#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);
- pset *df = pmap_get(df_map, bl);
- int i, n;
-
- /*
- * Create a new dom frot set for this node,
- * if none exists.
- */
- if(!df)
- pmap_insert(df_map, bl, pset_new_ptr(16));
-
- 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));
+ return idom == NULL ? bl : idom;
+}
- /* The dominance frontier set of the predecessor. */
- pset *df = pmap_get(df_map, pred);
- 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();
- assert(df && "dom front set must have been created for this node");
+ /* 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); w; 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_df(get_irg_start_block(irg), info->df_map);
- /*
- * This must be called as a post walker, since the dom front sets
- * of all predecessors must be created when a block is reached.
- */
- dom_tree_walk_irg(irg, NULL, compute_df_local, 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(ir_node *orig, 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);
+ ir_node *bl;
+ ir_node *orig_block = get_nodes_block(orig);
pdeq *worklist = new_pdeq();
- pset *phi_blocks = pset_new_ptr(8);
- ir_node **ins = NULL;
- void *it;
firm_dbg_module_t *dbg = DBG_MODULE;
- /*
- * 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);
-
- if(!block_dominates(orig_block, copy_block)) {
- assert(block_dominates(orig_block, copy_block)
- && "The block of the copy must be dominated by the block of the value");
- }
+ for(bl = pset_first(copy_blocks); bl; bl = pset_next(copy_blocks)) {
+ assert(block_dominates(orig_block, bl)
+ && "The block of the copy must be dominated by the block of the value");
- pdeq_putr(worklist, it);
- orig_blocks[i++] = copy_block;
+ pdeq_putr(worklist, bl);
}
while(!pdeq_empty(worklist)) {
- ir_node *irn = pdeq_getl(worklist);
- ir_node *bl = get_nodes_block(irn);
+ ir_node *bl = pdeq_getl(worklist);
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)) {
+ 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)) {
- 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] = new_Unknown(mode);
-
- /* Insert phi node */
- phi = new_r_Phi(irg, bl, n_preds, ins, mode);
- DBG((dbg, LEVEL_2, " inserting phi in block %+F\n", bl));
-
- /*
- * 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;
- }
+ /*
+ * 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(insert)
- pdeq_putr(worklist, y);
+ if(!pset_find_ptr(copy_blocks, y))
+ pdeq_putr(worklist, y);
}
}
}
- del_pset(phi_blocks);
del_pdeq(worklist);
-
- free(orig_blocks);
-
- if(ins)
- free(ins);
}
/**
* original node.
* @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 *phi_blocks, ir_mode *mode)
{
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_nodes_block(get_irn_n(curr_bl, 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.
*/
- start_irn = usage;
while(curr_bl != NULL) {
/*
ir_node *irn;
/* Look at each instruction from last to first. */
- for(irn = start_irn; !is_Block(irn); irn = sched_prev(irn)) {
+ sched_foreach_reverse_from(start_irn, irn) {
/* Take the first copy we find. */
if(pset_find_ptr(copies, irn))
}
}
+ else 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 = malloc(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, phi_blocks, mode);
+ DBG((dbg, LEVEL_2, "\t\t%+F(%d) -> %+F\n", phi, i, arg));
+ set_irn_n(phi, i, arg);
+ }
+ }
+
+ return phi;
+ }
+
/* If were not done yet, look in the immediate dominator */
curr_bl = get_Block_idom(curr_bl);
if(curr_bl)
return NULL;
}
-static void fix_usages(ir_node *orig, pset *copies, pset *copy_blocks)
+static void fix_usages(ir_node *orig, pset *copies, pset *copy_blocks,
+ pset *phi_blocks, pset *ignore_uses)
{
int i = 0;
int n_outs = 0;
const ir_edge_t *edge;
+ ir_mode *mode = get_irn_mode(orig);
+
firm_dbg_module_t *dbg = DBG_MODULE;
struct {
/* Count the number of outs. */
foreach_out_edge(orig, edge)
- n_outs++;
+ n_outs += !pset_find_ptr(ignore_uses, get_edge_src_irn(edge));
/*
* 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.
*/
- DBG((dbg, LEVEL_2, " Users of %+F\n", orig));
outs = malloc(n_outs * sizeof(outs[0]));
foreach_out_edge(orig, edge) {
- outs[i].irn = get_edge_src_irn(edge);
- outs[i].pos = get_edge_src_pos(edge);
- DBG((dbg, LEVEL_2, " %+F(%d)\n", outs[i].irn, outs[i].pos));
- i += 1;
+ if(!pset_find_ptr(ignore_uses, get_edge_src_irn(edge))) {
+ outs[i].irn = get_edge_src_irn(edge);
+ outs[i].pos = get_edge_src_pos(edge);
+ i += 1;
+ }
}
/*
ir_node *irn = outs[i].irn;
int pos = outs[i].pos;
- def = search_def(irn, pos, copies, copy_blocks);
+ def = search_def(irn, pos, copies, copy_blocks, phi_blocks, mode);
+ DBG((dbg, LEVEL_2, "\t%+F(%d) -> %+F\n", irn, pos, def));
+
if(def != NULL)
set_irn_n(irn, pos, def);
}
free(outs);
}
-void be_introduce_copies(dom_front_info_t *info, ir_node *orig, int n, ir_node *copy_nodes[])
+/**
+ * Remove phis which are not neccesary.
+ * 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;
+
+ for(irn = pset_first(copies); irn; irn = pset_next(copies)) {
+ if(is_Phi(irn)) {
+ int i, n;
+ int illegal = 0;
+
+ 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;
+
+ if(illegal)
+ sched_remove(irn);
+ }
+ }
+
+ for(irn = pset_first(unused_copies); irn; irn = pset_next(unused_copies)) {
+ sched_remove(irn);
+ }
+}
+
+void be_introduce_copies_ignore(dom_front_info_t *info, ir_node *orig,
+ int n, ir_node *copy_nodes[], pset *ignore_uses)
{
pset *copies = pset_new_ptr(2 * n);
pset *copy_blocks = pset_new_ptr(2 * n);
+ pset *phi_blocks = pset_new_ptr(2 * n);
int save_optimize = get_optimize();
- int i;
+ int save_normalize = get_opt_normalize();
firm_dbg_module_t *dbg = DBG_MODULE;
+ int i;
- firm_dbg_set_mask(dbg, -1);
+#if 0
+ {
+ static int ser = 0;
+ char buf[128];
+
+ snprintf(buf, sizeof(buf), "-post-%d", ser++);
+ dump_ir_block_graph_sched(get_irn_irg(orig), buf);
+ }
+#endif
+
+ firm_dbg_set_mask(dbg, DBG_LEVEL);
DBG((dbg, LEVEL_1, "Introducing following copies of %+F\n", orig));
+
/* Fill the sets. */
+ pset_insert_ptr(copies, orig);
+ pset_insert_ptr(copy_blocks, get_nodes_block(orig));
+
+ /*
+ * All phis using the original value are also copies of it
+ * and must be present in the copies set.
+ */
for(i = 0; i < n; ++i) {
DBG((dbg, LEVEL_1,
" %+F in block %+F\n", copy_nodes[i], get_nodes_block(copy_nodes[i])));
* disappear.
*/
set_optimize(0);
+ set_opt_normalize(0);
/*
* Place the phi functions and reroute the usages.
*/
- place_phi_functions(orig, copies, copy_blocks, info);
- fix_usages(orig, copies, copy_blocks);
+ determine_phi_blocks(orig, copies, copy_blocks, phi_blocks, info);
+ fix_usages(orig, copies, copy_blocks, phi_blocks, ignore_uses);
/* reset the optimizations */
set_optimize(save_optimize);
+ set_opt_normalize(save_normalize);
del_pset(copies);
+ del_pset(phi_blocks);
del_pset(copy_blocks);
+
+
+}
+
+void be_introduce_copies(dom_front_info_t *info, ir_node *orig,
+ int n, ir_node *copy_nodes[])
+{
+ static pset *empty_set = NULL;
+
+ if(!empty_set)
+ empty_set = pset_new_ptr_default();
+
+ be_introduce_copies_ignore(info, orig, n, copy_nodes, empty_set);
}
projects / libfirm / blobdiff