ir_node *n, void *env) {
+ set_irn_loop(n, NULL);
+ reset_backedges(n);
+}
+
/** Removes all loop information.
Resets all backedges */
void free_loop_information(ir_graph *irg) {
- if (get_irg_loop(irg))
- loop_reset_backedges(get_irg_loop(irg));
+ /* We can not use this recursion, as the loop might contain
+ illegal nodes by now. Why else would we throw away the
+ representation?
+ if (get_irg_loop(irg)) loop_reset_backedges(get_irg_loop(irg));
+ */
+ irg_walk_graph(irg, loop_reset_node, NULL, NULL);
set_irg_loop(irg, NULL);
set_irg_loopinfo_state(current_ir_graph, loopinfo_none);
/* We cannot free the loop nodes, they are on the obstack. */
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);
}
projects / libfirm / blobdiff