#include <stdlib.h>
+#include "obst.h"
+#include "pset.h"
#include "bitset.h"
#include "debug.h"
+
#include "bechordal.h"
#include "belive.h"
-
#include "bera_t.h"
#include "bephicongr_t.h"
#include "bephicoal_t.h"
#define DEBUG_LVL 1
#define MAX_PHI_CLS_SIZE (1<<(sizeof(unsigned char)*8)) /* possible colors added should fit into unsigned char */
-#define MAX_COLORS 16
-
-
-static firm_dbg_module_t *dbgphi = NULL;
-
-
-typedef enum _live_status_t {
- livein = 1,
- liveout = 2
-} live_status_t;
+#define MAX_COLORS 32
+#define CHANGE_IMPOSSIBLE -1
+#define CHANGE_SAVE 1
+#define DRYRUN 1
+#define PERFORM 0
typedef struct _phi_unit_t {
unsigned char count;
unsigned char phi_count;
- ir_node **members; /* [0..phi_count-1] are phi nodes. [phi_count..count-1] the rest/arguments of the phis */
- bitset_t **used_cols;
- int *tgt_colors; /* [i] is the color to set for members[i]. [i] == -1 means dont change anything for members[i]*/
- live_status_t *live_info; /* [i] says how/where members[i] is live */
+
+ /* 1 phi */
+ ir_node **members; /**< [0] is the phi node. [1..count-1] the arguments of the phi not interfering with it */
+ int *colors; /**< [i] is the color to set for members[i]. [i] == NO_COLOR means dont change anything for members[i]*/
+ char *is_live_in; /**< [i]==1 means members[i] is live-in in (all of) its cf-pred-blocks of the phi node */
+ int size; /**< size of the max independent set of members. The set is markes by colors[i] != NO_COLOR */
+ int changes; /**< number of re-assigned nodes belonging to phi-classes */
} phi_unit_t;
-static pset *done;
+static firm_dbg_module_t *dbgphi = NULL;
+/**
+ * Contains ir_nodes of phi-classes whose colors were reassigned during coalescing.
+ * So one can check not to switch them twice or more.
+ */
+static pset *pinned_nodes = NULL;
-static INLINE void set_color(ir_node *irn, int col) {
- if (!pset_find_ptr(done, irn)) {
- set_irn_color(irn, col);
- pset_insert_ptr(done, irn);
- }
-}
+/**
+ * Contains ir_nodes of phi-classes whose colors may change unlimited times.
+ * These nodes are not optimizable, so there is no need to pin their color.
+ */
+static pset *free_nodes = NULL;
-static void coalesce(phi_unit_t *pu) {
- int i;
- if (pu->phi_count != 1) {
- DBG((dbgphi, 1, "Dropped: phicount\n"));
- return;
- }
-#if 0
+/* TODO: ask/check if additional ir_node-space is initialized with 0000 */
+#define belongs_to_a_phi_class(n) (get_irn_phi_info(n)->phi)
- done = pset_new_ptr(64);
+#define is_color_free(bl,col) (!bitset_is_set(get_ra_block_info(bl)->used_colors, col))
- for (i = 0; i < pu->count; ++i)
- if (pu->live_info[i] & livein) {
- DBG((dbgphi, 1, "Dropped: live-in\n"));
- return;
- }
+/**
+ * Set the color of node @p n to @p col, but acts
+ * pinning aware.
+ */
+static INLINE void set_color(ir_node *n, int col) {
+ assert(!pset_find_ptr(pinned_nodes, n));
+ set_irn_color(n, col);
+ if (belongs_to_a_phi_class(n) && !pset_find_ptr(free_nodes, n))
+ pset_insert_ptr(pinned_nodes, n);
+}
- for (i = 0; i < pu->count; ++i) {
- block_list_t *bl;
+/**
+ * Tries to set the color of @p n to @p col.
+ * @param n The node to set the color for
+ * @param col The color to set.
+ * @param dryrun If true no colors are actually set, only testing is performed.
+ * If false colors get set and it must be sure that no conflicts will occur.
+ * @return If setting the color is impossible CHANGE_IMPOSSIBLE is returned
+ * else the number of nodes that need a (cascading) change is returned.
+ */
+static int color_irn(ir_node *n, int col, int dryrun) {
+ ir_node *bl;
+ int res = 0;
+ DBG((dbgphi, 1, "\t\t\t\t%n %d\n", n, col));
+ assert(is_color(col));
+
+ if (get_irn_color(n) == col) {
+ DBG((dbgphi, 1, "\t\t\t\t\tSame\n"));
+ return 0;
+ }
- if (pu->tgt_colors[i] == -1)
- continue;
+ if (pset_find_ptr(pinned_nodes, n)) {
+ DBG((dbgphi, 1, "\t\t\t\t\tPinned\n"));
+ if (!dryrun)
+ assert(0 && "No prior check with dryrun=1 or buggy");
+ return CHANGE_IMPOSSIBLE;
+ }
- /* TODO: if we move ahead to swapping (not just allocating new colors) this is wrong */
- set_color(pu->members[i], pu->tgt_colors[i]);
- if (pu->live_info[i] & liveout) {
- bl = get_dominated_dfs(get_nodes_block(pu->members[i]));
- }
+ bl = get_nodes_block(n);
+ if (is_color_free(bl, col) && !is_live_out(bl, n)) {
+ DBG((dbgphi, 1, "\t\t\t\t\tFree\n"));
+ if (!dryrun)
+ set_color(n, col);
+ return 1;
}
- del_pset(done);
+ /* for now, in the aldi-version return impossible */
+ DBG((dbgphi, 1, "\t\t\t\t\tImpossible\n"));
+ return CHANGE_IMPOSSIBLE;
-#endif
+ return res;
}
-static void ana_1_phi(phi_unit_t *pu) {
- ir_node *phi, *phi_blk;
- int i, o, n, col, best_color, size, best_size;
- ir_node **cand, **max_set, **best_max_set;
-
- cand = malloc(pu->count * sizeof(ir_node*));
- max_set = malloc(pu->count * sizeof(ir_node*));
- best_max_set = malloc(pu->count * sizeof(ir_node*));
+/**
+ * Tries to set as much members of a phi unit as possible to color @p col.
+ */
+static void try_colors(phi_unit_t *pu, int col, int b_size, int b_changes) {
+ struct obstack ob;
+ int i, o, cand_size, mis_size, changes;
+ ir_node **cand, **mis;
- phi = pu->members[0];
- phi_blk = get_nodes_block(phi);
+ cand_size = 0;
+ obstack_init(&ob);
+ /* first init pessimistically, so we can just return
+ * if we see there wont be a better result */
+ pu->size = 0;
+ for (i = 0; i < pu->count; ++i)
+ pu->colors[i] = NO_COLOR;
- /* fill live_info */
- DBG((dbgphi, 1, "\tLiveness info\n"));
- /* first the phi */
- if (is_live_out(phi_blk, phi)) {
- pu->live_info[0] = liveout;
- DBG((dbgphi, 1, "\t\t%n lives out\n", phi));
+ /* For all members check if color would be possible.
+ * Does not check if color is possible in combination with
+ * other members colors being set */
+ changes = 0;
+ for (i = 0; i < pu->count; ++i) {
+ int tmp_changes = color_irn(pu->members[i], col, DRYRUN);
+ if (tmp_changes != CHANGE_IMPOSSIBLE) {
+ DBG((dbgphi, 1, "\t\t\tAdding to cand %n\n", pu->members[i]));
+ obstack_ptr_grow(&ob, pu->members[i]);
+ cand_size++;
+ changes += tmp_changes;
+ }
+ /* if color is not possible for the phi node then exit (phi comes first)*/
+ if (cand_size == 0)
+ goto ret;
}
-
- /* then all args */
- for (i = 0, n = get_irn_arity(phi); i < n; ++i) {
- int midx;
- ir_node *arg, *block_ith_pred;
-
- arg = get_irn_n(phi, i);
- block_ith_pred = get_nodes_block(get_irn_n(phi_blk, i));
-
- /* find the arg in the members array */
- midx = -1;
- for (o = 0; o < pu->count; ++o)
- if (pu->members[o] == arg) {
- midx = o;
+ cand = obstack_finish(&ob);
+
+ /* shortcut: if cand is worse than best the mis wont be better. */
+ if (cand_size < b_size || (cand_size == b_size && changes >= b_changes))
+ goto ret;
+
+ /* now take the candidates cand and determine a max independent set
+ * with respect to edges representing live range interference */
+ /* TODO: make this 'un-greedy' */
+ mis_size = 0;
+ for (i = 0; i < cand_size; ++i) {
+ int intf_det = 0;
+ for (o = 0; o < mis_size; ++o) {
+ mis = (ir_node**) obstack_base(&ob);
+ if (values_interfere(cand[i], mis[o])) {
+ intf_det = 1;
break;
}
- assert(midx != -1 && "All args have to be in the members!\n");
-
- if (is_live_in(block_ith_pred, arg)) {
- pu->live_info[midx] |= livein;
- DBG((dbgphi, 1, "\t\t%n lives in\n", arg));
}
- if (is_live_out(block_ith_pred, arg)) {
- pu->live_info[midx] |= liveout;
- DBG((dbgphi, 1, "\t\t%n lives out\n", arg));
+ if (!intf_det) {
+ DBG((dbgphi, 1, "\t\t\tAdding to mis %n\n", cand[i]));
+ obstack_ptr_grow(&ob, cand[i]);
+ mis_size++;
}
}
+ mis = obstack_finish(&ob);
+
+ /* Now set the colors of all nodes in the mis to col.
+ * - Each change taken alone is conflict free.
+ * - If all members are not live-in in their cf-pred-blocks there will be no
+ * conflict applying all changes
+ * - If there is a member, which is live-in in its cf-pred-block of the phi
+ * node, it is possible that all changes together will conflict.
+ */
+ for (i = 0; i < pu->count; ++i)
+ for (o = 0; o < mis_size; ++o)
+ if (pu->members[i] == mis[o] && get_irn_color(pu->members[i]) != col)
+ pu->colors[i] = col;
- /* find best color */
- best_size = -1;
- for (col = 0; col < MAX_COLORS; ++col) { /* TODO: try phi color first */
- DBG((dbgphi, 1, "\tTesting colors %d\n", col));
-
- memset(cand, 0, pu->count * sizeof(ir_node*));
- memset(max_set, 0, pu->count * sizeof(ir_node*));
-
- /* BETTER: Alle die mit dem phi interferieren koennen eigentlich
- * schon frueher raus, da unabhaengig von Farbe. */
- /* for this color get all potential candidates for a max indep. set */
- cand[0] = phi;
- size = 1;
- for (i = 1; i < pu->count; ++i)
- if ((!bitset_is_set(pu->used_cols[i], col) || get_irn_color(pu->members[i]) == col)
- && !phi_ops_interfere(phi, pu->members[i])) {
- /* color is free or already used by the node
- * and argument is not interfering with phi */
- cand[i] = pu->members[i];
- DBG((dbgphi, 1, "\t\tAdding candidate %n\n", cand[i]));
- size++;
- }
- if (size <= best_size) {
- /* If the candidate set is smaller the max indep. set wont be larger :) */
- continue;
- }
+ret:
+ obstack_free(&ob, NULL);
+}
- /* determine the max indep. set */
- /* TODO: make this 'un-greedy' */
- size = 0;
- for (i = 0; i < pu->count; ++i) {
- int intf_det = 0;
- if (!cand[i])
- continue;
- for (o = 0; o < pu->count; ++o) {
- if (!max_set[o])
- continue;
- if (phi_ops_interfere(cand[i], max_set[o])) {
- DBG((dbgphi, 1, "\t\t\n"));
- intf_det = 1;
- break;
- }
- }
+/**
+ * Sets the colors of members[i] to colors[i] as far as possible.
+ * Each single change must be conflict free (checked by try_colors).
+ * In some cases not all colors can be set.
+ */
+static void set_colors(phi_unit_t *pu) {
+ int i;
+ int change_is_save, live_in_occured = 0;
- if (!intf_det) {
- DBG((dbgphi, 1, "\t\tAdding to set %n\n", cand[i]));
- max_set[i] = cand[i];
- size++;
+ for (i = 0; i < pu->count; ++i)
+ if (pu->colors[i] != NO_COLOR) {
+ if (pu->is_live_in[i])
+ live_in_occured = 1;
+
+ change_is_save = CHANGE_SAVE;
+ if (live_in_occured)
+ change_is_save = color_irn(pu->members[i], pu->colors[i], DRYRUN);
+
+ /* HINT: Dont change to == CHANGE_SAVE */
+ if (change_is_save != CHANGE_IMPOSSIBLE) {
+ DBG((dbgphi, 1, "\t\tSetting %n to %d\n", pu->members[i], pu->colors[i]));
+ color_irn(pu->members[i], pu->colors[i], PERFORM);
+ } else {
+ DBG((dbgphi, 1, "\t\tConflict due to a live-in: %n\n", pu->members[i]));
}
}
+}
- DBG((dbgphi, 1, "\t\tColor %d resulted in a set size of %d\n", col, size));
-
- /* Did we find a better max set? */
- if (size > best_size) {
- void *tmp;
-
- best_color = col;
- best_size = size;
+/**
+ * Tries to re-allocate colors of this phi-class, to achieve a lower number of
+ * copies placed during phi destruction. Optimized version. Works only for
+ * phi-classes/phi-units with exactly 1 phi node, which is the case for approx.
+ * 80%.
+ */
+static void coalesce_1_phi(phi_unit_t *pu) {
+ int *b_colors, b_size, b_changes, b_color;
+ int i, col;
- tmp = best_max_set;
- best_max_set = max_set;
- max_set = tmp;
+ /* init best search result */
+ b_colors = malloc(pu->count * sizeof(*b_colors));
+ for (i = 0; i < pu->count; ++i)
+ b_colors[i] = NO_COLOR;
+ b_size = 0;
+ b_changes = 0;
+ b_color = NO_COLOR;
+
+ /* find optimum of all colors */
+ for (col = MAX_COLORS-1; col >= 0; --col) {
+ DBG((dbgphi, 1, "\tTrying color %d\n", col));
+ try_colors(pu, col, b_size, b_changes);
+
+ /* did we find a better max ind. set? */
+ if (pu->size > b_size || (pu->size == b_size && pu->changes < b_changes)) {
+ b_size = pu->size;
+ b_changes = pu->changes;
+ b_color = col;
+ memcpy(b_colors, pu->colors, pu->count * sizeof(*b_colors));
+ DBG((dbgphi, 1, "\t\tBetter! Size: %d Changes: %d\n", b_size, b_changes));
}
- /* Is this a best possible set? */
- /* BETTER: Find a better lower bound than pu->count, considering interferences */
- if (best_size == pu->count)
+ /* shortcut: if all members can be colored we are content and doubt that
+ * reducing b_changes justifies all the further trying. */
+ if (b_size == pu->count)
break;
}
- DBG((dbgphi, 1, "Best color was %d. %d of %d copies needed.\n", best_color, pu->count-best_size, pu->count-1));
+ /* now apply the found optimum */
+ DBG((dbgphi, 1, "\tBest color: %d Copies: %d/%d Changes: %d\n", b_color, pu->count-b_size, pu->count, b_changes));
+ pu->size = b_size;
+ pu->changes = b_changes;
+ memcpy(pu->colors, b_colors, pu->count * sizeof(*b_colors));
+ set_colors(pu);
- /* now we have the best_max_set with its best_size
- * so set the tgt_colors */
- for (i = 0; i < pu->count; ++i)
- if (best_max_set[i] && get_irn_color(best_max_set[i]) != best_color)
- pu->tgt_colors[i] = best_color;
- else
- pu->tgt_colors[i] = -1;
-
- free(cand);
- free(max_set);
- free(best_max_set);
+ free(b_colors);
}
+/**
+ * Tries to re-allocate colors of this phi-class, to achieve a lower number of
+ * copies placed during phi destruction. General purpose version.
+ */
+static void coalesce_n_phi(phi_unit_t *pu) {
+ DBG((dbgphi, 1, "\n"));
+ /* TODO */
+}
+/**
+ * Prepare a phi class for further processing as a phi unit.
+ */
static phi_unit_t *new_phi_unit(pset *pc) {
phi_unit_t *pu;
- int i, o;
- ir_node *n;
+ ir_node *n, *phi = NULL;
assert(pset_count(pc) <= MAX_PHI_CLS_SIZE && "Phi class too large!");
- pu = malloc(sizeof(phi_unit_t));
- pu->count = pset_count(pc);
- pu->members = malloc(pu->count * sizeof(*pu->members));
- pu->used_cols = malloc(pu->count * sizeof(bitset_t*));
- pu->tgt_colors = malloc(pu->count * sizeof(int));
- pu->live_info = calloc(pu->count, sizeof(ir_node*));
-
-
- /* fill the members array */
- DBG((dbgphi, 1, "Phi class:\n"));
- i = 0;
- o = pu->count-1;
- for (n = (ir_node *)pset_first(pc); n; n = (ir_node *)pset_next(pc)) {
- DBG((dbgphi, 1, "\t%n\n", n));
- if (is_Phi(n))
- pu->members[i++] = n;
- else
- pu->members[o--] = n;
- }
- pu->phi_count = i;
- DBG((dbgphi, 1, "\n"));
-
+ pu = malloc(sizeof(*pu));
+ pu->phi_count = 0;
+ for (n = pset_first(pc); n; n = pset_next(pc))
+ if (is_Phi(n)) {
+ phi = n;
+ pu->phi_count++;
+ }
- /* fill used colors array */
- for (i = 0; i < pu->count; ++i)
- pu->used_cols[i] = get_ra_block_info(get_nodes_block(pu->members[i]))->used_colors;
+ if (pu->phi_count == 1) {
+ ir_node **tmp, *phi_block;
+ int i, max;
+ struct obstack ob;
+
+ obstack_init(&ob);
+
+ /* build member set not containing phi interferers */
+ DBG((dbgphi, 1, "Phi-1 class:\n"));
+ pu->count = 1; /*for the phi*/
+ for (n = pset_first(pc); n; n = pset_next(pc)) {
+ if (!is_Phi(n) && !values_interfere(phi, n)) {
+ DBG((dbgphi, 1, "\tAdding to members: %n\n", n));
+ obstack_ptr_grow(&ob, n);
+ pu->count++;
+ } else {
+ DBG((dbgphi, 1, "\tPhi interferer: %n\n", n));
+ pset_insert_ptr(free_nodes, n);
+ }
+ }
+ tmp = obstack_finish(&ob);
+ pu->members = malloc(pu->count * sizeof(*pu->members));
+ pu->members[0] = phi;
+ memcpy(&pu->members[1], tmp, (pu->count-1) * sizeof(*tmp));
+
+ /* init of colors array */
+ pu->colors = malloc(pu->count * sizeof(*pu->colors));
+
+ /* live-in analysis */
+ /* HINT: It is possible that a node occurs twice as arg of a phi,
+ * one time being live-in, and another time not being live-in.
+ */
+ pu->is_live_in = calloc(pu->count, sizeof(*pu->is_live_in));
+ phi_block = get_nodes_block(phi);
+ for (i = 0, max = get_irn_arity(phi); i < max; ++i) {
+ int midx, o;
+ ir_node *arg, *block_ith_pred;
+
+ arg = get_irn_n(phi, i);
+ block_ith_pred = get_nodes_block(get_irn_n(phi_block, i));
+
+ /* find the arg in the members array */
+ midx = -1;
+ for (o = 0; o < pu->count; ++o)
+ if (pu->members[o] == arg) {
+ midx = o;
+ break;
+ }
+ if (midx == -1)
+ continue;
+ if (is_live_in(block_ith_pred, arg)) {
+ pu->is_live_in[midx] |= 1;
+ DBG((dbgphi, 1, "\t%n is live-in in %n\n", arg, block_ith_pred));
+ }
+ }
- if (pu->phi_count == 1) {
- ana_1_phi(pu);
+ obstack_free(&ob, NULL);
} else {
+ DBG((dbgphi, 1, "Phi-n class:\n"));
/* TODO */
- // ana_n_phi(pu);
}
+ DBG((dbgphi, 1, "\n"));
return pu;
}
-
+/**
+ * Deletes a phi unit
+ */
static void free_phi_unit(phi_unit_t *pu) {
DBG((dbgphi, 1, "\n"));
- free(pu->members);
- free(pu->used_cols);
- free(pu->tgt_colors);
- free(pu->live_info);
+ if (pu->phi_count == 1) {
+ free(pu->members);
+ free(pu->colors);
+ free(pu->is_live_in);
+ } else {
+ /* TODO */
+ }
free(pu);
}
void be_phi_coalesce(pset *all_phi_classes) {
pset *pc;
- phi_unit_t *pu;
- for (pc = (pset *)pset_first(all_phi_classes); pc; pc = (pset *)pset_next(all_phi_classes)) {
- pu = new_phi_unit(pc);
- coalesce(pu);
+ pinned_nodes = pset_new_ptr(256);
+ free_nodes = pset_new_ptr(64);
+
+ for (pc = pset_first(all_phi_classes); pc; pc = pset_next(all_phi_classes)) {
+ phi_unit_t *pu = new_phi_unit(pc);
+ if (pu->phi_count == 1)
+ coalesce_1_phi(pu);
+ else
+ coalesce_n_phi(pu);
free_phi_unit(pu);
}
+
+ del_pset(free_nodes);
+ del_pset(pinned_nodes);
}
projects / libfirm / blobdiff