+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
#include <stdlib.h>
+#ifdef WIN32
+#include <malloc.h>
+#else
+#include <alloca.h>
+#endif
+
#include "hashptr.h"
#include "pdeq.h"
#include "pset.h"
#include "pmap.h"
+#include "util.h"
+#include "debug.h"
#include "irflag_t.h"
#include "ircons_t.h"
#include "irnode_t.h"
+#include "ircons_t.h"
#include "irmode_t.h"
#include "irdom_t.h"
#include "iredges_t.h"
+#include "irgopt.h"
+#include "be_t.h"
+#include "bearch.h"
#include "besched_t.h"
+#include "belive_t.h"
+#include "benode_t.h"
+#include "beutil.h"
+
#include "beirgmod.h"
+#define DBG_MODULE firm_dbg_register("firm.be.irgmod")
+#define DBG_LEVEL SET_LEVEL_0
+
struct _dom_front_info_t {
pmap *df_map;
};
-static void compute_df_local(ir_node *bl, void *data)
+/**
+ * A wrapper for get_Block_idom.
+ * This function returns the block itself, if the block is the start
+ * block. Returning NULL would make any != comparison true which
+ * suggests, that the start block is dominated by some other node.
+ * @param bl The block.
+ * @return The immediate dominator of the block.
+ */
+static INLINE ir_node *get_idom(ir_node *bl)
{
- pmap *df_map = ((dom_front_info_t *) data)->df_map;
ir_node *idom = get_Block_idom(bl);
- int i, n;
-
- for(i = 0, n = get_irn_arity(bl); i < n; ++i) {
-
- /* The predecessor block */
- ir_node *pred = get_nodes_block(get_irn_n(bl, i));
-
- /* The dominance frontier set of the predecessor. */
- pset *df = pmap_get(df_map, pred);
+ return idom == NULL ? bl : idom;
+}
- /*
- * Create the dominance frontier set of the predecessor
- * if it didn't exist.
- */
- if(!df) {
- df = pset_new_ptr(16);
- pmap_insert(df_map, pred, df);
- }
+static void compute_df(ir_node *n, pmap *df_map)
+{
+ ir_node *c;
+ const ir_edge_t *edge;
+ pset *df = pset_new_ptr_default();
+ /* Add local dominance frontiers */
+ foreach_block_succ(n, edge) {
+ ir_node *y = edge->src;
- if(pred != idom && bl)
- pset_insert_ptr(df, bl);
+ if(get_idom(y) != n)
+ pset_insert_ptr(df, y);
}
-}
-
-static void compute_df_up(ir_node *bl, void *data)
-{
- pmap *df_map = ((dom_front_info_t *) data)->df_map;
- ir_node *y;
- for(y = get_Block_dominated_first(bl); y; y = get_Block_dominated_next(y)) {
+ /*
+ * Go recursively down the dominance tree and add all blocks
+ * int the dominance frontiers of the children, which are not
+ * dominated by the given block.
+ */
+ for(c = get_Block_dominated_first(n); c; c = get_Block_dominated_next(c)) {
+ pset *df_c;
ir_node *w;
- pset *df = pmap_get(df_map, y);
- for(w = pset_first(df); df; w = pset_next(df))
- if(!block_dominates(bl, w) || bl == w)
+ compute_df(c, df_map);
+ df_c = pmap_get(df_map, c);
+
+ for(w = pset_first(df_c); w; w = pset_next(df_c)) {
+ if(get_idom(w) != n)
pset_insert_ptr(df, w);
+ }
}
+
+ pmap_insert(df_map, n, df);
+
}
dom_front_info_t *be_compute_dominance_frontiers(ir_graph *irg)
{
dom_front_info_t *info = malloc(sizeof(*info));
+ edges_assure(irg);
info->df_map = pmap_create();
+ compute_doms(irg);
+ compute_df(get_irg_start_block(irg), info->df_map);
- /* Perhaps both can we interwined */
- dom_tree_walk_irg(irg, compute_df_local, NULL, info);
- dom_tree_walk_irg(irg, NULL, compute_df_up, info);
return info;
}
return pmap_get(info->df_map, block);
}
-/**
- * Algorithm to place the Phi-Functions.
- * @see Appel, Modern Compiler Implementation in Java, 2nd ed., p. 399ff
- *
- * This function takes an original node and a set of already placed
- * copies of that node called @p copies. It places phi nodes at the
- * iterated dominance frontiers of these copies and puts these phi nodes
- * in the @p copies set, since they are another form of copies of the
- * original value.
- *
- * The rename phase (see below) is responsible for fixing up the usages
- * of the original node.
- *
- * @param orig The original node.
- * @param copies A set contianing nodes representing a copy of the
- * original node. Each node must be inserted into the block's schedule.
- * @param copy_blocks A set in which the blocks are recorded which
- * contain a copy. This is just for efficiency in later phases (see
- * rename).
- */
-static void place_phi_functions(ir_node *orig, pset *copies,
- pset *copy_blocks, dom_front_info_t *df_info)
+static void determine_phi_blocks(pset *copies, pset* copy_blocks, pset *phi_blocks, dom_front_info_t *df_info)
{
- int i;
- ir_node *orig_block = get_nodes_block(orig);
- ir_graph *irg = get_irn_irg(orig);
- ir_mode *mode = get_irn_mode(orig);
- pdeq *worklist = new_pdeq();
- pset *phi_blocks = pset_new_ptr(8);
- ir_node **ins = NULL;
- void *it;
-
- /*
- * Allocate an array for all blocks where the copies and the original
- * value were defined.
- */
- int n_orig_blocks = pset_count(copy_blocks) + 1;
- ir_node **orig_blocks = malloc(n_orig_blocks * sizeof(orig_blocks[0]));
-
- /*
- * Fill the array of definition blocks.
- */
- orig_blocks[0] = get_nodes_block(orig);
-
- /*
- * Fill the worklist queue and the rest of the orig blocks array.
- */
- for(it = pset_first(copies), i = 1; it; it = pset_next(copies)) {
- ir_node *copy_block = get_nodes_block(it);
-
- assert(block_dominates(orig_block, copy_block)
- && "The block of the copy must be dominated by the block of the value");
-
- pdeq_putr(worklist, it);
- orig_blocks[i++] = copy_block;
- }
-
- while(!pdeq_empty(worklist)) {
- ir_node *irn = pdeq_getl(worklist);
- ir_node *bl = get_nodes_block(irn);
- ir_node *y;
- int n_preds = get_irn_arity(bl);
- pset *df = be_get_dominance_frontier(df_info, bl);
-
- for(y = pset_first(df); y; y = pset_next(df)) {
-
- if(!pset_find_ptr(phi_blocks, y)) {
- ir_node *phi;
- int insert = 1;
-
- /*
- * Set the orig node as the only operand of the
- * phi node.
- */
- ins = realloc(ins, n_preds * sizeof(ins[0]));
- for(i = 0; i < n_preds; ++i)
- ins[0] = orig;
-
- /* Insert phi node */
- phi = new_r_Phi(irg, bl, n_preds, ins, mode);
-
- /*
- * The phi node itself is also a copy of the original
- * value. So put it in the copies set also, so that
- * the rename phase can treat them right.
- */
- pset_insert_ptr(copies, phi);
- pset_insert_ptr(copy_blocks, y);
-
- /* Insert the phi node into the schedule */
- sched_add_before(sched_first(y), phi);
-
- /* Insert the phi node in the phi blocks set. */
- pset_insert_ptr(phi_blocks, y);
-
- /*
- * If orig or a copy of it were not defined in y,
- * add y to the worklist.
- */
- for(i = 0; i < n_orig_blocks; ++i)
- if(orig_blocks[i] == y) {
- insert = 0;
- break;
- }
-
- if(insert)
- pdeq_putr(worklist, y);
-
- }
- }
- }
-
- del_pset(phi_blocks);
- del_pdeq(worklist);
-
- free(orig_blocks);
-
- if(ins)
- free(ins);
+ ir_node *bl;
+ pdeq *worklist = new_pdeq();
+ firm_dbg_module_t *dbg = DBG_MODULE;
+
+ /*
+ * Fill the worklist queue and the rest of the orig blocks array.
+ */
+ for(bl = pset_first(copy_blocks); bl; bl = pset_next(copy_blocks)) {
+ pdeq_putr(worklist, bl);
+ }
+
+ while(!pdeq_empty(worklist)) {
+ ir_node *bl = pdeq_getl(worklist);
+ pset *df = be_get_dominance_frontier(df_info, bl);
+
+ ir_node *y;
+
+ DBG((dbg, LEVEL_3, "dom front of %+F\n", bl));
+ for(y = pset_first(df); y; y = pset_next(df))
+ DBG((dbg, LEVEL_3, "\t%+F\n", y));
+
+ for(y = pset_first(df); y; y = pset_next(df)) {
+ if(!pset_find_ptr(phi_blocks, y)) {
+ pset_insert_ptr(phi_blocks, y);
+
+ /*
+ * Clear the link field of a possible phi block, since
+ * the possibly created phi will be stored there. See,
+ * search_def()
+ */
+ set_irn_link(y, NULL);
+
+ if(!pset_find_ptr(copy_blocks, y))
+ pdeq_putr(worklist, y);
+
+ }
+ }
+ }
+
+ del_pdeq(worklist);
}
/**
* traversing from the predecessor block which corresponds to the phi
* usage.
*
- * @param usage The node which uses the original node.
- * @param pos The number of the argument which corresponds to the
- * original node.
- * @param copy_blocks A set containing all basic block in which copies
- * of the original node are located.
- * @param copies A set containing all node which are copies from the
- * original node.
- * @return The valid copy for usage.
+ * @param usage The node which uses the original node.
+ * @param pos The position of the argument which corresponds to the original node.
+ * @param copies A set containing all node which are copies from the original node.
+ * @param copy_blocks A set containing all basic block in which copies of the original node are located.
+ * @param phis A set where all created phis are recorded.
+ * @param phi_blocks A set of all blocks where Phis shall be inserted (iterated dominance frontier).
+ * @param mode The mode for the Phi if one has to be created.
+ * @return The valid copy for usage.
*/
-static ir_node *search_def(ir_node *usage, int pos, pset *copies, pset *copy_blocks)
+static ir_node *search_def(ir_node *usage, int pos, pset *copies, pset *copy_blocks, pset *phis, pset *phi_blocks, ir_mode *mode)
{
- ir_node *curr_bl;
-
- curr_bl = get_nodes_block(usage);
-
- /*
- * If the usage is in a phi node, search the copy in the
- * predecessor denoted by pos.
- */
- if(is_Phi(usage))
- curr_bl = get_nodes_block(get_irn_n(curr_bl, pos));
+ ir_node *curr_bl;
+ ir_node *start_irn;
+ firm_dbg_module_t *dbg = DBG_MODULE;
+
+ curr_bl = get_nodes_block(usage);
+
+ DBG((dbg, LEVEL_1, "Searching valid def for use %+F at pos %d\n", usage, pos));
+ /*
+ * If the usage is in a phi node, search the copy in the
+ * predecessor denoted by pos.
+ */
+ if(is_Phi(usage)) {
+ curr_bl = get_Block_cfgpred_block(curr_bl, pos);
+ start_irn = sched_last(curr_bl);
+ } else {
+ start_irn = sched_prev(usage);
+ }
+
+ /*
+ * Traverse the dominance tree upwards from the
+ * predecessor block of the usage.
+ */
+ while(curr_bl != NULL) {
+
+ /*
+ * If this block contains a copy, search the block
+ * instruction by instruction.
+ */
+ if(pset_find_ptr(copy_blocks, curr_bl)) {
+ ir_node *irn;
+
+ /* Look at each instruction from last to first. */
+ sched_foreach_reverse_from(start_irn, irn) {
+
+ /* Take the first copy we find. */
+ if(pset_find_ptr(copies, irn))
+ return irn;
+ }
+ }
+
+ if(pset_find_ptr(phi_blocks, curr_bl)) {
+ ir_node *phi = get_irn_link(curr_bl);
+
+ if(!phi) {
+ int i, n_preds = get_irn_arity(curr_bl);
+ ir_graph *irg = get_irn_irg(curr_bl);
+ ir_node **ins = xmalloc(n_preds * sizeof(ins[0]));
+
+ for(i = 0; i < n_preds; ++i)
+ ins[i] = new_r_Unknown(irg, mode);
+
+ phi = new_r_Phi(irg, curr_bl, n_preds, ins, mode);
+ DBG((dbg, LEVEL_2, "\tcreating phi %+F in %+F\n", phi, curr_bl));
+
+ set_irn_link(curr_bl, phi);
+ sched_add_after(curr_bl, phi);
+ free(ins);
+
+ for(i = 0; i < n_preds; ++i) {
+ ir_node *arg = search_def(phi, i, copies, copy_blocks, phis, phi_blocks, mode);
+ DBG((dbg, LEVEL_2, "\t\t%+F(%d) -> %+F\n", phi, i, arg));
+ set_irn_n(phi, i, arg);
+ }
+
+ if(phis)
+ pset_insert_ptr(phis, phi);
+ }
+
+ return phi;
+ }
+
+ /* If were not done yet, look in the immediate dominator */
+ curr_bl = get_Block_idom(curr_bl);
+ if(curr_bl)
+ start_irn = sched_last(curr_bl);
+ }
+
+ return NULL;
+}
- /*
- * Traverse the dominance tree upwards from the
- * predecessor block of the usage.
- */
- while(curr_bl != NULL) {
+static void fix_usages(pset *copies, pset *copy_blocks, pset *phi_blocks, pset *phis, pset *ignore_uses)
+{
+ firm_dbg_module_t *dbg = DBG_MODULE;
+ int n_outs = 0;
+
+ struct obstack obst;
+ ir_node *irn;
+ int i;
+
+ struct out {
+ ir_node *irn;
+ int pos;
+ } *outs;
+
+ obstack_init(&obst);
+
+ /*
+ * Put all outs into an array.
+ * This is necessary, since the outs would be modified while
+ * iterating on them what could bring the outs module in trouble.
+ */
+ for(irn = pset_first(copies); irn; irn = pset_next(copies)) {
+ const ir_edge_t *edge;
+ foreach_out_edge(irn, edge) {
+ if(!pset_find_ptr(ignore_uses, get_edge_src_irn(edge))) {
+ struct out tmp;
+ tmp.irn = get_edge_src_irn(edge);
+ tmp.pos = get_edge_src_pos(edge);
+ obstack_grow(&obst, &tmp, sizeof(tmp));
+ n_outs++;
+ }
+ }
+ }
+ outs = obstack_finish(&obst);
+
+ /*
+ * Search the valid def for each out and set it.
+ */
+ for(i = 0; i < n_outs; ++i) {
+ ir_node *irn = outs[i].irn;
+ int pos = outs[i].pos;
+ ir_mode *mode = get_irn_mode(get_irn_n(irn, pos));
+
+ ir_node *def;
+
+ def = search_def(irn, pos, copies, copy_blocks, phis, phi_blocks, mode);
+ DBG((dbg, LEVEL_2, "\t%+F(%d) -> %+F\n", irn, pos, def));
+
+ if(def != NULL)
+ set_irn_n(irn, pos, def);
+ }
+
+ obstack_free(&obst, NULL);
+}
- /*
- * If this block contains a copy, search the block
- * instruction by instruction.
- */
- if(pset_find_ptr(copy_blocks, curr_bl)) {
- ir_node *irn;
+/**
+ * Remove phis which are not necessary.
+ * During place_phi_functions() phi functions are put on the dominance
+ * frontiers blindly. However some of them will never be used (these
+ * have at least one predecessor which is NULL, see search_def() for
+ * this case). Since place_phi_functions() enters them into the
+ * schedule, we have to remove them from there.
+ *
+ * @param copies The set of all copies made (including the phi functions).
+ */
+static void remove_odd_phis(pset *copies, pset *unused_copies)
+{
+ ir_node *irn;
- /* Look at each instruction from last to first. */
- sched_foreach_reverse(curr_bl, irn) {
+ for(irn = pset_first(copies); irn; irn = pset_next(copies)) {
+ if(is_Phi(irn)) {
+ int i, n;
+ int illegal = 0;
- /* Take the first copy we find. */
- if(pset_find_ptr(copies, irn))
- return irn;
- }
+ assert(sched_is_scheduled(irn) && "phi must be scheduled");
+ for(i = 0, n = get_irn_arity(irn); i < n && !illegal; ++i)
+ illegal = get_irn_n(irn, i) == NULL;
- assert(0 && "We must have encountered a copy");
+ if(illegal)
+ sched_remove(irn);
}
-
- /* If were not done yet, look in the immediate dominator */
- curr_bl = get_Block_idom(curr_bl);
}
- return NULL;
+ for(irn = pset_first(unused_copies); irn; irn = pset_next(unused_copies)) {
+ sched_remove(irn);
+ }
}
-
-static void fix_usages(ir_node *orig, pset *copies, pset *copy_blocks)
+void be_ssa_constr_phis_ignore(dom_front_info_t *info, int n, ir_node *nodes[], pset *phis, pset *ignore_uses)
{
- int i;
- int n_outs = 0;
- const ir_edge_t *edge;
- const ir_edge_t **outs;
+ pset *irns = pset_new_ptr(n);
+ int i;
- /* Count the number of outs. */
- foreach_out_edge(orig, edge)
- n_outs++;
+ for(i = 0; i < n; ++i)
+ pset_insert_ptr(irns, nodes[i]);
+ be_ssa_constr_set_phis_ignore(info, irns, phis, ignore_uses);
+ del_pset(irns);
+}
- /*
- * Put all outs into an array.
- * This is neccessary, since the outs would be modified while
- * interating on them what could bring the outs module in trouble.
- */
- outs = malloc(n_outs * sizeof(outs[0]));
- foreach_out_edge(orig, edge)
- outs[i++] = edge;
+void be_ssa_constr_ignore(dom_front_info_t *info, int n, ir_node *nodes[], pset *ignore_uses)
+{
+ be_ssa_constr_phis_ignore(info, n, nodes, NULL, ignore_uses);
+}
- /*
- * Search the valid def for each out and set it.
- */
- for(i = 0; i < n_outs; ++i) {
- ir_node *def;
- ir_node *irn = get_edge_src_irn(outs[i]);
- int pos = get_edge_src_pos(outs[i]);
+void be_ssa_constr(dom_front_info_t *info, int n, ir_node *nodes[])
+{
+ pset *empty_set = be_empty_set();
+ assert(pset_count(empty_set) == 0);
+ be_ssa_constr_ignore(info, n, nodes, empty_set);
+}
- def = search_def(irn, pos, copies, copy_blocks);
- set_irn_n(irn, pos, def);
- }
+void be_ssa_constr_set_phis_ignore(dom_front_info_t *df, pset *nodes, pset *phis, pset *ignore_uses)
+{
+ int n = pset_count(nodes);
+ pset *blocks = pset_new_ptr(n);
+ pset *phi_blocks = pset_new_ptr(n);
+ int save_optimize = get_optimize();
+ int save_normalize = get_opt_normalize();
+ firm_dbg_module_t *dbg = DBG_MODULE;
+
+ ir_node *irn;
+
+ firm_dbg_set_mask(dbg, DBG_LEVEL);
+ DBG((dbg, LEVEL_1, "Introducing following copies for:\n"));
+
+ /* Fill the sets. */
+ for(irn = pset_first(nodes); irn; irn = pset_next(nodes)) {
+ ir_node *bl = get_nodes_block(irn);
+ pset_insert_ptr(blocks, bl);
+ DBG((dbg, LEVEL_1, "\t%+F in %+F\n", irn, bl));
+ }
+
+ /*
+ * Disable optimization so that the phi functions do not
+ * disappear.
+ */
+ set_optimize(0);
+ set_opt_normalize(0);
+
+ /*
+ * Place the phi functions and reroute the usages.
+ */
+ determine_phi_blocks(nodes, blocks, phi_blocks, df);
+ fix_usages(nodes, blocks, phi_blocks, phis, ignore_uses);
+
+ /* reset the optimizations */
+ set_optimize(save_optimize);
+ set_opt_normalize(save_normalize);
+
+ del_pset(phi_blocks);
+ del_pset(blocks);
- free(outs);
}
-void be_introduce_copies(dom_front_info_t *info, ir_node *orig, int n, ir_node *copy_nodes[])
+void be_ssa_constr_set_phis(dom_front_info_t *df, pset *nodes, pset *phis)
{
- pset *copies = pset_new_ptr(2 * n);
- pset *copy_blocks = pset_new_ptr(2 * n);
- int save_optimize = get_optimize();
- int i;
-
- /* Fill the sets. */
- for(i = 0; i < n; ++i) {
- pset_insert_ptr(copies, copy_nodes[i]);
- pset_insert_ptr(copy_blocks, get_nodes_block(copy_nodes[i]));
- }
+ pset *empty_set = be_empty_set();
+ assert(pset_count(empty_set) == 0);
- /*
- * Disable optimization so that the phi functions do not
- * disappear.
- */
- set_optimize(0);
-
- /*
- * Place the phi functions and reroute the usages.
- */
- place_phi_functions(orig, copies, copy_blocks, info);
- fix_usages(orig, copies, copy_blocks);
+ be_ssa_constr_set_phis_ignore(df, nodes,phis, empty_set);
+}
- /* reset the optimizations */
- set_optimize(save_optimize);
+void be_ssa_constr_set_ignore(dom_front_info_t *df, pset *nodes, pset *ignore_uses)
+{
+ be_ssa_constr_set_phis_ignore(df, nodes, NULL, ignore_uses);
+}
- del_pset(copies);
- del_pset(copy_blocks);
+void be_ssa_constr_set(dom_front_info_t *info, pset *nodes)
+{
+ pset *empty_set = be_empty_set();
+ assert(pset_count(empty_set) == 0);
+ be_ssa_constr_set_ignore(info, nodes, empty_set);
}
projects / libfirm / blobdiff