-/* Copyright (C) 2002 by Universitaet Karlsruhe
-** All rights reserved.
-**
-** Authors: Goetz Lindenmaier
-**
-** irscc.c Computing the strongly connected regions and building
-** backedge/loop datastructures.
-**
-*/
-
-/* $Id$ */
+/*
+ * Project: libFIRM
+ * File name: ir/ana/irscc.c
+ * Purpose: Compute the strongly connected regions and build
+ * backedge/loop datastructures.
+ * A variation on the Tarjan algorithm. See also [Trapp:99],
+ * Chapter 5.2.1.2.
+ * Author: Goetz Lindenmaier
+ * Modified by:
+ * Created: 7.2002
+ * CVS-ID: $Id$
+ * Copyright: (c) 2002-2003 Universität Karlsruhe
+ * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
#include <string.h>
#include "irloop_t.h"
-#include "irnode.h"
+#include "irnode_t.h"
#include "irgraph_t.h"
#include "array.h"
-#include "xprintf.h"
+#include "pmap.h"
#include "irgwalk.h"
-#include "irprog.h"
+#include "irprog_t.h"
+#include "irdump.h"
ir_graph *outermost_ir_graph; /* The outermost graph the scc is computed
- for */
+ 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. */
+
+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. **/
bool in_stack; /* Marks whether node is on the stack. */
int dfn; /* Depth first search number. */
int uplink; /* dfn number of ancestor. */
- ir_loop *loop; /* Refers to the containing loop. */
+ /* ir_loop *loop; *//* Refers to the containing loop. */
/*
struct section *section;
xset def;
*/
} scc_info;
-static INLINE scc_info* new_scc_info() {
+static INLINE scc_info* new_scc_info(void) {
scc_info *info = obstack_alloc (outermost_ir_graph->obst, sizeof (scc_info));
memset (info, 0, sizeof (scc_info));
return info;
static INLINE void
mark_irn_in_stack (ir_node *n) {
assert(get_irn_link(n));
- ((scc_info *)get_irn_link(n))->in_stack = true;
+ /* to slow */
+ /* ((scc_info *)get_irn_link(n))->in_stack = true; */
+ ((scc_info *)n->link)->in_stack = true;
}
static INLINE void
mark_irn_not_in_stack (ir_node *n) {
assert(get_irn_link(n));
- ((scc_info *)get_irn_link(n))->in_stack = false;
+ /* to slow */
+ /* ((scc_info *)get_irn_link(n))->in_stack = false; */
+ ((scc_info *)n->link)->in_stack = false;
}
static INLINE bool
irn_is_in_stack (ir_node *n) {
assert(get_irn_link(n));
- return ((scc_info *)get_irn_link(n))->in_stack;
+ /* to slow */
+ /* return ((scc_info *)get_irn_link(n))->in_stack; */
+ return ((scc_info *)n->link)->in_stack;
}
static INLINE void
set_irn_uplink (ir_node *n, int uplink) {
assert(get_irn_link(n));
- ((scc_info *)get_irn_link(n))->uplink = uplink;
+ /* to slow */
+ /* ((scc_info *)get_irn_link(n))->uplink = uplink; */
+ ((scc_info *)n->link)->uplink = uplink;
}
static INLINE int
get_irn_uplink (ir_node *n) {
assert(get_irn_link(n));
- return ((scc_info *)get_irn_link(n))->uplink;
+ /* from fast to slow */
+ /* return ((scc_info *)get_irn_link(n))->uplink; */
+ return ((scc_info *)n->link)->uplink;
}
static INLINE void
set_irn_dfn (ir_node *n, int dfn) {
- if (! get_irn_link(n)) { DDMN(n); DDME(get_irg_ent(current_ir_graph));}
assert(get_irn_link(n));
- ((scc_info *)get_irn_link(n))->dfn = dfn;
+ /* to slow */
+ /* ((scc_info *)get_irn_link(n))->dfn = dfn; */
+ ((scc_info *)n->link)->dfn = dfn;
}
static INLINE int
get_irn_dfn (ir_node *n) {
assert(get_irn_link(n));
- return ((scc_info *)get_irn_link(n))->dfn;
+ /* to slow */
+ /* return ((scc_info *)get_irn_link(n))->dfn; */
+ 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_tmp (ir_node *n, ir_loop* loop) {
- assert(get_irn_link(n));
- ((scc_info *)get_irn_link(n))->loop = 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 */
-static INLINE ir_loop *
-get_irn_loop_tmp (ir_node *n) {
- assert(get_irn_link(n));
- return ((scc_info *)get_irn_link(n))->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;
}
-ir_loop *find_nodes_loop (ir_node *n, ir_loop *l) {
+/* Uses temporary information to get the loop */
+INLINE ir_loop *
+get_irn_loop (ir_node *n) {
+ return n->loop;
+}
+#endif
+
+
+#if 0
+static ir_loop *find_nodes_loop (ir_node *n, ir_loop *l) {
int i;
ir_loop *res = NULL;
l = find_nodes_loop(n, l);
return l;
}
+#endif
/**********************************************************************/
/* A stack. **/
static ir_node **stack = NULL;
static int tos = 0; /* top of stack */
-static INLINE void init_stack() {
+static INLINE void init_stack(void) {
if (stack) {
ARR_RESIZE (ir_node *, stack, 1000);
} else {
tos = 0;
}
-static INLINE void free_stack() {
+#if 0
+static INLINE void free_stack(void) {
DEL_ARR_F(stack);
stack = NULL;
tos = 0;
}
+#endif
static INLINE void
push (ir_node *n)
{
- //DDMN(n);
+ /*DDMN(n);*/
if (tos == ARR_LEN (stack)) {
int nlen = ARR_LEN (stack) * 2;
pop_scc_to_loop (ir_node *n)
{
ir_node *m;
+ int i = 0;
- for (;;) {
+ /*for (;;) {*/
+ do
+ {
m = pop();
- set_irn_dfn(m, loop_node_cnt);
loop_node_cnt++;
+ set_irn_dfn(m, loop_node_cnt);
add_loop_node(current_loop, m);
- set_irn_loop_tmp(m, current_loop);
- if (m==n) break;
- }
+ set_irn_loop(m, current_loop);
+ i++;
+ /* if (m==n) break;*/
+ } while(m != n);
+
+ 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? ) */
+static void close_loop (ir_loop *l)
+{
+ int last = get_loop_n_elements(l) - 1;
+ loop_element lelement = get_loop_element(l, last);
+ 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;
+ }
+ }
+
+ current_loop = l;
}
/* Removes and unmarks all nodes up to n from the stack.
son = (ir_loop *) obstack_alloc (outermost_ir_graph->obst, sizeof (ir_loop));
memset (son, 0, sizeof (ir_loop));
son->kind = k_ir_loop;
- son->sons = NEW_ARR_F (ir_loop *, 0);
- son->nodes = NEW_ARR_F (ir_node *, 0);
+ son->children = NEW_ARR_F (loop_element, 0);
+ son->n_nodes = 0;
+ son->n_sons=0;
if (father) {
son->outer_loop = father;
add_loop_son(father, son);
son->depth = 0;
}
+#ifdef DEBUG_libfirm
+ son->loop_nr = get_irp_new_node_nr();
+ son->link = NULL;
+#endif
+
current_loop = son;
return father;
}
+#if 0
/* Finishes the datastructures, copies the arrays to the obstack
- of current_ir_graph. */
-void mature_loop (ir_loop *loop) {
+ of current_ir_graph.
+ A. Schoesser: Caution: loop -> sons is gone. */
+static void mature_loop (ir_loop *loop) {
ir_loop **new_sons;
- ir_node **new_nods;
new_sons = NEW_ARR_D (ir_loop *, current_ir_graph->obst, ARR_LEN(loop->sons));
memcpy (new_sons, loop->sons, sizeof (ir_loop *) * ARR_LEN(loop->sons));
DEL_ARR_F(loop->sons);
loop->sons = new_sons;
}
+#endif
/* Returns outer loop, itself if outermost. */
ir_loop *get_loop_outer_loop (ir_loop *loop) {
/* Returns the number of inner loops */
int get_loop_n_sons (ir_loop *loop) {
assert(loop && loop->kind == k_ir_loop);
- return ARR_LEN(loop->sons);
+ return(loop -> n_sons);
}
+
+/* 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 */
ir_loop *get_loop_son (ir_loop *loop, int pos) {
+ int child_nr = 0, loop_nr = -1;
+
assert(loop && loop->kind == k_ir_loop);
- return loop->sons[pos];
+ while(child_nr < ARR_LEN(loop->children))
+ {
+ if(*(loop -> children[child_nr].kind) == k_ir_loop)
+ loop_nr++;
+ if(loop_nr == pos)
+ return(loop -> children[child_nr].son);
+ child_nr++;
+ }
+ return NULL;
}
-static INLINE void
+
+/* Use EXCLUSIVELY this function to add sons, otherwise the loop->n_sons
+ is invalid! */
+
+INLINE void
add_loop_son(ir_loop *loop, ir_loop *son) {
+ loop_element lson;
+ lson.son = son;
assert(loop && loop->kind == k_ir_loop);
- ARR_APP1 (ir_loop *, loop->sons, son);
+ assert(get_kind(son) == k_ir_loop);
+ ARR_APP1 (loop_element, loop->children, lson);
+ loop -> n_sons++;
}
/* Returns the number of nodes in the loop */
int get_loop_n_nodes (ir_loop *loop) {
assert(loop); assert(loop->kind == k_ir_loop);
- return ARR_LEN(loop->nodes);
+ return loop -> n_nodes;
+/* return ARR_LEN(loop->nodes); */
}
+
+/* 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 */
ir_node *get_loop_node (ir_loop *loop, int pos) {
+ int child_nr, node_nr = -1;
+
assert(loop && loop->kind == k_ir_loop);
- return loop->nodes[pos];
+ assert(pos < get_loop_n_nodes(loop));
+
+ for (child_nr = 0; child_nr < ARR_LEN(loop->children); child_nr++) {
+ if(*(loop -> children[child_nr].kind) == k_ir_node)
+ node_nr++;
+ 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;
}
-static INLINE void
+
+/* Use EXCLUSIVELY this function to add nodes, otherwise the loop->n_nodes
+ is invalid! */
+
+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);
+ ARR_APP1 (loop_element, loop->children, ln);
+ loop->n_nodes++;
+}
+
+/** Returns the number of elements contained in loop. */
+int get_loop_n_elements (ir_loop *loop) {
+ assert(loop && loop->kind == k_ir_loop);
+ return(ARR_LEN(loop->children));
+}
+
+/*
+ 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".
+*/
+
+loop_element get_loop_element (ir_loop *loop, int pos) {
+ assert(loop && loop->kind == k_ir_loop && pos < ARR_LEN(loop->children));
+
+ return(loop -> children[pos]);
+}
+
+int get_loop_element_pos(ir_loop *loop, void *le) {
+ int i;
assert(loop && loop->kind == k_ir_loop);
- ARR_APP1 (ir_node *, loop->nodes, n);
+
+ for (i = 0; i < get_loop_n_elements(loop); i++)
+ if (get_loop_element(loop, i).node == le) return i;
+ return -1;
+}
+
+int get_loop_loop_nr(ir_loop *loop) {
+ assert(loop && loop->kind == k_ir_loop);
+#ifdef DEBUG_libfirm
+ return loop->loop_nr;
+#else
+ return (int)loop;
+#endif
+}
+
+
+/** A field to connect additional information to a loop. Only valid
+ if libfirm_debug is set. */
+void set_loop_link (ir_loop *loop, void *link) {
+ assert(loop && loop->kind == k_ir_loop);
+#ifdef DEBUG_libfirm
+ loop->link = link;
+#endif
+}
+void *get_loop_link (const ir_loop *loop) {
+ assert(loop && loop->kind == k_ir_loop);
+#ifdef DEBUG_libfirm
+ return loop->link;
+#else
+ return NULL;
+#endif
}
/* The outermost loop is remarked in the surrounding graph. */
return irg->loop;
}
+
/**********************************************************************/
/* Constructing and destructing the loop/backedge information. **/
/**********************************************************************/
static INLINE void
init_node (ir_node *n, void *env) {
- int i;
set_irn_link (n, new_scc_info());
clear_backedges(n);
#if 0
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)) {
+ (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 (ir_graph *irg) {
+init_scc_common (void) {
current_dfn = 1;
loop_node_cnt = 0;
+ if (!node_loop_map) node_loop_map = pmap_create();
init_stack();
+}
+
+static INLINE void
+init_scc (ir_graph *irg) {
+ init_scc_common();
irg_walk_graph (irg, init_node, NULL, NULL);
/*
irg_walk (irg, link_to_reg_end, NULL, NULL);
}
static INLINE void
-init_ip_scc () {
- current_dfn = 1;
- loop_node_cnt = 0;
- init_stack();
+init_ip_scc (void) {
+ init_scc_common();
cg_walk (init_node, NULL, NULL);
-}
-#if 0
-Works, but is inefficient.
-static INLINE void
-init_ip_scc () {
- int i;
- interprocedural_view = 1;
- current_dfn = 1;
- loop_node_cnt = 0;
- init_stack();
- for (i = 0; i < get_irp_n_irgs(); i++) {
- current_ir_graph = get_irp_irg(i);
- irg_walk_graph (current_ir_graph, init_node, NULL, NULL);
- /* @@@ decrease max_visited to avoide double walks */
- }
-}
+
+#if EXPERIMENTAL_LOOP_TREE
+ cg_walk (link_to_reg_end, NULL, NULL);
#endif
+}
/* Condition for breaking the recursion. */
-bool is_outermost_Start(ir_node *n) {
+static bool is_outermost_Start(ir_node *n) {
/* Test whether this is the outermost Start node. If so
recursion must end. */
if ((get_irn_op(n) == op_Block) &&
if ((get_irn_op(n) == op_Block) &&
(n == get_irg_start_block(current_ir_graph))) {
if ((!interprocedural_view) ||
- (current_ir_graph == outermost_ir_graph))
+ (current_ir_graph == outermost_ir_graph))
return true;
}
#endif
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) || 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 (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))
+ // 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) || 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. */
static INLINE ir_graph *
if (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());
+ current_ir_graph = get_irn_irg(cfop);
+ set_irg_visited(current_ir_graph, get_max_irg_visited());
}
}
}
}
if (i < 0) i = tos;
- //printf(" Here\n");
-
assert (i >= 0);
for (; i >= 0; i--) {
m = stack[i];
- //printf(" Visiting %d ", i); DDMN(m);
+ /*printf(" Visiting %d ", i); DDMN(m);*/
if (is_ip_cfop(m)) {
- current_ir_graph = get_irn_irg(m);
- break;
+ current_ir_graph = get_irn_irg(m);
+ break;
}
if (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;
+ /* 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;
}
}
}
return old_current;
}
+#endif
+#if 0
static void test(ir_node *pred, ir_node *root, ir_node *this) {
int i;
if (get_irn_uplink(pred) >= get_irn_uplink(root)) return;
printf(" uplink: %d, pos: %d ", get_irn_uplink(n), i); DDMN(n);
}
}
+#endif
+
+/* Test for legal loop header: Block, Phi, ... */
+INLINE static 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));
+}
/* Returns true if n is a loop header, i.e., it is a Block, Phi
or Filter node and has predecessors within the loop and out
- of the loop. */
+ of the loop.
+ @arg root: only needed for assertion. */
static bool
is_head (ir_node *n, ir_node *root)
{
- int i;
- int some_outof_loop = 0, some_in_loop = 0;
+ int i, arity;
+ int some_outof_loop = 0, some_in_loop = 0;
- /* Test for legal loop header */
- if (!((get_irn_op(n) == op_Block) ||
- (get_irn_op(n) == op_Phi) ||
- ((get_irn_op(n) == op_Filter) && interprocedural_view)))
+ /* Test for legal loop header: Block, Phi, ... */
+ if (!is_possible_loop_head(n))
return false;
if (!is_outermost_Start(n)) {
- for (i = get_start_index(n); i < get_irn_arity(n); i++) {
+ 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;
} 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;
}
int i, index = -2, min = -1;
if (!is_outermost_Start(n)) {
- for (i = get_start_index(n); i < get_irn_arity(n); i++) {
+ int 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) || !irn_is_in_stack(pred)) continue;
- if (get_irn_dfn(pred) >= limit
- && (min == -1 || get_irn_dfn(pred) < min)) {
+ if (get_irn_dfn(pred) >= limit && (min == -1 || get_irn_dfn(pred) < min)) {
index = i;
min = get_irn_dfn(pred);
}
int i, index = -2, max = -1;
if (!is_outermost_Start(n)) {
- for (i = get_start_index(n); i < get_irn_arity(n); i++) {
+ int arity = get_irn_arity(n);
+ for (i = get_start_index(n); i < arity; 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) {
/* 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. */
+ If it finds no backedge returns NULL.
+ ("disable_backedge" in fiasco) */
+
static ir_node *
find_tail (ir_node *n) {
ir_node *m;
if (!icfg && rm_cyclic_phis && remove_cyclic_phis (n)) return NULL;
*/
- m = stack[tos-1];
+ 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;
}
-/* The core algorithm. *****************************************/
+#if EXPERIMENTAL_LOOP_TREE
-void scc (ir_node *n) {
- int i;
- ir_graph *rem;
+/* ----------------------------------------------------------------
+ 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;
if (irn_visited(n)) return;
mark_irn_visited(n);
- //printf("mark: %d ", get_irn_visited(n)); DDMN(n);
- //DDME(get_irg_ent(current_ir_graph));
/* 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_tmp(n, NULL);
+ set_irn_loop(n, NULL);
current_dfn ++;
-
- /* What's this good for?
- n->ana.scc.section = NULL;
- */
-
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)) {
- for (i = get_start_index(n); i < get_irn_arity(n); i++) {
- ir_node *m;
- if (is_backedge(n, i)) continue;
+ int arity = get_irn_arity(n);
+
+#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
- m = get_irn_n(n, i); //get_irn_ip_pred(n, i);
- if ((!m) || (get_irn_op(m) == op_Unknown)) continue;
- scc (m);
- //return_recur(n, i);
+#endif
- 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));
+ {
+ for (i = get_start_index(n); i < arity; i++) {
+ ir_node *m;
+ if (is_backedge(n, i)) continue;
+ /* printf("i: %d\n", i); */
+ 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));
+ }
+ }
}
- }
}
+
if (get_irn_dfn(n) == get_irn_uplink(n)) {
- /* This condition holds for the node with the incoming backedge. */
+ /* 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 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 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) {
+ 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);
- /* and recompute it in a better order; and so that it goes into
- the new loop. */
- rem = find_irg_on_stack(tail);
+
+ /* 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);
- current_ir_graph = rem;
- assert (irn_visited(n));
+ /* GL @@@ remove experimental stuff current_ir_graph = rem; */
- current_loop = l;
- } else {
+ assert (irn_visited(n));
+#if NO_LOOPS_WITHOUT_HEAD
+ if (close)
+#endif
+ 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);
}
}
void construct_backedges(ir_graph *irg) {
ir_graph *rem = current_ir_graph;
ir_loop *head_rem;
- int i;
assert(!interprocedural_view &&
- "not implemented, use construct_ip_backedges");
+ "not implemented, use construct_ip_backedges");
current_ir_graph = irg;
outermost_ir_graph = irg;
- init_scc(irg);
+ init_scc(current_ir_graph);
current_loop = NULL;
new_loop(); /* sets current_loop */
head_rem = current_loop; /* Just for assertion */
if (interprocedural_view) {
- set_irg_visited(irg, inc_max_irg_visited());
+ set_irg_visited(current_ir_graph, inc_max_irg_visited());
init_ip_walk ();
} else {
- inc_irg_visited(irg);
+ inc_irg_visited(current_ir_graph);
}
- scc(get_irg_end(irg));
- for (i = 0; i < get_End_n_keepalives(get_irg_end(irg)); i++)
- scc(get_End_keepalive(get_irg_end(irg), i));
+ scc(get_irg_end(current_ir_graph));
if (interprocedural_view) finish_ip_walk();
assert(head_rem == current_loop);
- set_irg_loop(irg, current_loop);
- assert(get_irg_loop(irg)->kind == k_ir_loop);
+ set_irg_loop(current_ir_graph, current_loop);
+ set_irg_loopinfo_state(current_ir_graph, loopinfo_consistent);
+ assert(get_irg_loop(current_ir_graph)->kind == k_ir_loop);
/*
irg->loops = current_loop;
if (icfg == 1) {
}
-
-void construct_ip_backedges () {
+#if 0
+void construct_ip_backedges (void) {
ir_graph *rem = current_ir_graph;
int rem_ipv = interprocedural_view;
int i, j;
for (i = 0; i < get_irp_n_irgs(); i++) {
ir_node *sb;
current_ir_graph = get_irp_irg(i);
- //DDME(get_irg_ent(current_ir_graph));
/* 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;
- // printf("running scc for "); DDME(get_irg_ent(current_ir_graph));
+ (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());
}
set_irg_loop(outermost_ir_graph, current_loop);
+ set_irg_loopinfo_state(current_ir_graph, loopinfo_ip_consistent);
+ assert(get_irg_loop(outermost_ir_graph)->kind == k_ir_loop);
+
+ current_ir_graph = rem;
+ interprocedural_view = rem_ipv;
+}
+#else
+void construct_ip_backedges (void) {
+ ir_graph *rem = current_ir_graph;
+ int rem_ipv = 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;
+
+ 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;
+
+ scc(get_irg_end(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)) 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);
+ set_irg_loopinfo_state(current_ir_graph, loopinfo_ip_consistent);
assert(get_irg_loop(outermost_ir_graph)->kind == k_ir_loop);
current_ir_graph = rem;
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;
+ clear_backedges(n);
+ interprocedural_view = 0;
+ clear_backedges(n);
+ interprocedural_view = rem;
+ }
+}
+
+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 loop information.
+ Resets all backedges */
+void free_loop_information(ir_graph *irg) {
+ if (get_irg_loop(irg))
+ loop_reset_backedges(get_irg_loop(irg));
+ 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 */
+ 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;
+}
+
+
+
+
+
+/* Debug stuff *************************************************/
+
+static int test_loop_node(ir_loop *l) {
+ int i, has_node = 0, found_problem = 0;
+ loop_element le;
+
+ assert(l && l->kind == k_ir_loop);
+
+ if (get_loop_n_elements(l) == 0) {
+ printf(" Loop completely empty! "); DDML(l);
+ found_problem = 1;
+ dump_loop(l, "-ha");
+ }
+
+ le = get_loop_element(l, 0);
+ if (*(le.kind) != k_ir_node) {
+ assert(le.kind && *(le.kind) == k_ir_loop);
+ printf(" First loop element is not a node! "); DDML(l);
+ printf(" "); DDML(le.son);
+
+ found_problem = 1;
+ dump_loop(l, "-ha");
+ }
+
+ if ((*(le.kind) == k_ir_node) && !is_possible_loop_head(le.node)) {
+ printf(" Wrong node as head! "); DDML(l);
+ printf(" "); DDMN(le.node);
+ found_problem = 1;
+ dump_loop(l, "-ha");
+ }
+
+ if ((get_loop_depth(l) != 0) &&
+ (*(le.kind) == k_ir_node) && !has_backedges(le.node)) {
+ printf(" Loop head has no backedges! "); DDML(l);
+ printf(" "); DDMN(le.node);
+ found_problem = 1;
+ dump_loop(l, "-ha");
+ }
+
+ /* Recur */
+ has_node = 0;
+ for (i = 0; i < get_loop_n_elements(l); ++i) {
+ le = get_loop_element(l, i);
+ if (*(le.kind) == k_ir_node)
+ has_node++;
+ else
+ if (test_loop_node(le.son)) found_problem = 1;
+ }
+
+ if (has_node == 0) {
+ printf(" Loop has no firm node! "); DDML(l);
+ found_problem = 1;
+ dump_loop(l, "-ha");
+ }
+
+ if (get_loop_loop_nr(l) == 11819)
+ dump_loop(l, "-ha-debug");
+
+ return found_problem;
+}
+
+/** Prints all loop nodes that
+ * - do not have any firm nodes, only loop sons
+ * - the header is not a Phi, Block or Filter.
+ */
+void find_strange_loop_nodes(ir_loop *l) {
+ int found_problem = 0;
+ printf("\nTesting loop "); DDML(l);
+ found_problem = test_loop_node(l);
+ printf("Finished Test\n\n");
+ if (found_problem) exit(0);
+
+}
projects / libfirm / blobdiff