* Copyright: (c) Universitaet Karlsruhe
* Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
*/
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <stdlib.h>
#include "pset.h"
#include "irnode_t.h"
#include "ircons_t.h"
#include "iredges_t.h"
+#include "ident_t.h"
+#include "type_t.h"
+#include "entity_t.h"
#include "debug.h"
+#include "irgwalk.h"
+#include "array.h"
+#include "pdeq.h"
-#include "besched.h"
+#include "belive_t.h"
+#include "besched_t.h"
#include "bespill.h"
#include "benode_t.h"
+#include "bechordal_t.h"
+
+/* This enables re-computation of values. Current state: Unfinished and buggy. */
+#undef BUGGY_REMAT
typedef struct _reloader_t reloader_t;
typedef struct _spill_info_t spill_info_t;
} spill_ctx_t;
struct _spill_env_t {
- firm_dbg_module_t *dbg;
const arch_register_class_t *cls;
- const be_main_session_env_t *session;
+ const be_chordal_env_t *chordal_env;
struct obstack obst;
set *spill_ctxs;
set *spills; /**< all spill_info_t's, which must be placed */
- pset *mem_phis; /**< set of all special spilled phis. allocated and freed seperately */
- decide_irn_t is_mem_phi; /**< callback func to decide if a phi needs special spilling */
- void *data; /**< data passed to all callbacks */
+ pset *mem_phis; /**< set of all special spilled phis. allocated and freed separately */
+ ir_node **copies; /**< set of copies placed because of phi spills */
+ DEBUG_ONLY(firm_dbg_module_t *dbg;)
};
+/* associated Phi -> Spill*/
+typedef struct _phi_spill_assoc_t {
+ ir_node *phi;
+ ir_node *spill;
+} phi_spill_assoc_t;
+
+/**
+ * Compare two Phi->Spill associations.
+ */
+static int cmp_phi_spill_assoc(const void *a, const void *b, size_t n) {
+ const phi_spill_assoc_t *p1 = a;
+ const phi_spill_assoc_t *p2 = b;
+ return p1->phi != p2->phi;
+}
+
+/**
+ * compare two spill contexts.
+ */
static int cmp_spillctx(const void *a, const void *b, size_t n) {
const spill_ctx_t *p = a;
const spill_ctx_t *q = b;
- return !(p->user == q->user && p->spilled == q->spilled);
+ return p->user != q->user || p->spilled != q->spilled;
}
+/**
+ * Compare two spill infos.
+ */
static int cmp_spillinfo(const void *x, const void *y, size_t size) {
const spill_info_t *xx = x;
const spill_info_t *yy = y;
- return ! (xx->spilled_node == yy->spilled_node);
+ return xx->spilled_node != yy->spilled_node;
}
-spill_env_t *be_new_spill_env(firm_dbg_module_t *dbg, const be_main_session_env_t *session,
- const arch_register_class_t *cls, decide_irn_t is_mem_phi, void *data) {
- spill_env_t *env = malloc(sizeof(env[0]));
- env->spill_ctxs = new_set(cmp_spillctx, 1024);
- env->spills = new_set(cmp_spillinfo, 1024);
- env->session = session;
- env->cls = cls;
- env->dbg = dbg;
- env->is_mem_phi = is_mem_phi;
- env->data = data;
+DEBUG_ONLY(
+/* Sets the debug module of a spill environment. */
+void be_set_spill_env_dbg_module(spill_env_t *env, firm_dbg_module_t *dbg) {
+ env->dbg = dbg;
+}
+)
+
+/* Creates a new spill environment. */
+spill_env_t *be_new_spill_env(const be_chordal_env_t *chordal_env) {
+ spill_env_t *env = xmalloc(sizeof(env[0]));
+ env->spill_ctxs = new_set(cmp_spillctx, 1024);
+ env->spills = new_set(cmp_spillinfo, 1024);
+ env->cls = chordal_env->cls;
+ env->chordal_env = chordal_env;
+ env->mem_phis = pset_new_ptr_default();
+ env->copies = NEW_ARR_F(ir_node*, 0);
obstack_init(&env->obst);
return env;
}
-void be_delete_spill_env(spill_env_t *senv) {
- del_set(senv->spill_ctxs);
- del_set(senv->spills);
- obstack_free(&senv->obst, NULL);
- free(senv);
+/* Deletes a spill environment. */
+void be_delete_spill_env(spill_env_t *env) {
+ del_set(env->spill_ctxs);
+ del_set(env->spills);
+ del_pset(env->mem_phis);
+ DEL_ARR_F(env->copies);
+ obstack_free(&env->obst, NULL);
+ free(env);
}
+/**
+ * Returns a spill context. If the context did not exists, create one.
+ *
+ * @param sc the set containing all spill contexts
+ * @param to_spill the node that should be spilled
+ * @param ctx_irn an user of the spilled node
+ *
+ * @return a spill context.
+ */
static spill_ctx_t *be_get_spill_ctx(set *sc, ir_node *to_spill, ir_node *ctx_irn) {
spill_ctx_t templ;
return set_insert(sc, &templ, sizeof(templ), HASH_COMBINE(HASH_PTR(to_spill), HASH_PTR(ctx_irn)));
}
+/**
+ * Schedules a node after an instruction. (That is the place after all projs and phis
+ * that are scheduled after the instruction)
+ */
+static void sched_add_after_insn(ir_node *sched_after, ir_node *node) {
+ ir_node *next = sched_next(sched_after);
+ while(!sched_is_end(next)) {
+ if(!is_Proj(next) && !is_Phi(next))
+ break;
+ next = sched_next(next);
+ }
+
+ if(sched_is_end(next)) {
+ next = sched_last(get_nodes_block(sched_after));
+ sched_add_after(next, node);
+ } else {
+ sched_add_before(next, node);
+ }
+}
+
+/**
+ * Creates a spill.
+ *
+ * @param senv the spill environment
+ * @param irn the node that should be spilled
+ * @param ctx_irn an user of the spilled node
+ *
+ * @return a be_Spill node
+ */
static ir_node *be_spill_irn(spill_env_t *senv, ir_node *irn, ir_node *ctx_irn) {
spill_ctx_t *ctx;
- DBG((senv->dbg, LEVEL_1, "%+F\n", irn));
+ const be_main_env_t *env = senv->chordal_env->birg->main_env;
+ DBG((senv->dbg, LEVEL_1, "%+F in ctx %+F\n", irn, ctx_irn));
+ // Has the value already been spilled?
ctx = be_get_spill_ctx(senv->spill_ctxs, irn, ctx_irn);
- if(!ctx->spill) {
- const be_main_env_t *env = senv->session->main_env;
- ctx->spill = be_spill(env->node_factory, env->arch_env, irn);
+ if(ctx->spill)
+ return ctx->spill;
+
+ /* Trying to spill an already spilled value, no need for a new spill
+ * node then, we can simply connect to the same one for this reload
+ */
+ if(be_is_Reload(irn)) {
+ return get_irn_n(irn, be_pos_Reload_mem);
}
+ ctx->spill = be_spill(env->arch_env, irn, ctx_irn);
+ sched_add_after_insn(irn, ctx->spill);
+
return ctx->spill;
}
/**
- * If the first usage of a phi result would be out of memory
+ * Removes all copies introduced for phi-spills
+ */
+static void remove_copies(spill_env_t *env) {
+ int i;
+
+ for(i = 0; i < ARR_LEN(env->copies); ++i) {
+ ir_node *node = env->copies[i];
+ ir_node *src;
+ const ir_edge_t *edge, *ne;
+
+ assert(be_is_Copy(node));
+
+ src = be_get_Copy_op(node);
+ foreach_out_edge_safe(node, edge, ne) {
+ ir_node *user = get_edge_src_irn(edge);
+ int user_pos = get_edge_src_pos(edge);
+
+ set_irn_n(user, user_pos, src);
+ }
+ }
+
+ ARR_SETLEN(ir_node*, env->copies, 0);
+}
+
+static INLINE ir_node *skip_projs(ir_node *node) {
+ while(is_Proj(node)) {
+ node = sched_next(node);
+ assert(!sched_is_end(node));
+ }
+
+ return node;
+}
+
+/**
+ * Searchs the schedule backwards until we reach the first use or def of a
+ * value or a phi.
+ * Returns the node after this node (so that you can do sched_add_before)
+ */
+static ir_node *find_last_use_def(spill_env_t *env, ir_node *block, ir_node *value) {
+ ir_node *node, *last;
+
+ last = NULL;
+ sched_foreach_reverse(block, node) {
+ int i, arity;
+
+ if(is_Phi(node)) {
+ return last;
+ }
+ if(value == node) {
+ return skip_projs(last);
+ }
+ for(i = 0, arity = get_irn_arity(node); i < arity; ++i) {
+ ir_node *arg = get_irn_n(node, i);
+ if(arg == value) {
+ return skip_projs(last);
+ }
+ }
+ last = node;
+ }
+
+ // simply return first node if no def or use found
+ return sched_first(block);
+}
+
+/**
+ * If the first usage of a Phi result would be out of memory
* there is no sense in allocating a register for it.
* Thus we spill it and all its operands to the same spill slot.
* Therefore the phi/dataB becomes a phi/Memory
+ *
+ * @param senv the spill environment
+ * @param phi the Phi node that should be spilled
+ * @param ctx_irn an user of the spilled node
+ *
+ * @return a be_Spill node
*/
-static ir_node *be_spill_phi(spill_env_t *senv, ir_node *phi, ir_node *ctx_irn) {
- int i, n = get_irn_arity(phi);
- ir_node **ins, *bl = get_nodes_block(phi);
- ir_graph *irg = senv->session->irg;
+static ir_node *spill_phi(spill_env_t *senv, ir_node *phi, ir_node *ctx_irn, set *already_visited_phis, bitset_t *bs) {
+ int i;
+ int arity = get_irn_arity(phi);
+ ir_graph *irg = senv->chordal_env->irg;
+ ir_node *bl = get_nodes_block(phi);
+ ir_node **ins, *phi_spill;
+ phi_spill_assoc_t key;
spill_ctx_t *ctx;
assert(is_Phi(phi));
- DBG((senv->dbg, LEVEL_1, "%+F\n", phi));
+ DBG((senv->dbg, LEVEL_1, "%+F in ctx %+F\n", phi, ctx_irn));
+
+ /* build a new PhiM */
+ NEW_ARR_A(ir_node *, ins, arity);
+ for (i = 0; i < arity; ++i) {
+ ins[i] = new_r_Bad(irg);
+ }
+ phi_spill = new_r_Phi(senv->chordal_env->irg, bl, arity, ins, mode_M);
+ key.phi = phi;
+ key.spill = phi_spill;
+ set_insert(already_visited_phis, &key, sizeof(key), HASH_PTR(phi));
+ bitset_set(bs, get_irn_idx(phi));
/* search an existing spill for this context */
ctx = be_get_spill_ctx(senv->spill_ctxs, phi, ctx_irn);
/* if not found spill the phi */
- if(!ctx->spill) {
- /* build a new PhiM with dummy in-array */
- ins = malloc(n * sizeof(ins[0]));
- for(i=0; i<n; ++i)
- ins[i] = new_r_Unknown(irg, mode_M);
- ctx->spill = new_r_Phi(senv->session->irg, bl, n, ins, mode_M);
- free(ins);
-
- /* re-wire the phiM */
- for(i=0; i<n; ++i) {
+ if (! ctx->spill) {
+ /* collect all arguments of the phi */
+ for (i = 0; i < arity; ++i) {
ir_node *arg = get_irn_n(phi, i);
ir_node *sub_res;
-
- if(is_Phi(arg) && pset_find_ptr(senv->mem_phis, arg))
- sub_res = be_spill_phi(senv, arg, ctx_irn);
- else
+ phi_spill_assoc_t *entry;
+
+ if(is_Phi(arg) && pset_find_ptr(senv->mem_phis, arg)) {
+ // looping edge?
+ if(arg == phi) {
+ sub_res = phi_spill;
+ } else if (! bitset_is_set(bs, get_irn_idx(arg))) {
+ sub_res = spill_phi(senv, arg, ctx_irn, already_visited_phis, bs);
+ } else {
+ /* we already visited the argument phi: get it's spill */
+ key.phi = arg;
+ key.spill = NULL;
+ entry = set_find(already_visited_phis, &key, sizeof(key), HASH_PTR(arg));
+ assert(entry && "argument phi already visited, but no spill found?!?");
+ sub_res = entry->spill;
+ assert(sub_res && "spill missing?!?");
+ }
+ } else {
sub_res = be_spill_irn(senv, arg, ctx_irn);
+ }
- set_irn_n(ctx->spill, i, sub_res);
+ set_irn_n(phi_spill, i, sub_res);
}
+
+ ctx->spill = phi_spill;
}
return ctx->spill;
}
+/**
+ * Spill a node.
+ *
+ * @param senv the spill environment
+ * @param to_spill the node that should be spilled
+ *
+ * @return a be_Spill node
+ */
static ir_node *be_spill_node(spill_env_t *senv, ir_node *to_spill) {
- ir_node *res;
- if (pset_find_ptr(senv->mem_phis, to_spill))
- res = be_spill_phi(senv, to_spill, to_spill);
- else
+ ir_graph *irg = get_irn_irg(to_spill);
+ ir_node *res;
+
+ if (pset_find_ptr(senv->mem_phis, to_spill)) {
+ set *already_visited_phis = new_set(cmp_phi_spill_assoc, 10);
+ bitset_t *bs = bitset_alloca(get_irg_last_idx(irg));
+ res = spill_phi(senv, to_spill, to_spill, already_visited_phis, bs);
+ del_set(already_visited_phis);
+ } else {
res = be_spill_irn(senv, to_spill, to_spill);
+ }
return res;
}
-static void phi_walker(ir_node *irn, void *env) {
- spill_env_t *senv = env;
- const arch_env_t *arch = senv->session->main_env->arch_env;
+#ifdef BUGGY_REMAT
+
+/**
+ * Check if a spilled node could be rematerialized.
+ *
+ * @param senv the spill environment
+ * @param spill the Spill node
+ * @param spilled the node that was spilled
+ * @param reloader a irn that requires a reload
+ */
+static int check_remat_conditions(spill_env_t *senv, ir_node *spilled, ir_node *reloader) {
+ int pos, max;
+
+ /* check for 'normal' spill and general remat condition */
+ if (!arch_irn_is(senv->chordal_env->birg->main_env->arch_env, spilled, rematerializable))
+ return 0;
+
+ /* check availability of original arguments */
+ if (is_Block(reloader)) {
+
+ /* we want to remat at the end of a block.
+ * thus all arguments must be alive at the end of the block
+ */
+ for (pos=0, max=get_irn_arity(spilled); pos<max; ++pos) {
+ ir_node *arg = get_irn_n(spilled, pos);
+ if (!is_live_end(reloader, arg))
+ return 0;
+ }
+
+ } else {
+
+ /* we want to remat before the insn reloader
+ * thus an arguments is alive if
+ * - it interferes with the reloaders result
+ * or
+ * - or it is (last-) used by reloader itself
+ */
+ for (pos=0, max=get_irn_arity(spilled); pos<max; ++pos) {
+ ir_node *arg = get_irn_n(spilled, pos);
+ int i, m;
+
+ if (values_interfere(reloader, arg))
+ goto is_alive;
+
+ for (i=0, m=get_irn_arity(reloader); i<m; ++i) {
+ ir_node *rel_arg = get_irn_n(reloader, i);
+ if (rel_arg == arg)
+ goto is_alive;
+ }
+
+ /* arg is not alive before reloader */
+ return 0;
+
+is_alive: ;
+
+ }
- if (is_Phi(irn) && arch_irn_has_reg_class(arch, irn, 0, senv->cls)
- && senv->is_mem_phi(irn, senv->data)) {
- DBG((senv->dbg, LEVEL_1, " %+F\n", irn));
- pset_insert_ptr(senv->mem_phis, irn);
}
+
+ return 1;
}
-void be_insert_spills_reloads(spill_env_t *senv, pset *reload_set) {
- ir_graph *irg = senv->session->irg;
- ir_node *irn;
- spill_info_t *si;
- struct obstack ob;
+#else /* BUGGY_REMAT */
- obstack_init(&ob);
+/**
+ * A very simple rematerialization checker.
+ *
+ * @param senv the spill environment
+ * @param spill the Spill node
+ * @param spilled the node that was spilled
+ * @param reloader a irn that requires a reload
+ */
+static int check_remat_conditions(spill_env_t *senv, ir_node *spilled, ir_node *reloader) {
+ const arch_env_t *aenv = senv->chordal_env->birg->main_env->arch_env;
- /* get all special spilled phis */
- DBG((senv->dbg, LEVEL_1, "Mem-phis:\n"));
- senv->mem_phis = pset_new_ptr_default();
- irg_walk_graph(senv->session->irg, phi_walker, NULL, senv);
+ return get_irn_arity(spilled) == 0 &&
+ arch_irn_is(aenv, spilled, rematerializable);
+}
+
+#endif /* BUGGY_REMAT */
+
+/**
+ * Re-materialize a node.
+ *
+ * @param senv the spill environment
+ * @param spilled the node that was spilled
+ * @param reloader a irn that requires a reload
+ */
+static ir_node *do_remat(spill_env_t *senv, ir_node *spilled, ir_node *reloader) {
+ ir_node *res;
+ ir_node *bl = (is_Block(reloader)) ? reloader : get_nodes_block(reloader);
+
+ /* recompute the value */
+ res = new_ir_node(get_irn_dbg_info(spilled), senv->chordal_env->irg, bl,
+ get_irn_op(spilled),
+ get_irn_mode(spilled),
+ get_irn_arity(spilled),
+ get_irn_in(spilled) + 1);
+ copy_node_attr(spilled, res);
+
+ DBG((senv->dbg, LEVEL_1, "Insert remat %+F before reloader %+F\n", res, reloader));
+
+ /* insert in schedule */
+ if (is_Block(reloader)) {
+ ir_node *insert = sched_skip(reloader, 0, sched_skip_cf_predicator, (void *) senv->chordal_env->birg->main_env->arch_env);
+ sched_add_after(insert, res);
+ } else {
+ sched_add_before(reloader, res);
+ }
+
+ return res;
+}
- /* Add reloads for mem_phis */
- DBG((senv->dbg, LEVEL_1, "Reloads for mem-phis:\n"));
- for(irn = pset_first(senv->mem_phis); irn; irn = pset_next(senv->mem_phis)) {
+static place_copies_for_phi(spill_env_t *env, ir_node* node) {
+ int i, arity;
+
+ assert(is_Phi(node));
+
+ /* We have to place copy nodes in the predecessor blocks to temporarily
+ * produce new values that get separate spill slots
+ */
+ for(i = 0, arity = get_irn_arity(node); i < arity; ++i) {
+ ir_node *pred_block, *arg, *copy, *insert_point;
+
+ /* Don't do anything for looping edges (there's no need
+ * and placing copies here breaks stuff as it suddenly
+ * generates new living values through the whole loop)
+ */
+ arg = get_irn_n(node, i);
+ if(arg == node)
+ continue;
+
+ pred_block = get_Block_cfgpred_block(get_nodes_block(node), i);
+ copy = be_new_Copy(env->cls, get_irn_irg(arg), pred_block, arg);
+
+ ARR_APP1(ir_node*, env->copies, copy);
+ insert_point = find_last_use_def(env, pred_block, arg);
+ sched_add_before(insert_point, copy);
+
+ set_irn_n(node, i, copy);
+ }
+}
+
+void be_place_copies(spill_env_t *env) {
+ ir_node *node;
+
+ foreach_pset(env->mem_phis, node) {
+ place_copies_for_phi(env, node);
+ }
+}
+
+void be_spill_phi(spill_env_t *env, ir_node *node) {
+ spill_ctx_t *spill_ctx;
+
+ assert(is_Phi(node));
+
+ pset_insert_ptr(env->mem_phis, node);
+
+ // remove spill context for this phi (if there was one)
+ spill_ctx = be_get_spill_ctx(env->spill_ctxs, node, node);
+ if(spill_ctx != NULL) {
+ spill_ctx->spill = NULL;
+ }
+}
+
+void be_insert_spills_reloads(spill_env_t *env) {
+ const arch_env_t *arch_env = env->chordal_env->birg->main_env->arch_env;
+ //ir_node *node;
+ spill_info_t *si;
+
+#if 0
+ // Matze: This should be pointless as beladies fix_block_borders
+ // should result in the same
+ DBG((env->dbg, LEVEL_1, "Reloads for mem-phis:\n"));
+ foreach_pset(env->mem_phis, node) {
const ir_edge_t *e;
- DBG((senv->dbg, LEVEL_1, " Mem-phi %+F\n", irn));
- foreach_out_edge(irn, e) {
+
+ assert(is_Phi(node));
+
+ /* Add reloads for mem_phis */
+ /* BETTER: These reloads (1) should only be inserted, if they are really needed */
+ DBG((env->dbg, LEVEL_1, " Mem-phi %+F\n", node));
+ foreach_out_edge(node, e) {
ir_node *user = e->src;
- if (is_Phi(user) && !pset_find_ptr(senv->mem_phis, user)) {
- DBG((senv->dbg, LEVEL_1, " non-mem-phi user %+F\n", user));
- ir_node *use_bl = get_nodes_block(user);
- be_add_reload_on_edge(senv, irn, use_bl, e->pos);
+ if (is_Phi(user) && !pset_find_ptr(env->mem_phis, user)) {
+ ir_node *use_bl = get_nodes_block(user);
+ DBG((env->dbg, LEVEL_1, " non-mem-phi user %+F\n", user));
+ be_add_reload_on_edge(env, node, use_bl, e->pos); /* (1) */
}
}
}
+#endif
/* process each spilled node */
- DBG((senv->dbg, LEVEL_1, "Insert spills and reloads:\n"));
- for(si = set_first(senv->spills); si; si = set_next(senv->spills)) {
+ DBG((env->dbg, LEVEL_1, "Insert spills and reloads:\n"));
+ for(si = set_first(env->spills); si; si = set_next(env->spills)) {
reloader_t *rld;
- ir_node **reloads;
- int n_reloads = 0;
ir_mode *mode = get_irn_mode(si->spilled_node);
+ pset *values = pset_new_ptr(16);
/* go through all reloads for this spill */
for(rld = si->reloaders; rld; rld = rld->next) {
- /* the spill for this reloader */
- ir_node *spill = be_spill_node(senv, si->spilled_node);
-
- /* the reload */
- ir_node *bl = is_Block(rld->reloader) ? rld->reloader : get_nodes_block(rld->reloader);
- ir_node *reload = new_Reload(senv->session->main_env->node_factory,
- senv->cls, irg, bl, mode, spill);
-
- DBG((senv->dbg, LEVEL_1, " %+F of %+F before %+F\n", reload, si->spilled_node, rld->reloader));
- if(reload_set)
- pset_insert_ptr(reload_set, reload);
-
- /* remember the reaload */
- obstack_ptr_grow(&ob, reload);
- sched_add_before(rld->reloader, reload);
- n_reloads++;
- }
+ ir_node *new_val;
- assert(n_reloads > 0);
- reloads = obstack_finish(&ob);
- be_introduce_copies_ignore(senv->session->dom_front, si->spilled_node,
- n_reloads, reloads, senv->mem_phis);
- obstack_free(&ob, reloads);
- }
+ if (check_remat_conditions(env, si->spilled_node, rld->reloader)) {
+ new_val = do_remat(env, si->spilled_node, rld->reloader);
+ } else {
+ /* the spill for this reloader */
+ ir_node *spill = be_spill_node(env, si->spilled_node);
- obstack_free(&ob, NULL);
+ /* do a reload */
+ new_val = be_reload(arch_env, env->cls, rld->reloader, mode, spill);
+ }
- for(irn = pset_first(senv->mem_phis); irn; irn = pset_next(senv->mem_phis)) {
- int i, n;
- for(i = 0, n = get_irn_arity(irn); i < n; ++i)
- set_irn_n(irn, i, new_r_Bad(senv->session->irg));
- sched_remove(irn);
+ DBG((env->dbg, LEVEL_1, " %+F of %+F before %+F\n", new_val, si->spilled_node, rld->reloader));
+ pset_insert_ptr(values, new_val);
+ }
+
+ /* introduce copies, rewire the uses */
+ assert(pset_count(values) > 0 && "???");
+ pset_insert_ptr(values, si->spilled_node);
+ be_ssa_constr_set_ignore(env->chordal_env->dom_front, values, env->mem_phis);
+
+ del_pset(values);
}
- del_pset(senv->mem_phis);
+ remove_copies(env);
+
+ // reloads are placed now, but we might reuse the spill environment for further spilling decisions
+ del_set(env->spills);
+ env->spills = new_set(cmp_spillinfo, 1024);
}
-void be_add_reload(spill_env_t *senv, ir_node *to_spill, ir_node *before) {
+void be_add_reload(spill_env_t *env, ir_node *to_spill, ir_node *before) {
spill_info_t templ, *res;
reloader_t *rel;
- assert(get_irn_opcode(to_spill) != iro_Unknown);
+ assert(sched_is_scheduled(before));
+ assert(arch_irn_consider_in_reg_alloc(env->chordal_env->birg->main_env->arch_env, env->cls, to_spill));
templ.spilled_node = to_spill;
templ.reloaders = NULL;
- res = set_insert(senv->spills, &templ, sizeof(templ), HASH_PTR(to_spill));
+ res = set_insert(env->spills, &templ, sizeof(templ), HASH_PTR(to_spill));
- rel = obstack_alloc(&senv->obst, sizeof(rel[0]));
+ rel = obstack_alloc(&env->obst, sizeof(rel[0]));
rel->reloader = before;
rel->next = res->reloaders;
res->reloaders = rel;
}
-void be_add_reload_on_edge(spill_env_t *senv, ir_node *to_spill, ir_node *bl, int pos) {
- ir_node *insert_bl = get_irn_arity(bl) == 1 ? sched_first(bl) : get_Block_cfgpred_block(bl, pos);
- be_add_reload(senv, to_spill, insert_bl);
+void be_add_reload_on_edge(spill_env_t *env, ir_node *to_spill, ir_node *block, int pos) {
+ ir_node *predblock, *last;
+
+ /* simply add the reload to the beginning of the block if we only have 1 predecessor
+ * (we don't need to check for phis as there can't be any in a block with only 1 pred)
+ */
+ if(get_Block_n_cfgpreds(block) == 1) {
+ assert(!is_Phi(sched_first(block)));
+ be_add_reload(env, to_spill, sched_first(block));
+ return;
+ }
+
+ /* We have to reload the value in pred-block */
+ predblock = get_Block_cfgpred_block(block, pos);
+ last = sched_last(predblock);
+
+ /* we might have projs and keepanys behind the jump... */
+ while(is_Proj(last) || be_is_Keep(last)) {
+ last = sched_prev(last);
+ assert(!sched_is_end(last));
+ }
+ assert(is_cfop(last));
+
+ // add the reload before the (cond-)jump
+ be_add_reload(env, to_spill, last);
+}
+
+/****************************************
+
+ SPILL SLOT MANAGEMENT AND OPTS
+
+****************************************/
+
+typedef struct _spill_slot_t {
+ unsigned size;
+ unsigned align;
+ pset *members;
+ ir_mode *largest_mode; /* the mode of all members with largest size */
+} spill_slot_t;
+
+typedef struct _ss_env_t {
+ struct obstack ob;
+ be_chordal_env_t *cenv;
+ pmap *slots; /* maps spill_contexts to spill_slots */
+ pmap *types; /* maps modes to types */
+ DEBUG_ONLY(firm_dbg_module_t *dbg;)
+} ss_env_t;
+
+
+/**
+ * Walker: compute the spill slots
+ */
+static void compute_spill_slots_walker(ir_node *spill, void *env) {
+ ss_env_t *ssenv = env;
+ ir_node *ctx;
+ pmap_entry *entry;
+ spill_slot_t *ss;
+
+ if (!be_is_Spill(spill))
+ return;
+
+ /* check, if this spill is for a context already known */
+ ctx = be_get_Spill_context(spill);
+ entry = pmap_find(ssenv->slots, ctx);
+
+ if (!entry) {
+ struct _arch_env_t *arch_env = ssenv->cenv->birg->main_env->arch_env;
+ const arch_register_class_t *cls = arch_get_irn_reg_class(arch_env, spill, be_pos_Spill_val);
+ ir_mode *largest_mode = arch_register_class_mode(cls);
+
+ /* this is a new spill context */
+ ss = obstack_alloc(&ssenv->ob, sizeof(*ss));
+ ss->members = pset_new_ptr(8);
+ ss->largest_mode = largest_mode;
+ ss->size = get_mode_size_bytes(ss->largest_mode);
+ ss->align = arch_isa_get_reg_class_alignment(arch_env->isa, cls);
+ pmap_insert(ssenv->slots, ctx, ss);
+ } else {
+ /* values with the same spill_ctx must go into the same spill slot */
+ ss = entry->value;
+
+#ifndef NDEBUG
+ /* ugly mega assert :-) */
+ {
+ ir_node *irn;
+ struct _arch_env_t *arch_env = ssenv->cenv->birg->main_env->arch_env;
+ const arch_register_class_t *cls = arch_get_irn_reg_class(arch_env, spill, be_pos_Spill_val);
+ int size = get_mode_size_bytes(arch_register_class_mode(cls));
+ assert((int) ss->size == size && "Different sizes for the same spill slot are not allowed.");
+ for (irn = pset_first(ss->members); irn; irn = pset_next(ss->members)) {
+ /* use values_interfere here, because it uses the dominance check,
+ which does work for values in memory */
+ assert(!values_interfere(spill, irn) && "Spills for the same spill slot must not interfere!");
+ }
+ }
+#endif /* NDEBUG */
+ }
+
+ pset_insert_ptr(ss->members, spill);
+}
+
+/**
+ * qsort compare function, sort spill slots by size.
+ */
+static int ss_sorter(const void *v1, const void *v2) {
+ const spill_slot_t **ss1 = (const spill_slot_t **)v1;
+ const spill_slot_t **ss2 = (const spill_slot_t **)v2;
+ return ((int) (*ss2)->size) - ((int) (*ss1)->size);
+}
+
+
+/**
+ * This function should optimize the spill slots.
+ * - Coalescing of multiple slots
+ * - Ordering the slots
+ *
+ * Input slots are in @p ssenv->slots
+ * @p size The count of initial spill slots in @p ssenv->slots
+ * This also is the size of the preallocated array @p ass
+ *
+ * @return An array of spill slots @p ass in specific order
+ **/
+static void optimize_slots(ss_env_t *ssenv, int size, spill_slot_t *ass[]) {
+ int i, o, used_slots;
+ pmap_entry *entr;
+
+ i=0;
+ pmap_foreach(ssenv->slots, entr)
+ ass[i++] = entr->value;
+
+ /* Sort the array to minimize fragmentation and cache footprint.
+ Large slots come first */
+ qsort(ass, size, sizeof(ass[0]), ss_sorter);
+
+ /* For each spill slot:
+ - assign a new offset to this slot
+ - xor find another slot to coalesce with */
+ used_slots = 0;
+ for (i=0; i<size; ++i) {
+ /* for each spill slot */
+ ir_node *n1;
+ int tgt_slot = -1;
+
+ DBG((ssenv->dbg, LEVEL_1, "Spill slot %d members:\n", i));
+ for(n1 = pset_first(ass[i]->members); n1; n1 = pset_next(ass[i]->members))
+ DBG((ssenv->dbg, LEVEL_1, " %+F\n", n1));
+
+
+ for (o=0; o < used_slots && tgt_slot == -1; ++o) { /* for each offset-assigned spill slot */
+ /* check inter-slot-pairs for interference */
+ ir_node *n2;
+ for(n1 = pset_first(ass[i]->members); n1; n1 = pset_next(ass[i]->members))
+ for(n2 = pset_first(ass[o]->members); n2; n2 = pset_next(ass[o]->members))
+ if(values_interfere(n1, n2)) {
+ pset_break(ass[i]->members);
+ pset_break(ass[o]->members);
+ DBG((ssenv->dbg, LEVEL_1, " Interf %+F -- %+F\n", n1, n2));
+ goto interf_detected;
+ }
+
+ /* if we are here, there is no interference between ass[i] and ass[o] */
+ tgt_slot = o;
+
+interf_detected: /*nothing*/ ;
+ }
+
+ /* now the members of ass[i] join the members of ass[tgt_slot] */
+
+ /* do we need a new slot? */
+ if (tgt_slot == -1) {
+ tgt_slot = used_slots;
+ used_slots++;
+
+ /* init slot */
+ if (tgt_slot != i) {
+ ass[tgt_slot]->size = ass[i]->size;
+ del_pset(ass[tgt_slot]->members);
+ ass[tgt_slot]->members = pset_new_ptr(8);
+ }
+ }
+
+ /* copy the members to the target pset */
+ /* NOTE: If src and tgt pset are the same, inserting while iterating is not allowed */
+ if (tgt_slot != i)
+ for(n1 = pset_first(ass[i]->members); n1; n1 = pset_next(ass[i]->members))
+ pset_insert_ptr(ass[tgt_slot]->members, n1);
+ }
+}
+
+#define ALIGN_SPILL_AREA 16
+#define pset_foreach(pset, elm) for(elm=pset_first(pset); elm; elm=pset_next(pset))
+
+/**
+ * Returns a spill type for a mode. Keep them in a map to reduce
+ * the number of types.
+ *
+ * @param types a map containing all created types
+ * @param ss the spill slot
+ *
+ * Note that type types should are identical for every mode.
+ * This rule might break if two different register classes return the same
+ * mode but different alignments.
+ */
+static ir_type *get_spill_type(pmap *types, spill_slot_t *ss) {
+ pmap_entry *e = pmap_find(types, ss->largest_mode);
+ ir_type *res;
+
+ if (! e) {
+ char buf[64];
+ snprintf(buf, sizeof(buf), "spill_slot_type_%s", get_mode_name(ss->largest_mode));
+ buf[sizeof(buf) - 1] = '\0';
+ res = new_type_primitive(new_id_from_str(buf), ss->largest_mode);
+ set_type_alignment_bytes(res, ss->align);
+ pmap_insert(types, ss->largest_mode, res);
+ } else {
+ res = e->value;
+ assert(get_type_alignment_bytes(res) == (int)ss->align);
+ }
+
+ return res;
+}
+
+/**
+ * Create spill slot entities on the frame type.
+ *
+ * @param ssenv the spill environment
+ * @param n number of spill slots
+ * @param ss array of spill slots
+ */
+static void assign_entities(ss_env_t *ssenv, int n_slots, spill_slot_t *ss[]) {
+ int i, offset, frame_align;
+ ir_type *frame;
+
+ /* do not align the frame if no spill slots are needed */
+ if (n_slots <= 0)
+ return;
+
+ frame = get_irg_frame_type(ssenv->cenv->irg);
+
+ /* aligning by increasing frame size */
+ offset = get_type_size_bytes(frame);
+ offset = round_up2(offset, ALIGN_SPILL_AREA);
+
+ /* create entities and assign offsets according to size and alignment*/
+ for (i = 0; i < n_slots; ++i) {
+ char buf[64];
+ ident *name;
+ entity *spill_ent;
+ ir_node *irn;
+
+ /* build entity */
+ snprintf(buf, sizeof(buf), "spill_slot_%d", i);
+ buf[sizeof(buf) - 1] = '\0';
+ name = new_id_from_str(buf);
+
+ spill_ent = new_entity(frame, name, get_spill_type(ssenv->types, ss[i]));
+
+ /* align */
+ offset = round_up2(offset, ss[i]->align);
+ /* set */
+ set_entity_offset_bytes(spill_ent, offset);
+ /* next possible offset */
+ offset += round_up2(ss[i]->size, ss[i]->align);
+
+ pset_foreach(ss[i]->members, irn)
+ be_set_Spill_entity(irn, spill_ent);
+ }
+
+
+ /* set final size of stack frame */
+ frame_align = get_type_alignment_bytes(frame);
+ set_type_size_bytes(frame, round_up2(offset, frame_align));
+}
+
+void be_compute_spill_offsets(be_chordal_env_t *cenv) {
+ ss_env_t ssenv;
+ spill_slot_t **ss;
+ int ss_size;
+ pmap_entry *pme;
+
+ obstack_init(&ssenv.ob);
+ ssenv.cenv = cenv;
+ ssenv.slots = pmap_create();
+ ssenv.types = pmap_create();
+ FIRM_DBG_REGISTER(ssenv.dbg, "ir.be.spillslots");
+
+ /* Get initial spill slots */
+ irg_walk_graph(cenv->irg, NULL, compute_spill_slots_walker, &ssenv);
+
+ /* Build an empty array for optimized spill slots */
+ ss_size = pmap_count(ssenv.slots);
+ ss = obstack_alloc(&ssenv.ob, ss_size * sizeof(*ss));
+ optimize_slots(&ssenv, ss_size, ss);
+
+ /* Integrate slots into the stack frame entity */
+ assign_entities(&ssenv, ss_size, ss);
+
+ /* Clean up */
+ pmap_foreach(ssenv.slots, pme)
+ del_pset(((spill_slot_t *)pme->value)->members);
+ pmap_destroy(ssenv.slots);
+ pmap_destroy(ssenv.types);
+ obstack_free(&ssenv.ob, NULL);
+
+ be_copy_entities_to_reloads(cenv->irg);
}