* @author Daniel Grund
* @date 04.01.2005
*/
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
#include <stdlib.h>
#include "irdom.h"
#include "bechordal.h"
-#include "belive.h"
+#include "belive_t.h"
#include "bera_t.h"
-#include "bephicongr_t.h"
+#include "phiclass_t.h"
#include "bephicoal_t.h"
-#define DEBUG_LVL SET_LEVEL_3
-#define MAX_COLORS 16
+#define DEBUG_LVL 0 //SET_LEVEL_2
+#define MAX_COLORS 32
+
+#define INITIAL_SLOTS_PINNED_GLOBAL 256
+#define INITIAL_SLOTS_CHANGED_NODES 32
/* some things for readable code */
#define CHANGE_SAVE NULL
#define CHANGE_IMPOSSIBLE (ir_node *)1
#define CHANGE_NYI (ir_node *)2
-typedef enum _perform_t { dryrun = 0, perform = 1 } perform_t;
-/* 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)
-//#define is_color_free(bl,col) (!bitset_is_set(get_ra_block_info(bl)->used_colors, col))
-
-typedef struct _phi_unit_t {
- unsigned char count;
- unsigned char phi_count;
-
- /* 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]*/
- /* TODO: perhaps unneccessary */
- char *is_live_in; /**< [i]==1 means members[i] is live-in in (all of) its cf-pred-blocks of the phi node */
-} phi_unit_t;
+#define is_conflicting_node(n) (((int)n) > 2)
+/**
+ * Models conflicts between nodes. These may be life range conflicts or
+ * pinning conflicts, which may occur while changing colors
+ */
+typedef struct _conflict_t {
+ ir_node *n1, *n2;
+} conflict_t;
-static firm_dbg_module_t *dbgphi = NULL;
-int XXX_copies=0, XXX_count=0;
+/**
+ * If an irn is changed, the changes first get stored in a node_stat_t,
+ * to allow undo of changes in case of conflicts.
+ */
+typedef struct _node_stat_t {
+ ir_node *irn;
+ int color;
+ int undo_color;
+ char status; /**< Bit 0: pinned, Bit 1: removed */
+} node_stat_t;
+#define _set_pinned(nodestat) nodestat->status |= 1
+#define _set_removed(nodestat) nodestat->status |= 2
+#define _clear_pinned(nodestat) nodestat->status &= 255 ^ 1
+#define _clear_removed(nodestat) nodestat->status &= 255 ^ 2
+#define _is_pinned(nodestat) (nodestat->status & 1)
+#define _is_removed(nodestat) (nodestat->status & 2)
/**
- * 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.
+ * Central data structure. Contains infos needed during coalescing of the
+ * corresponding phi class.
*/
-static pset *free_nodes = NULL;
+typedef struct _phi_unit_t {
+ unsigned char node_count; /**< size of the nodes-array */
+ unsigned char conflict_count; /**< size of the conflicts-array */
+ unsigned char conflict_count_org; /**< initial size of the conflicts-array */
+ ir_node **nodes; /**< [0] is the phi node. [1..node_count-1] the arguments of the phi not interfering with it */
+ conflict_t *conflicts; /**< pairs of conflicting ir_nodes. */
+ set *changed_nodes; /**< contains node_stat_t's. */
+} phi_unit_t;
+
+static firm_dbg_module_t *dbgphi = NULL;
/**
- * Contains already optimized ir_nodes of phi-classes fully processed.
+ * Contains already optimized ir_nodes of phi-units fully processed.
* So one can perform a check not to switch them twice or more.
*/
static pset *pinned_global = NULL;
+static int set_cmp_node_stat_t(const void *x, const void *y, size_t size) {
+ return ((node_stat_t *)x)->irn != ((node_stat_t *)y)->irn;
+}
+
/**
- * Contains optimized ir_nodes of the phi-classes
- * currently optimized. So one can perform a check not to switch them
- * twice or more.
+ * Finds a node status entry of a node if existent.
*/
-static pset *pinned_local = NULL;
+static INLINE node_stat_t *pu_find_node(phi_unit_t *pu, ir_node *irn) {
+ node_stat_t find;
+ find.irn = irn;
+ return set_find(pu->changed_nodes, &find, sizeof(find), HASH_PTR(irn));
+}
/**
- * Contains the hypothetic colors of currently processed phi unit
+ * Finds a node status entry of a node if existent. Otherwise it will return
+ * an initialized new entry for this node.
*/
-static set *hyp_cols = NULL;
+static INLINE node_stat_t *pu_find_or_insert_node(phi_unit_t *pu, ir_node *irn) {
+ node_stat_t find;
+ find.irn = irn;
+ find.color = NO_COLOR;
+ find.undo_color = NO_COLOR;
+ find.status = 0;
+ return set_insert(pu->changed_nodes, &find, sizeof(find), HASH_PTR(irn));
+}
-typedef struct _hyp_col_t {
- ir_node *irn;
- int color;
-} hyp_col_t;
+/**
+ * @return The virtual color of a node, if set before, else just the real color.
+ */
+static INLINE int pu_get_new_color(phi_unit_t *pu, ir_node *irn) {
+ node_stat_t *found = pu_find_node(pu, irn);
+ if (found)
+ return found->color;
+ else
+ return get_irn_color(irn);
+}
-int set_cmp_hyp_col_t(const void *x, const void *y, size_t size) {
- return ((hyp_col_t *)x)->irn != ((hyp_col_t *)y)->irn;
+/**
+ * Sets the virtual color of a node.
+ */
+static INLINE void pu_set_new_color(phi_unit_t *pu, ir_node *irn, int color) {
+ node_stat_t *found = pu_find_or_insert_node(pu, irn);
+ found->undo_color = found->color;
+ found->color = color;
+ DBG((dbgphi, LEVEL_4, "%n %d\n", irn, color));
}
+/**
+ * Sets the virtual color of a node to the color it had,
+ * before the last call to pu_set_new_color
+ */
+static INLINE void pu_undo_color(phi_unit_t *pu, ir_node *irn) {
+ node_stat_t *ns = pu_find_node(pu, irn);
+ assert(ns && "Nodes whose colors are undone must be in pu->changed_nodes");
+ ns->color = ns->undo_color;
+ DBG((dbgphi, LEVEL_3, "\t\tUndo: col(%n) := %d\n", irn, ns->undo_color));
+}
/**
- * @return The hypothetic color of the irn if available.
- * Otherwise the current color of it.
+ * Checks if a node is removed from consideration respectively building
+ * a maximum independent set.
*/
-static INLINE int get_hyp_color(ir_node *irn) {
- hyp_col_t hc;
- hyp_col_t *found;
- hc.irn = irn;
- found = set_find(hyp_cols, &hc, sizeof(hc), HASH_PTR(irn));
+static INLINE int pu_is_node_removed(phi_unit_t *pu, ir_node *irn) {
+ node_stat_t *found = pu_find_node(pu, irn);
if (found)
- return found->color;
+ return _is_removed(found);
else
- return get_irn_color(irn);
+ return 0;
+}
+
+/**
+ * Removes a node from the base set, out of which a maximum independet
+ * set gets build from.
+ */
+static INLINE void pu_remove_node(phi_unit_t *pu, ir_node *irn) {
+ node_stat_t *found = pu_find_or_insert_node(pu, irn);
+ _set_removed(found);
+ DBG((dbgphi, LEVEL_4, "%n\n", irn));
}
/**
- * Sets the hypothetic color of an irn
+ * Checks if a node is local pinned; i.e. it belongs to the same phi unit and
+ * has been optimized before the current processed one.
*/
-static INLINE void set_hyp_color(ir_node *irn, int color) {
- hyp_col_t hc;
- hyp_col_t *found;
- hc.irn = irn;
- found = set_find(hyp_cols, &hc, sizeof(hc), HASH_PTR(irn));
+static INLINE int pu_is_node_pinned(phi_unit_t *pu, ir_node *irn) {
+ node_stat_t *found = pu_find_node(pu, irn);
if (found)
- found->color = color;
- else {
- hc.color = color;
- set_insert(hyp_cols, &hc, sizeof(hc), HASH_PTR(irn));
+ return _is_pinned(found);
+ else
+ return 0;
+}
+
+/**
+ * Local-pins a node, so optimizations of further nodes of the same phi unit
+ * can handle situations in which a color change would undo prior optimizations.
+ */
+static INLINE void pu_pin_node(phi_unit_t *pu, ir_node *irn) {
+ node_stat_t *found = pu_find_or_insert_node(pu, irn);
+ _set_pinned(found);
+ DBG((dbgphi, LEVEL_4, "%n\n", irn));
+}
+
+/**
+ * If a local pinned conflict occurs, a new edge in the conflict graph is added.
+ * The next maximum independent set build, will regard it.
+ */
+static INLINE void pu_add_conflict(phi_unit_t *pu, ir_node *n1, ir_node *n2) {
+ int count = pu->conflict_count;
+
+ DBG((dbgphi, LEVEL_3, "\t %n -- %n\n", n1, n2));
+ assert(count != 255 && "Too much conflicts. Can hold max 255 entries");
+ if ((count & 15) == 0)
+ pu->conflicts = realloc(pu->conflicts, (count + 16)*sizeof(*pu->conflicts));
+
+ if ((int)n1 < (int)n2) {
+ pu->conflicts[count].n1 = n1;
+ pu->conflicts[count].n2 = n2;
+ } else {
+ pu->conflicts[count].n1 = n2;
+ pu->conflicts[count].n2 = n1;
}
+
+ pu->conflict_count++;
}
+/**
+ * Checks if two nodes are in a conflict.
+ */
+static INLINE int pu_are_conflicting(phi_unit_t *pu, ir_node *n1, ir_node *n2) {
+ const ir_node *o1, *o2;
+ int i;
+
+ if ((int)n1 < (int)n2) {
+ o1 = n1;
+ o2 = n2;
+ } else {
+ o1 = n2;
+ o2 = n1;
+ }
+ for (i = 0; i < pu->conflict_count; ++i)
+ if (pu->conflicts[i].n1 == o1 && pu->conflicts[i].n2 == o2)
+ return 1;
+ return 0;
+}
/**
- * Variable neede in _color_irn.
- * Not on stack, because never changed during recursion.
+ * Checks if a node is a member of a phi unit.
+ * Other nodes should not be pinned global.
*/
-static perform_t _color_irn_perform;
+static INLINE int pu_is_global_pinnable(phi_unit_t *pu, ir_node *irn) {
+ int i;
+ for (i = 0; i < pu->node_count; ++i)
+ if (pu->nodes[i] == irn)
+ return 1;
+ return 0;
+}
/**
- * Get all nodes which conflict with the color-setting of a node, because they
- * have the same color and are living together at some point in time.
- * @param irn The ir_node to find conflicting nodes for
- * @param color The color the conflicting nodes must have
- * @param bl The root-block of the dom-sub-tree to start the search from.
- * @param exc An exceptional node which is never added to the result set of conflicting nodes
- * @param res An obstack to grow the resulting nodes on.
+ * Determines a maximum independent set with respect to the conflict edges
+ * in pu->conflicts and the nodes beeing all non-removed nodes of pu->nodes.
+ * TODO: make this 'un-greedy'
+ * ATTENTION: be aware that phi nodes find their way into the set. For 1 phi
+ * in greedy version this is no prob, cause it comes first at [0].
*/
-static void get_conflicting_nodes(const ir_node *irn, int color, ir_node *bl, const ir_node *exc, struct obstack *res) {
- struct obstack q;
- int in, out;
-
- /* setup the queue */
- obstack_init(&q);
- obstack_ptr_grow(&q, bl);
- in = 1;
- out = 0;
-
- /* process the queue */
- while (out < in) {
- ir_node *curr_bl, *sub_bl;
- int i, max;
-
- curr_bl = ((ir_node **)obstack_base(&q))[out++];
-
- /* Add to the result all nodes in the block which live in target color
- * and interfere with the irn */
- for (i = 0, max = get_irn_n_outs(curr_bl); i < max; ++i) {
- ir_node *n = get_irn_out(curr_bl, i);
- int n_col;
- if (!is_allocatable_irn(n))
- continue;
- if (_color_irn_perform == perform)
- n_col = get_irn_color(n);
- else
- n_col = get_hyp_color(n);
+static int pu_get_mis(phi_unit_t *pu, struct obstack *res) {
+ int i, o, size = 0;
+ ir_node **mis;
- if (n != exc && get_hyp_color(n) == color && phi_ops_interfere(irn, n))
- obstack_ptr_grow(res, n);
- }
+ DBG((dbgphi, LEVEL_2, "\t Max indep set:\n"));
+ for (i = 0; i < pu->node_count; ++i) {
+ int intf_det = 0;
+ if (pu_is_node_removed(pu, pu->nodes[i]))
+ continue;
+ mis = (ir_node**) obstack_base(res);
+ for (o = 0; o < size; ++o)
+ if (pu_are_conflicting(pu, pu->nodes[i], mis[o])) {
+ intf_det = 1;
+ break;
+ }
- /* If irn lives out check i-dominated blocks where the irn lives in */
- /* Fill the queue */
- if (is_live_out(curr_bl, irn)) {
- dominates_for_each(curr_bl, sub_bl)
- if (is_live_in(sub_bl, irn)) {
- obstack_ptr_grow(&q, sub_bl);
- in++;
- }
+ if (!intf_det) {
+ DBG((dbgphi, LEVEL_2, "\t\t%n\n", pu->nodes[i]));
+ obstack_ptr_grow(res, pu->nodes[i]);
+ size++;
}
}
-
- obstack_free(&q, NULL);
+ return size;
}
-
/**
- * Tries to set the color of @p n to @p col. Performs recoloring of other nodes
- * as required to preserve correctness. Recursive.
+ * Performs virtual re-coloring of node @p n to color @p col. Virtual colors of
+ * other nodes are changed too, as required to preserve correctness. Function is
+ * aware of local and global pinning. Recursive.
* @param irn The node to set the color for
* @param col The color to set.
* @param trigger The irn that caused the wish to change the color of the irn
- * @return CHANGE_SAVE iff setting the color is possible.
+ * @param changed_nodes An obstack on which all ir_nodes get growed on, which are changed
+ * @return CHANGE_SAVE iff setting the color is possible, with all transiteve effects.
* CHANGE_IMPOSSIBLE iff conflicts with reg-constraintsis occured.
- * Else the conflicting ir_node is returned.
+ * CHANGE_NYI iff an unhandled situation occurs.
+ * Else the first conflicting ir_node encountered is returned.
*
* ASSUMPTION: Assumes that a life range of a single value can't be spilt into
* several smaller intervals where other values can live in between.
+ * This should be true in SSA.
*/
-static ir_node *_color_irn(ir_node *irn, int col, const ir_node *trigger) {
+static ir_node *_pu_color_irn(phi_unit_t *pu, ir_node *irn, int col, const ir_node *trigger, struct obstack *changed_nodes) {
ir_node *res;
struct obstack confl_ob;
ir_node **confl, *cn;
- ir_node *irn_bl;
int i, irn_col;
- if (_color_irn_perform == perform)
- irn_col = get_irn_color(irn);
- else
- irn_col = get_hyp_color(irn);
+ DBG((dbgphi, LEVEL_3, "\t\t%n \tcaused col(%n) \t%2d --> %2d\n", trigger, irn, pu_get_new_color(pu, irn), col));
obstack_init(&confl_ob);
+ irn_col = pu_get_new_color(pu, irn);
if (irn_col == col)
goto ret_save;
-
- if (pset_find_ptr(pinned_global, irn)) {
- DBG((dbgphi, LEVEL_3, "\t\t\t%n \t~~> %n := %d: Pinned other\n", trigger, irn, col));
+ if (pset_find_ptr(pinned_global, irn) || pu_is_node_pinned(pu, irn)) {
res = irn;
goto ret_confl;
}
- if (pset_find_ptr(pinned_local, irn)) {
- DBG((dbgphi, LEVEL_3, "\t\t\t%n \t~~> %n := %d: Pinned current\n", trigger, irn, col));
- res = irn;
- goto ret_confl;
+ /* get all nodes which would conflict with this change */
+ {
+ struct obstack q;
+ int in, out;
+ ir_node *irn_bl;
+
+ irn_bl = get_nodes_block(irn);
+
+ /* first check for a conflicting node which is 'living in' the irns block */
+ {
+ ir_node *n;
+ pset *live_ins = get_live_in(irn_bl);
+ for (n = pset_first(live_ins); n; n = pset_next(live_ins))
+ if (is_allocatable_irn(n) && n != trigger && pu_get_new_color(pu, n) == col && phi_ops_interfere(irn, n)) {
+ DBG((dbgphi, LEVEL_4, "\t\t %n\ttroubles\n", n));
+ obstack_ptr_grow(&confl_ob, n);
+ pset_break(live_ins);
+ break;
+ }
+ }
+
+ /* setup the queue of blocks. */
+ obstack_init(&q);
+ obstack_ptr_grow(&q, irn_bl);
+ in = 1;
+ out = 0;
+
+ /* process the queue. The code below checks for every block dominated
+ * by the irns one, and in which the irn is live, if there are
+ * conflicting nodes */
+ while (out < in) {
+ ir_node *curr_bl, *sub_bl;
+ int i, max;
+
+ curr_bl = ((ir_node **)obstack_base(&q))[out++];
+
+ /* Add to the result all nodes in the block, which have
+ * the target color and interfere with the irn */
+ for (i = 0, max = get_irn_n_outs(curr_bl); i < max; ++i) {
+ ir_node *n = get_irn_out(curr_bl, i);
+ if (is_allocatable_irn(n) && n != trigger && pu_get_new_color(pu, n) == col && phi_ops_interfere(irn, n)) {
+ DBG((dbgphi, LEVEL_4, "\t\t %n\ttroubles\n", n));
+ obstack_ptr_grow(&confl_ob, n);
+ }
+ }
+
+ /* If irn lives out check i-dominated blocks where the irn lives in */
+ /* Fill the queue */
+ if (is_live_out(curr_bl, irn)) {
+ dominates_for_each(curr_bl, sub_bl)
+ if (is_live_in(sub_bl, irn)) {
+ obstack_ptr_grow(&q, sub_bl);
+ in++;
+ }
+ }
+ }
+ obstack_free(&q, NULL);
+ obstack_ptr_grow(&confl_ob, NULL);
+ confl = (ir_node **) obstack_finish(&confl_ob);
}
/* process all nodes which would conflict with this change */
- irn_bl = get_nodes_block(irn);
- get_conflicting_nodes(irn, col, irn_bl, trigger, &confl_ob);
- obstack_ptr_grow(&confl_ob, NULL);
- confl = (ir_node **) obstack_finish(&confl_ob);
-
for (i = 0, cn = confl[0]; cn; cn = confl[++i]) {
ir_node *sub_res;
- /* for now don't let the changes spread in root-direction of the dom-tree */
- if (is_live_in(irn_bl, cn)) {
- DBG((dbgphi, LEVEL_3, "\t\t\t%n \t~~> %n := %d: NYI %n\n", trigger, irn, col, cn));
- res = CHANGE_NYI;
- goto ret_confl;
- }
-
/* try to color the conflicting node cn with the color of the irn itself */
- DBG((dbgphi, LEVEL_3, "\t\t\t%n \t~~> %n := %d: Subcheck\n", trigger, irn, col));
- sub_res = _color_irn(cn, irn_col, irn);
+ sub_res = _pu_color_irn(pu, cn, irn_col, irn, changed_nodes);
if (sub_res != CHANGE_SAVE) {
res = sub_res;
goto ret_confl;
}
}
- /* if we arrive here all sub changes can be applied,
- * so it is save to change this irn */
+ /* if we arrive here all sub changes can be applied, so it's save to change this irn */
ret_save:
- DBG((dbgphi, LEVEL_2, "\t\t\t%n \t~~> %n := %d: Save\n", trigger, irn, col));
+ DBG((dbgphi, LEVEL_3, "\t\t%n save\n", irn));
obstack_free(&confl_ob, NULL);
- if (_color_irn_perform == perform)
- set_irn_color(irn, col);
- else
- set_hyp_color(irn, col);
+ pu_set_new_color(pu, irn, col);
+ obstack_ptr_grow(changed_nodes, irn);
return CHANGE_SAVE;
ret_confl:
- DBG((dbgphi, LEVEL_2, "\t\t\t%n \t~~> %n := %d: Conflict\n", trigger, irn, col));
+ DBG((dbgphi, LEVEL_3, "\t\t%n conflicting\n", irn));
obstack_free(&confl_ob, NULL);
- assert(!_color_irn_perform && "When applying changes these must be save, but if you reach here they aren't!");
return res;
}
-
-static ir_node *color_irn(ir_node *irn, int col, perform_t do_what) {
+static ir_node *pu_color_irn(phi_unit_t *pu, ir_node *irn, int col) {
ir_node *res;
+ struct obstack ob_undo;
- _color_irn_perform = do_what;
- res = _color_irn(irn, col, irn);
+ obstack_init(&ob_undo);
+ res = _pu_color_irn(pu, irn, col, irn, &ob_undo);
- if (res == CHANGE_SAVE && !pset_find_ptr(free_nodes, irn)) {
- if (do_what == perform) {
- DBG((dbgphi, LEVEL_2, "\t\t\t\t\t @G %n\n", irn));
- pset_insert_ptr(pinned_global, irn);
- } else {
- DBG((dbgphi, LEVEL_2, "\t\t\t\t\t @L %n\n", irn));
- pset_insert_ptr(pinned_local, irn);
- }
+ if (res != CHANGE_SAVE) { /* undo virtual changes caused by the last call */
+ int i;
+ ir_node *undo_node, **undo_nodes;
+
+ obstack_ptr_grow(&ob_undo, NULL);
+ undo_nodes = obstack_finish(&ob_undo);
+ for (i = 0, undo_node = undo_nodes[0]; undo_node; undo_node = undo_nodes[++i])
+ pu_undo_color(pu, undo_node);
}
+
+ obstack_free(&ob_undo, NULL);
return res;
}
-
/**
* Tries to set as much members of a phi unit as possible to color @p col.
- * - Each change taken alone is guaranteed to be conflict free.
- * - _If_ all members are neither live-in nor live-out in their cf-pred-blocks
- * _then_ all changes together can be applied conflict free.
- * - _If_ there is a member, which is live-in or live-out in its cf-pred-block
- * of the phi node, it is possible that all changes together will conflict.
- * TODO: Check above comment with swapping complete colors in mind
- * TODO: Write sth. about dom-tree influence on this.
+ * All changes taken together are guaranteed to be conflict free.
*/
-static int try_colors(phi_unit_t *pu, int col, int b_size) {
- struct obstack ob;
- int i, o, cand_size, mis_size;
- ir_node **cand, **mis;
-
- obstack_init(&ob);
- pinned_local = pset_new_ptr(8);
- hyp_cols = new_set(set_cmp_hyp_col_t, 8);
-
- /* first init pessimistically, so we can just return
- * if we see there wont be a better result */
- mis_size = 0;
- for (i = 0; i < pu->count; ++i)
- pu->colors[i] = NO_COLOR;
-
- /* For all members check if color would be possible.
- * Does not check if color is possible in combination with
- * other members colors being set */
- cand_size = 0;
- for (i = 0; i < pu->count; ++i) {
- DBG((dbgphi, 1, "\t\t Testing %n\n", pu->members[i]));
- if (color_irn(pu->members[i], col, dryrun) == CHANGE_SAVE) {
- DBG((dbgphi, 1, "\t\t\tAdding to cand\n"));
- obstack_ptr_grow(&ob, pu->members[i]);
- cand_size++;
- } else {
- DBG((dbgphi, 1, "\t\t\tImpossible\n"));
- }
- /* if color is not possible for the phi node then exit (phi comes first)*/
- if (cand_size == 0)
+static int pu_try_color(phi_unit_t *pu, int col, int b_size) {
+ struct obstack ob_mis;
+ int i, redo, mis_size;
+ ir_node **mis;
+
+ obstack_init(&ob_mis);
+ redo = 1;
+ while (redo) {
+ redo = 0;
+ /* get a max independent set regarding current conflicts */
+ mis_size = pu_get_mis(pu, &ob_mis);
+ mis = obstack_finish(&ob_mis);
+
+ /* shortcut: if mis size is worse than best, then mis won't be better. */
+ if (mis_size < b_size)
goto ret;
- }
- cand = obstack_finish(&ob);
- /* shortcut: if cand is worse than best then mis wont be better. */
- if (cand_size < b_size)
- goto ret;
+ /* check if its possible to set the color for all members of the maximum set*/
+ for (i = 0; i < mis_size; ++i) {
+ ir_node *test_node, *confl_node;
+
+ test_node = mis[i];
+ DBG((dbgphi, LEVEL_2, "\t Testing %n\n", test_node));
+ confl_node = pu_color_irn(pu, test_node, col);
+
+ if (confl_node == CHANGE_SAVE) {
+ DBG((dbgphi, LEVEL_2, "\t Save\n"));
+ pu_pin_node(pu, test_node);
+ } else if (confl_node == CHANGE_NYI) {
+ DBG((dbgphi, 0, "\t NYI\n"));
+ } else if (confl_node == CHANGE_IMPOSSIBLE) {
+ /* TODO: this may happen due to reg constraints --> remove from set ?? */
+ } else {
+ DBG((dbgphi, LEVEL_2, "\t Conflicting\n"));
+ assert(is_conflicting_node(confl_node));
- /* now take the candidates cand and determine a max independent set
- * with respect to edges representing live range interference */
- /* TODO: make this 'un-greedy' */
- DBG((dbgphi, 1, "\t\t Max indep set\n"));
- 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 (phi_ops_interfere(cand[i], mis[o])) {
- intf_det = 1;
- break;
+ if (pu_is_node_pinned(pu, confl_node)) {
+ /* changing test_node would change back a node of current phi unit */
+ pu_add_conflict(pu, confl_node, test_node);
+ redo = 1;
+ }
+ if (pset_find_ptr(pinned_global, confl_node)) {
+ /* changing test_node would change back a node of a prior phi unit */
+ pu_remove_node(pu, test_node);
+ redo = 1;
+ }
}
- }
- if (!intf_det) {
- DBG((dbgphi, 1, "\t\t\tAdding to mis %n\n", cand[i]));
- obstack_ptr_grow(&ob, cand[i]);
- mis_size++;
+ if (confl_node != CHANGE_SAVE) {
+ /* shortcut: color not possible for phi node (phi comes first) ==> exit */
+ if (i == 0) {
+ mis_size = 0;
+ goto ret;
+ }
+ /* break iteration over current mis, because it will change */
+ break;
+ }
}
+ obstack_free(&ob_mis, mis);
}
- mis = obstack_finish(&ob);
-
- /* Now set the colors of all nodes in the mis to col.
- * HINT: Set the color of all nodes, even if one has the same color already */
- for (i = 0; i < pu->count; ++i)
- for (o = 0; o < mis_size; ++o)
- if (pu->members[i] == mis[o])
- pu->colors[i] = col;
ret:
- del_set(hyp_cols);
- del_pset(pinned_local);
- obstack_free(&ob, NULL);
+ obstack_free(&ob_mis, NULL);
return mis_size;
}
-
-/**
- * Sets the colors of members[i] to colors[i].
- * All changes togehter must be conflict free.
- */
-static void set_colors(phi_unit_t *pu) {
- int i;
-
- for (i = 0; i < pu->count; ++i)
- if (pu->colors[i] != NO_COLOR)
- color_irn(pu->members[i], pu->colors[i], perform);
-}
-
-
/**
- * 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% of all phi classes.
+ * Tries to re-allocate colors of nodes in this phi unit, to achieve a lower
+ * number of copy instructions placed during phi destruction. Optimized version.
+ * Works only for phi-classes/phi-units with exactly 1 phi node, which is the
+ * case for approximately 80% of all phi classes. All other phi classes are
+ * reduced to this case.
*/
-static void coalesce_1_phi(phi_unit_t *pu) {
- int *b_colors, b_size, b_color;
- int i, size, col;
-
- b_colors = malloc(pu->count * sizeof(*b_colors));
+static void pu_coal_1_phi(phi_unit_t *pu) {
+ int size, col, b_size, b_color;
+ set *b_changes;
/* init best search result */
+ b_changes = NULL;
b_size = 0;
b_color = NO_COLOR;
- for (i = 0; i < pu->count; ++i)
- b_colors[i] = NO_COLOR;
/* find optimum of all colors */
for (col = MAX_COLORS-1; col >= 0; --col) {
DBG((dbgphi, 1, "\tTrying color %d\n", col));
- size = try_colors(pu, col, b_size);
+ size = pu_try_color(pu, col, b_size);
/* did we find a better max ind. set? */
if (size > b_size) {
+ DBG((dbgphi, 1, "\tBetter size: %d\n", size));
+ if (b_changes)
+ del_set(b_changes);
+ b_changes = pu->changed_nodes;
b_size = size;
b_color = col;
- memcpy(b_colors, pu->colors, pu->count * sizeof(*b_colors));
- DBG((dbgphi, 1, "\t!! Better size: %d\n", b_size));
+ } else {
+ del_set(pu->changed_nodes);
}
- /* shortcut: if all members can be colored we are content */
- if (b_size == pu->count)
+ /* reset the phi unit to original state for next color */
+ pu->changed_nodes = new_set(set_cmp_node_stat_t, INITIAL_SLOTS_CHANGED_NODES);
+ pu->conflict_count = pu->conflict_count_org;
+
+ /* shortcut: if all members can be colored we are (very) happy */
+ if (b_size == pu->node_count)
break;
}
- DBG((dbgphi, 1, "\tBest color: %d Copies: %d/%d\n", b_color, pu->count-b_size, pu->count));
- XXX_copies += pu->count-b_size;
- XXX_count += pu->count;
- if (b_color == NO_COLOR)
- goto ret;
/* now apply the found optimum */
- memcpy(pu->colors, b_colors, pu->count * sizeof(*b_colors));
- set_colors(pu);
-
-ret:
- 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 */
+ if (b_changes) {
+ node_stat_t *ns;
+ DBG((dbgphi, 1, "\tBest color: %d Copies: %d/%d\n", b_color, pu->node_count-b_size, pu->node_count-1));
+ for (ns = set_first(b_changes); ns; ns = set_next(b_changes)) {
+ /* NO_COLOR is possible, if we had an undo; so the irn stays in the
+ * pu->changed_nodes with new color set to NO_COLOR. */
+ if (ns->color != NO_COLOR) {
+ DBG((dbgphi, 1, "\t color(%n) := %d\n", ns->irn, ns->color));
+ set_irn_color(ns->irn, ns->color);
+ if (pu_is_global_pinnable(pu, ns->irn) && ns->color == pu_get_new_color(pu, pu->nodes[0]))
+ pset_insert_ptr(pinned_global, ns->irn);
+ }
+ }
+ free(b_changes);
+ } else {
+ DBG((dbgphi, 1, "\tBest color: none\n"));
+ }
}
/**
- * Prepares a phi class for further processing as a phi unit.
- * @param pc The phi class to prepare.
- * @return A so called phi unit containing some prepared informations
- * needed by the following coalescing phase.
+ * Prepares a phi class for further processing as one or more phi units.
+ * Calls the worker-functions for all units.
+ * @param pc The phi class to process.
+ * @param root_phi In case of recursive call this is the phi node not beeing
+ * an argument in the phi1unit.
+ * Else this has to be NULL.
*/
-static phi_unit_t *new_phi_unit(pset *pc) {
- phi_unit_t *pu;
+static void coal_phi_class(pset *pc, ir_node *root_phi) {
+ int phi_count = 0;
ir_node *n, *phi = NULL;
- /* get the phi count of this class */
- 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++;
- }
+ /* unfortunately there _can_ be >1 phi nodes in a phi1unit,
+ * so we have an if... */
+ if (root_phi) {
+ phi = root_phi;
+ phi_count = 1;
+ } else {
+ /* get the phi count of this class. May result in phi_count == 1 */
+ for (n = pset_first(pc); n; n = pset_next(pc))
+ if (is_Phi(n)) {
+ phi = n;
+ phi_count++;
+ }
+ }
- if (pu->phi_count == 1) {
- ir_node **tmp, *phi_block;
- int i, max;
+ /* the 'simple' case */
+ if (phi_count == 1) {
+ phi_unit_t *pu;
+ ir_node **tmp;
struct obstack ob;
+ int i, o;
obstack_init(&ob);
+ DBG((dbgphi, 1, "\tPhi-1 unit:\n"));
+ pu = calloc(1, sizeof(*pu));
+
/* build member set not containing phi interferers */
- DBG((dbgphi, 1, "Phi-1 class:\n"));
- pu->count = 1; /*for the phi*/
+ DBG((dbgphi, 1, "\t %n\n", phi));
+ obstack_ptr_grow(&ob, phi);
+ pu->node_count = 1;
+
for (n = pset_first(pc); n; n = pset_next(pc)) {
- if (is_Phi(n))
+ if (n == phi)
continue;
if (!phi_ops_interfere(phi, n)) {
- DBG((dbgphi, 1, "\tAdding to members: %n\n", n));
+ DBG((dbgphi, 1, "\t %n\n", n));
obstack_ptr_grow(&ob, n);
- pu->count++;
+ pu->node_count++;
} else {
- DBG((dbgphi, 1, "\tPhi interferer: %n\n", n));
- pset_insert_ptr(free_nodes, n);
+ DBG((dbgphi, 1, "\t %n \tdropped\n", 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;
+ pu->nodes = malloc(pu->node_count * sizeof(*pu->nodes));
+ memcpy(&pu->nodes[0], tmp, pu->node_count * sizeof(*tmp));
+ obstack_free(&ob, NULL);
- 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));
- }
+ /* init conlict graph to life range interference */
+ DBG((dbgphi, 1, "\tInitial conflicts:\n"));
+ for (i = 0; i < pu->node_count; ++i)
+ for (o = i+1; o < pu->node_count; ++o)
+ if (phi_ops_interfere(pu->nodes[i], pu->nodes[o]))
+ pu_add_conflict(pu, pu->nodes[i], pu->nodes[o]);
+ pu->conflict_count_org = pu->conflict_count;
+
+ /* init changed nodes */
+ pu->changed_nodes = new_set(set_cmp_node_stat_t, INITIAL_SLOTS_CHANGED_NODES);
+
+ pu_coal_1_phi(pu);
+
+ free(pu->nodes);
+ free(pu->changed_nodes);
+ if (pu->conflicts)
+ free(pu->conflicts);
+ } else { /* the 'not so easy' case */
+ DBG((dbgphi, 1, "\tPhi-n unit:\n"));
+
+ /* copy pc into big_pc... */
+ pset *copy = pset_new_ptr(32);
+ for (n = pset_first(pc); n; n = pset_next(pc)) {
+ DBG((dbgphi, 1, "\t %n\n", n));
+ pset_insert_ptr(copy, n);
}
- obstack_free(&ob, NULL);
- } else {
- DBG((dbgphi, 1, "Phi-n class:\n"));
- /* TODO */
- }
+ /* ... because we want to build small 'connected graphs' and
+ * delete their members from the copy */
+ while (pset_count(copy) > 0) {
+ /* build all connected sets from the copy */
+ int last = 0, first = 0;
+ ir_node **queue = calloc(pset_count(copy), sizeof(*queue));
+
+ /* pick some node out of copy, place into queue */
+ n = pset_first(copy);
+ pset_break(copy);
+ pset_remove_ptr(copy, n);
+ queue[last++] = n;
+
+ DBG((dbgphi, 1, "\tConnected:\n"));
+ pset *connected = pset_new_ptr(8);
+ while (first < last) {
+ /* pick n out of the queue into connected set */
+ n = queue[first++];
+ pset_insert_ptr(connected, n);
+ DBG((dbgphi, 1, "\t %n\n", n));
+
+
+ /* check if pre/successors are 'connected' with n */
+ {
+ ir_node *other;
+ int i;
+ /* insert all args of n, which are in the phi class to the queue */
+ for(i=0; i < get_irn_arity(n); ++i) {
+ other = get_irn_n(n, i);
+ if (pset_find_ptr(copy, other) && !values_interfere(n, other)) {
+ queue[last++] = other;
+ pset_remove_ptr(copy, other);
+ }
+ }
+ /* same for outs of n */
+ for(i=0; i < get_irn_n_outs(n); ++i) {
+ other = get_irn_out(n, i);
+ if (pset_find_ptr(copy, other) && !values_interfere(n, other)) {
+ queue[last++] = other;
+ pset_remove_ptr(copy, other);
+ }
+ }
+ }
+ }
- DBG((dbgphi, 1, "\n"));
- return pu;
-}
+ /* Now we have a "connected graph" build from copy==pc.
+ * Remove 1-phi-units from the connected set for
+ * passing to optimizer */
+ while (pset_count(connected) > 0) {
+ pset *phi1unit;
+ ir_node *phi = NULL;
+ int i;
+ /* search a phi node */
+ for (n = pset_first(connected); n; n = pset_next(connected))
+ if (is_Phi(n)) {
+ phi = n;
+ break;
+ }
+ pset_break(connected);
+
+ /* if there are only non-phi nodes left quit */
+ if (!phi)
+ break;
+ /* Build a 1-phi-unit with this phi */
+ DBG((dbgphi, 1, "\t Phi-1-unit:\n"));
+ phi1unit = pset_new_ptr(8);
+ pset_insert_ptr(phi1unit, phi);
+ pset_remove_ptr(connected, phi);
+ DBG((dbgphi, 1, "\t\t%n\n", phi));
+ /* insert all arguments of phi, which are in the connected set
+ * to the 1-phi-unit */
+ for(i=0; i < get_irn_arity(phi); ++i) {
+ ir_node *arg = get_irn_n(phi, i);
+ if (pset_find_ptr(connected, arg)) {
+ DBG((dbgphi, 1, "\t\t%n\n", arg));
+ pset_insert_ptr(phi1unit, arg);
+ pset_remove_ptr(connected, arg);
+ }
+ }
-/**
- * Deletes a phi unit
- */
-static void free_phi_unit(phi_unit_t *pu) {
- if (pu->phi_count == 1) {
- free(pu->members);
- free(pu->colors);
- free(pu->is_live_in);
- } else {
- /* TODO */
+ /* finally the call for coalescing the 1-phi-unit */
+ if (pset_count(phi1unit) > 1) /* ==1 can happen if the connected set contains only a single phi node */
+ coal_phi_class(phi1unit, phi);
+
+ del_pset(phi1unit);
+ }
+ del_pset(connected);
+ free(queue);
+ }
+ del_pset(copy);
}
- free(pu);
}
void be_phi_coalesce(pset *all_phi_classes) {
pset *pc;
- pinned_global = 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);
- }
+ pinned_global = pset_new_ptr(INITIAL_SLOTS_PINNED_GLOBAL);
- DBG((dbgphi, 1, "Copies: %d / %d\n", XXX_copies, XXX_count));
+ for (pc = pset_first(all_phi_classes); pc; pc = pset_next(all_phi_classes))
+ coal_phi_class(pc, NULL);
- del_pset(free_nodes);
del_pset(pinned_global);
}
void be_phi_coal_init(void) {
- dbgphi = firm_dbg_register("Phi coalescing");
+ dbgphi = firm_dbg_register("ir.be.phicoal");
firm_dbg_set_mask(dbgphi, DEBUG_LVL);
}