-/**
- * Author: Daniel Grund, Sebastian Hack
+/*
+ * Author: Daniel Grund, Sebastian Hack, Matthias Braun
* Date: 29.09.2005
* Copyright: (c) Universitaet Karlsruhe
* Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
#include "irnode_t.h"
#include "ircons_t.h"
#include "iredges_t.h"
+#include "irbackedge_t.h"
+#include "irprintf.h"
#include "ident_t.h"
#include "type_t.h"
#include "entity_t.h"
#include "irgwalk.h"
#include "array.h"
#include "pdeq.h"
+#include "unionfind.h"
+#include "execfreq.h"
#include "belive_t.h"
#include "besched_t.h"
#include "bespill.h"
+#include "belive_t.h"
#include "benode_t.h"
#include "bechordal_t.h"
+#include "bejavacoal.h"
+#include "benodesets.h"
-/* This enables re-computation of values. Current state: Unfinished and buggy. */
-#undef BUGGY_REMAT
+// only rematerialise when costs are less than REMAT_COST_LIMIT
+// TODO determine a good value here...
+#define REMAT_COST_LIMIT 10
typedef struct _reloader_t reloader_t;
-typedef struct _spill_info_t spill_info_t;
struct _reloader_t {
reloader_t *next;
ir_node *reloader;
};
-struct _spill_info_t {
+typedef struct _spill_info_t {
+ /** the value that should get spilled */
ir_node *spilled_node;
+ /** list of places where the value should get reloaded */
reloader_t *reloaders;
-};
-typedef struct _spill_ctx_t {
- ir_node *spilled; /**< The spilled node. */
- ir_node *user; /**< The node this spill is for. */
- ir_node *spill; /**< The spill itself. */
-} spill_ctx_t;
+ /** the spill node, or a PhiM node */
+ ir_node *spill;
+ /** if we had the value of a phi spilled before but not the phi itself then
+ * this field contains the spill for the phi value */
+ ir_node *old_spill;
+} spill_info_t;
struct _spill_env_t {
const arch_register_class_t *cls;
+ const arch_env_t *arch_env;
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 separately */
- ir_node **copies; /**< set of copies placed because of phi spills */
+ int spill_cost; /**< the cost of a single spill node */
+ int reload_cost; /**< the cost of a reload node */
+ set *spills; /**< all spill_info_t's, which must be placed */
+ pset *mem_phis; /**< set of all special spilled phis. allocated and freed separately */
+
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.
+ * Compare two spill infos.
*/
-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;
+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;
}
/**
- * compare two spill contexts.
+ * Returns spill info for a specific value (returns NULL if the info doesn't
+ * exist yet)
*/
-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;
+static spill_info_t *find_spillinfo(const spill_env_t *env, ir_node *value) {
+ spill_info_t info;
+ int hash = nodeset_hash(value);
+
+ info.spilled_node = value;
+
+ return set_find(env->spills, &info, sizeof(info), hash);
}
/**
- * Compare two spill infos.
+ * Returns spill info for a specific value (the value that is to be spilled)
*/
-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;
+static spill_info_t *get_spillinfo(const spill_env_t *env, ir_node *value) {
+ spill_info_t info, *res;
+ int hash = nodeset_hash(value);
+
+ info.spilled_node = value;
+ res = set_find(env->spills, &info, sizeof(info), hash);
+
+ if (res == NULL) {
+ info.reloaders = NULL;
+ info.spill = NULL;
+ info.old_spill = NULL;
+ res = set_insert(env->spills, &info, sizeof(info), hash);
+ }
+
+ return res;
}
DEBUG_ONLY(
/* 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->arch_env = env->chordal_env->birg->main_env->arch_env;
env->mem_phis = pset_new_ptr_default();
- env->copies = NEW_ARR_F(ir_node*, 0);
+ // TODO, ask backend about costs...
+ env->spill_cost = 8;
+ env->reload_cost = 5;
obstack_init(&env->obst);
return env;
}
/* 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;
- templ.spilled = to_spill;
- templ.user = ctx_irn;
- templ.spill = NULL;
+void be_add_reload(spill_env_t *env, ir_node *to_spill, ir_node *before) {
+ spill_info_t *info;
+ reloader_t *rel;
+
+ assert(sched_is_scheduled(before));
+ assert(arch_irn_consider_in_reg_alloc(env->arch_env, env->cls, to_spill));
+
+ info = get_spillinfo(env, to_spill);
+
+ if(is_Phi(to_spill)) {
+ int i, arity;
+ // create spillinfos for the phi arguments
+ for(i = 0, arity = get_irn_arity(to_spill); i < arity; ++i) {
+ ir_node *arg = get_irn_n(to_spill, i);
+ get_spillinfo(env, arg);
+ }
+ }
+
+ rel = obstack_alloc(&env->obst, sizeof(rel[0]));
+ rel->reloader = before;
+ rel->next = info->reloaders;
+ info->reloaders = rel;
+}
+
+static ir_node *get_reload_insertion_point(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)));
+ return sched_first(block);
+ }
+
+ /* 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));
- return set_insert(sc, &templ, sizeof(templ), HASH_COMBINE(HASH_PTR(to_spill), HASH_PTR(ctx_irn)));
+ // add the reload before the (cond-)jump
+ return last;
}
+void be_add_reload_on_edge(spill_env_t *env, ir_node *to_spill, ir_node *block, int pos) {
+ ir_node *before = get_reload_insertion_point(block, pos);
+ be_add_reload(env, to_spill, before);
+}
+
+void be_spill_phi(spill_env_t *env, ir_node *node) {
+ spill_info_t* spill;
+ int i, arity;
+
+ assert(is_Phi(node));
+
+ pset_insert_ptr(env->mem_phis, node);
+
+ // create spillinfos for the phi arguments
+ spill = get_spillinfo(env, node);
+ for(i = 0, arity = get_irn_arity(node); i < arity; ++i) {
+ ir_node *arg = get_irn_n(node, i);
+ get_spillinfo(env, arg);
+ }
+
+ // if we had a spill for the phi value before, then remove this spill from
+ // schedule, as we will remove it in the insert spill/reload phase
+ if(spill->spill != NULL && !is_Phi(spill->spill)) {
+ spill->old_spill = spill->spill;
+ spill->spill = NULL;
+ }
+}
+
+/*
+ * ____ _ ____ _ _ _
+ * / ___|_ __ ___ __ _| |_ ___ / ___| _ __ (_) | |___
+ * | | | '__/ _ \/ _` | __/ _ \ \___ \| '_ \| | | / __|
+ * | |___| | | __/ (_| | || __/ ___) | |_) | | | \__ \
+ * \____|_| \___|\__,_|\__\___| |____/| .__/|_|_|_|___/
+ * |_|
+ */
+
/**
* Schedules a node after an instruction. (That is the place after all projs and phis
* that are scheduled after the instruction)
+ * This function also skips phi nodes at the beginning of a block
*/
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;
+ while(is_Proj(next) || is_Phi(next)) {
next = sched_next(next);
}
+ assert(next != NULL);
if(sched_is_end(next)) {
- next = sched_last(get_nodes_block(sched_after));
- sched_add_after(next, node);
+ sched_add_after(sched_last(get_nodes_block(sched_after)), node);
} else {
sched_add_before(next, 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;
- 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));
+static void spill_irn(spill_env_t *env, spill_info_t *spillinfo) {
+ ir_node *to_spill = spillinfo->spilled_node;
- // Has the value already been spilled?
- ctx = be_get_spill_ctx(senv->spill_ctxs, irn, ctx_irn);
- if(ctx->spill)
- return ctx->spill;
+ DBG((env->dbg, LEVEL_1, "%+F\n", to_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
+ *
+ * (although rematerialization code should handle most of these cases
+ * this can still happen when spilling Phis)
*/
- if(be_is_Reload(irn)) {
- return get_irn_n(irn, be_pos_Reload_mem);
+ if(be_is_Reload(to_spill)) {
+ spillinfo->spill = get_irn_n(to_spill, be_pos_Reload_mem);
+ return;
}
- ctx->spill = be_spill(env->arch_env, irn, ctx_irn);
- sched_add_after_insn(irn, ctx->spill);
-
- return ctx->spill;
-}
-
-/**
- * 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);
- }
+ if (arch_irn_is(env->arch_env, to_spill, dont_spill)) {
+ if (env->chordal_env->opts->vrfy_option == BE_CH_VRFY_WARN)
+ ir_fprintf(stderr, "Verify warning: spilling 'dont_spill' node %+F\n", to_spill);
+ else if (env->chordal_env->opts->vrfy_option == BE_CH_VRFY_ASSERT)
+ assert(0 && "Attempt to spill a node marked 'dont_spill'");
}
- ARR_SETLEN(ir_node*, env->copies, 0);
+ spillinfo->spill = be_spill(env->arch_env, to_spill);
+ sched_add_after_insn(to_spill, spillinfo->spill);
}
-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);
-}
+static void spill_node(spill_env_t *env, spill_info_t *spillinfo);
/**
* If the first usage of a Phi result would be out of 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 *spill_phi(spill_env_t *senv, ir_node *phi, ir_node *ctx_irn, set *already_visited_phis, bitset_t *bs) {
- int i;
+static void spill_phi(spill_env_t *env, spill_info_t *spillinfo) {
+ ir_node *phi = spillinfo->spilled_node;
+ 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;
+ ir_node *block = get_nodes_block(phi);
+ ir_node **ins;
assert(is_Phi(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);
+ ins = alloca(sizeof(ir_node*) * arity);
+ for(i = 0; i < arity; ++i) {
+ ins[i] = get_irg_bad(env->chordal_env->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) {
- /* collect all arguments of the phi */
- for (i = 0; i < arity; ++i) {
- ir_node *arg = get_irn_n(phi, i);
- ir_node *sub_res;
- 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);
- }
+ spillinfo->spill = new_r_Phi(env->chordal_env->irg, block, arity, ins, mode_M);
- set_irn_n(phi_spill, i, sub_res);
- }
+ for(i = 0; i < arity; ++i) {
+ ir_node *arg = get_irn_n(phi, i);
+ spill_info_t *arg_info = get_spillinfo(env, arg);
- ctx->spill = phi_spill;
+ spill_node(env, arg_info);
+
+ set_irn_n(spillinfo->spill, i, arg_info->spill);
+ }
+
+ // rewire reloads from old_spill to phi
+ if(spillinfo->old_spill != NULL) {
+ const ir_edge_t *edge, *next;
+ foreach_out_edge_safe(spillinfo->old_spill, edge, next) {
+ ir_node* reload = get_edge_src_irn(edge);
+ assert(be_is_Reload(reload) || is_Phi(reload));
+ set_irn_n(reload, get_edge_src_pos(edge), spillinfo->spill);
+ }
+ spillinfo->old_spill = NULL;
}
- return ctx->spill;
}
/**
*
* @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_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);
+static void spill_node(spill_env_t *env, spill_info_t *spillinfo) {
+ ir_node *to_spill;
+
+ // the node should be tagged for spilling already...
+ if(spillinfo->spill != NULL)
+ return;
+
+ to_spill = spillinfo->spilled_node;
+ if (is_Phi(to_spill) && pset_find_ptr(env->mem_phis, spillinfo->spilled_node)) {
+ spill_phi(env, spillinfo);
} else {
- res = be_spill_irn(senv, to_spill, to_spill);
+ spill_irn(env, spillinfo);
}
-
- return res;
}
-#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;
+/**
+ * Tests whether value @p arg is available before node @p reloader
+ * @returns 1 if value is available, 0 otherwise
+ */
+static int is_value_available(spill_env_t *env, ir_node *arg, ir_node *reloader) {
+ if(is_Unknown(arg) || arg == new_NoMem())
+ return 1;
- /* check availability of original arguments */
- if (is_Block(reloader)) {
+ if(be_is_Spill(arg))
+ return 1;
- /* 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;
- }
+ if(arg == get_irg_frame(env->chordal_env->irg))
+ return 1;
- } else {
+ /* the following test does not work while spilling,
+ * because the liveness info is not adapted yet to the effects of the
+ * additional spills/reloads.
+ *
+ * So we can only do this test for ignore registers (of our register class)
+ */
+ if(arch_get_irn_reg_class(env->arch_env, arg, -1) == env->chordal_env->cls
+ && arch_irn_is(env->arch_env, arg, ignore)) {
+ int i, arity;
/* 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;
+ if (values_interfere(env->chordal_env->lv, reloader, arg)) {
+ return 1;
+ }
- 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;
- }
+ arity = get_irn_arity(reloader);
+ for (i = 0; i < arity; ++i) {
+ ir_node *rel_arg = get_irn_n(reloader, i);
+ if (rel_arg == arg)
+ return 1;
+ }
+ }
- /* arg is not alive before reloader */
- return 0;
+ return 0;
+}
-is_alive: ;
+/**
+ * Checks whether the node can principally be rematerialized
+ */
+static int is_remat_node(spill_env_t *env, ir_node *node) {
+ const arch_env_t *arch_env = env->arch_env;
- }
+ assert(!be_is_Spill(node));
+ if(arch_irn_is(arch_env, node, rematerializable)) {
+ return 1;
}
- return 1;
-}
+ if(be_is_StackParam(node))
+ return 1;
-#else /* BUGGY_REMAT */
+ return 0;
+}
/**
- * A very simple rematerialization checker.
+ * Check if a node is rematerializable. This tests for the following conditions:
*
- * @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
+ * - The node itself is rematerializable
+ * - All arguments of the node are available or also rematerialisable
+ * - The costs for the rematerialisation operation is less or equal a limit
+ *
+ * Returns the costs needed for rematerialisation or something
+ * > REMAT_COST_LIMIT if remat is not possible.
*/
-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;
+static int check_remat_conditions_costs(spill_env_t *env, ir_node *spilled, ir_node *reloader, int parentcosts) {
+ int i, arity;
+ int argremats;
+ int costs = 0;
+
+ if(!is_remat_node(env, spilled))
+ return REMAT_COST_LIMIT;
+
+ if(be_is_Reload(spilled)) {
+ costs += 2;
+ } else {
+ costs += arch_get_op_estimated_cost(env->arch_env, spilled);
+ }
+ if(parentcosts + costs >= REMAT_COST_LIMIT) {
+ return REMAT_COST_LIMIT;
+ }
+
+ argremats = 0;
+ for(i = 0, arity = get_irn_arity(spilled); i < arity; ++i) {
+ ir_node *arg = get_irn_n(spilled, i);
+
+ if(is_value_available(env, arg, reloader))
+ continue;
+
+ // we have to rematerialize the argument as well...
+ if(argremats >= 1) {
+ /* we only support rematerializing 1 argument at the moment,
+ * so that we don't have to care about register pressure
+ */
+ return REMAT_COST_LIMIT;
+ }
+ argremats++;
+
+ costs += check_remat_conditions_costs(env, arg, reloader, parentcosts + costs);
+ if(parentcosts + costs >= REMAT_COST_LIMIT)
+ return REMAT_COST_LIMIT;
+ }
- return get_irn_arity(spilled) == 0 &&
- arch_irn_is(aenv, spilled, rematerializable);
+ return costs;
}
-#endif /* BUGGY_REMAT */
+static int check_remat_conditions(spill_env_t *env, ir_node *spilled, ir_node *reloader) {
+ int costs = check_remat_conditions_costs(env, spilled, reloader, 0);
+
+ return costs < REMAT_COST_LIMIT;
+}
/**
* Re-materialize a node.
* @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) {
+static ir_node *do_remat(spill_env_t *env, ir_node *spilled, ir_node *reloader) {
+ int i, arity;
ir_node *res;
- ir_node *bl = (is_Block(reloader)) ? reloader : get_nodes_block(reloader);
+ ir_node *bl = get_nodes_block(reloader);
+ ir_node **ins;
+
+ ins = alloca(get_irn_arity(spilled) * sizeof(ins[0]));
+ for(i = 0, arity = get_irn_arity(spilled); i < arity; ++i) {
+ ir_node *arg = get_irn_n(spilled, i);
+
+ if(is_value_available(env, arg, reloader)) {
+ ins[i] = arg;
+ } else {
+ ins[i] = do_remat(env, arg, reloader);
+ }
+ }
- /* recompute the value */
- res = new_ir_node(get_irn_dbg_info(spilled), senv->chordal_env->irg, bl,
+ /* create a copy of the node */
+ res = new_ir_node(get_irn_dbg_info(spilled), env->chordal_env->irg, bl,
get_irn_op(spilled),
get_irn_mode(spilled),
get_irn_arity(spilled),
- get_irn_in(spilled) + 1);
+ ins);
copy_node_attr(spilled, res);
+ new_backedge_info(res);
- DBG((senv->dbg, LEVEL_1, "Insert remat %+F before reloader %+F\n", res, reloader));
+ DBG((env->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);
- }
+ assert(!is_Block(reloader));
+ sched_add_before(reloader, res);
return res;
}
-static place_copies_for_phi(spill_env_t *env, ir_node* node) {
- int i, arity;
+int be_get_reload_costs(spill_env_t *env, ir_node *to_spill, ir_node *before) {
+ spill_info_t *spill_info;
- 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);
+ // is the node rematerializable?
+ int costs = check_remat_conditions_costs(env, to_spill, before, 0);
+ if(costs < REMAT_COST_LIMIT)
+ return costs;
- ARR_APP1(ir_node*, env->copies, copy);
- insert_point = find_last_use_def(env, pred_block, arg);
- sched_add_before(insert_point, copy);
+ // do we already have a spill?
+ spill_info = find_spillinfo(env, to_spill);
+ if(spill_info != NULL && spill_info->spill != NULL)
+ return env->reload_cost;
- set_irn_n(node, i, copy);
- }
+ return env->spill_cost + env->reload_cost;
}
-void be_place_copies(spill_env_t *env) {
- ir_node *node;
-
- foreach_pset(env->mem_phis, node) {
- place_copies_for_phi(env, node);
- }
+int be_get_reload_costs_on_edge(spill_env_t *env, ir_node *to_spill, ir_node *block, int pos) {
+ ir_node *before = get_reload_insertion_point(block, pos);
+ return be_get_reload_costs(env, to_spill, before);
}
-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;
+ const arch_env_t *arch_env = env->arch_env;
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;
-
- 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(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((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_mode *mode = get_irn_mode(si->spilled_node);
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);
+ /* make sure we have a spill */
+ spill_node(env, si);
/* do a reload */
- new_val = be_reload(arch_env, env->cls, rld->reloader, mode, spill);
+ new_val = be_reload(arch_env, env->cls, rld->reloader, mode, si->spill);
}
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);
- }
-
- 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 *env, ir_node *to_spill, ir_node *before) {
- spill_info_t templ, *res;
- reloader_t *rel;
-
- 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(env->spills, &templ, sizeof(templ), HASH_PTR(to_spill));
-
- 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 *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;
- arch_env_t *arch_env = ssenv->cenv->birg->main_env->arch_env;
- ir_node *ctx;
- pmap_entry *entry;
- spill_slot_t *ss;
- const arch_register_class_t *cls;
-
- if (! be_is_Spill(spill))
- return;
-
- cls = arch_get_irn_reg_class(arch_env, spill, be_pos_Spill_val);
-
- if (cls != ssenv->cenv->cls)
- 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) {
- 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);
- }
+ if(pset_count(values) > 0) {
+ /* introduce copies, rewire the uses */
+ pset_insert_ptr(values, si->spilled_node);
+ be_ssa_constr_set_ignore(env->chordal_env->dom_front, env->chordal_env->lv, values, env->mem_phis);
}
- /* 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);
+ del_pset(values);
- pset_foreach(ss[i]->members, irn)
- be_set_Spill_entity(irn, spill_ent);
+ si->reloaders = NULL;
}
-
- /* 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, "firm.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);
+ be_remove_dead_nodes_from_schedule(env->chordal_env->irg);
+ be_liveness_recompute(env->chordal_env->lv);
}
projects / libfirm / blobdiff