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authorMatthias Braun <matze@braunis.de>2009-08-11 13:46:32 +0200
committerMatthias Braun <matze@braunis.de>2009-08-11 13:46:32 +0200
commitf6750fd8b384d9795d13ab2985b4a4a631a31e7e (patch)
treef12fc07e5d7dd0b410a6bf29b7dc29f938eca462 /ir/be/bespill.c
parent47b32a3377e6c02c68b864ee2cef6810d83ccb67 (diff)
- implement output constraint enforcement for new register allocator
- rename bespilloptions.* to bespill.* and bespill.* to bespillutil.* [r26327]
Diffstat (limited to 'ir/be/bespill.c')
-rw-r--r--ir/be/bespill.c1177
1 files changed, 201 insertions, 976 deletions
diff --git a/ir/be/bespill.c b/ir/be/bespill.c
index 1453688..f6d5ad2 100644
--- a/ir/be/bespill.c
+++ b/ir/be/bespill.c
@@ -19,1057 +19,282 @@
/**
* @file
- * @brief implementation of the spill/reload placement abstraction layer
- * @author Daniel Grund, Sebastian Hack, Matthias Braun
- * @date 29.09.2005
+ * @brief Spill module selection; Preparation steps
+ * @author Matthias Braun
+ * @date 29.09.2005
* @version $Id$
*/
#include "config.h"
-#include <stdlib.h>
-#include <stdbool.h>
-
-#include "pset.h"
-#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 "irtools.h"
#include "debug.h"
+#include "iredges_t.h"
+#include "adt/raw_bitset.h"
+#include "statev.h"
#include "irgwalk.h"
-#include "array.h"
-#include "pdeq.h"
-#include "execfreq.h"
-#include "irnodeset.h"
-#include "error.h"
-#include "bearch.h"
-#include "belive_t.h"
-#include "besched.h"
#include "bespill.h"
+#include "bemodule.h"
+#include "be.h"
#include "belive_t.h"
-#include "benode_t.h"
-#include "bechordal_t.h"
-#include "bespilloptions.h"
-#include "bestatevent.h"
-#include "bessaconstr.h"
#include "beirg.h"
+#include "bearch.h"
+#include "benode_t.h"
+#include "besched.h"
+#include "bera.h"
#include "beintlive_t.h"
-#include "bemodule.h"
-#include "be_t.h"
-
-DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
-
-#define REMAT_COST_INFINITE 1000
-typedef struct reloader_t reloader_t;
-struct reloader_t {
- reloader_t *next;
- ir_node *can_spill_after;
- ir_node *reloader;
- ir_node *rematted_node;
- int remat_cost_delta; /** costs needed for rematerialization,
- compared to placing a reload */
-};
-
-typedef struct spill_t spill_t;
-struct spill_t {
- spill_t *next;
- ir_node *after; /**< spill has to be placed after this node (or earlier) */
- ir_node *spill;
-};
-
-typedef struct spill_info_t spill_info_t;
-struct spill_info_t {
- ir_node *to_spill; /**< the value that should get spilled */
- reloader_t *reloaders; /**< list of places where the value should get
- reloaded */
- spill_t *spills; /**< list of latest places where spill must be
- placed */
- double spill_costs; /**< costs needed for spilling the value */
- const arch_register_class_t *reload_cls; /** the register class in which the
- reload should be placed */
-};
+#include "lc_opts.h"
+#include "lc_opts_enum.h"
-struct spill_env_t {
- const arch_env_t *arch_env;
- ir_graph *irg;
- struct obstack obst;
- be_irg_t *birg;
- 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 */
- ir_nodeset_t mem_phis; /**< set of all spilled phis. */
- ir_exec_freq *exec_freq;
+DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
-#ifdef FIRM_STATISTICS
- unsigned spill_count;
- unsigned reload_count;
- unsigned remat_count;
- unsigned spilled_phi_count;
-#endif
-};
+typedef struct be_pre_spill_env_t {
+ be_irg_t *birg;
+ const arch_register_class_t *cls;
+} be_pre_spill_env_t;
-/**
- * Compare two spill infos.
- */
-static int cmp_spillinfo(const void *x, const void *y, size_t size)
+static void prepare_constr_insn(be_pre_spill_env_t *env, ir_node *node)
{
- const spill_info_t *xx = x;
- const spill_info_t *yy = y;
- (void) size;
-
- return xx->to_spill != yy->to_spill;
-}
+ const arch_register_class_t *cls = env->cls;
+ ir_node *block = get_nodes_block(node);
+ const be_irg_t *birg = env->birg;
+ be_lv_t *lv = birg->lv;
+ unsigned *tmp = NULL;
+ unsigned *def_constr = NULL;
+ int arity = get_irn_arity(node);
+
+ int i, i2;
+
+ /* Insert a copy for constraint inputs attached to a value which can't
+ * fullfil the constraint
+ * (typical example: stack pointer as input to copyb)
+ * TODO: This really just checks precolored registers at the moment and
+ * ignore the general case of not matching in/out constraints
+ */
+ for (i = 0; i < arity; ++i) {
+ ir_node *op = get_irn_n(node, i);
+ ir_node *copy;
+ const arch_register_t *reg;
+ const arch_register_req_t *req;
+
+ req = arch_get_register_req(node, i);
+ if (req->cls != cls)
+ continue;
+ reg = arch_get_irn_register(op);
+ if (reg == NULL)
+ continue;
-/**
- * Returns spill info for a specific value (the value that is to be spilled)
- */
-static spill_info_t *get_spillinfo(const spill_env_t *env, ir_node *value)
-{
- spill_info_t info, *res;
- int hash = hash_irn(value);
+ /* precolored with an ignore register (which is not a joker like
+ unknown/noreg) */
+ if (arch_register_type_is(reg, joker)
+ || !arch_register_type_is(reg, ignore))
+ continue;
- info.to_spill = value;
- res = set_find(env->spills, &info, sizeof(info), hash);
+ if (! (req->type & arch_register_req_type_limited))
+ continue;
+ if (rbitset_is_set(req->limited, reg->index))
+ continue;
- if (res == NULL) {
- info.reloaders = NULL;
- info.spills = NULL;
- info.spill_costs = -1;
- info.reload_cls = NULL;
- res = set_insert(env->spills, &info, sizeof(info), hash);
+ copy = be_new_Copy(cls, block, op);
+ stat_ev_int("constr_copy", 1);
+ sched_add_before(node, copy);
+ set_irn_n(node, i, copy);
+ DBG((dbg, LEVEL_3, "inserting ignore arg copy %+F for %+F pos %d\n", copy, node, i));
}
- return res;
-}
+ /* insert copies for nodes that occur constrained more than once. */
+ for (i = 0; i < arity; ++i) {
+ ir_node *in;
+ ir_node *copy;
+ const arch_register_req_t *req;
-spill_env_t *be_new_spill_env(be_irg_t *birg)
-{
- const arch_env_t *arch_env = birg->main_env->arch_env;
+ req = arch_get_register_req(node, i);
+ if (req->cls != cls)
+ continue;
- spill_env_t *env = XMALLOC(spill_env_t);
- env->spills = new_set(cmp_spillinfo, 1024);
- env->irg = be_get_birg_irg(birg);
- env->birg = birg;
- env->arch_env = arch_env;
- ir_nodeset_init(&env->mem_phis);
- env->spill_cost = arch_env->spill_cost;
- env->reload_cost = arch_env->reload_cost;
- env->exec_freq = be_get_birg_exec_freq(birg);
- obstack_init(&env->obst);
+ if (! (req->type & arch_register_req_type_limited))
+ continue;
-#ifdef FIRM_STATISTICS
- env->spill_count = 0;
- env->reload_count = 0;
- env->remat_count = 0;
- env->spilled_phi_count = 0;
-#endif
+ in = get_irn_n(node, i);
+ if (!arch_irn_consider_in_reg_alloc(cls, in))
+ continue;
- return env;
-}
+ for (i2 = i + 1; i2 < arity; ++i2) {
+ ir_node *in2;
+ const arch_register_req_t *req2;
-void be_delete_spill_env(spill_env_t *env)
-{
- del_set(env->spills);
- ir_nodeset_destroy(&env->mem_phis);
- obstack_free(&env->obst, NULL);
- free(env);
-}
+ req2 = arch_get_register_req(node, i2);
+ if (req2->cls != cls)
+ continue;
+ if (! (req2->type & arch_register_req_type_limited))
+ continue;
-/*
- * ____ _ ____ _ _
- * | _ \| | __ _ ___ ___ | _ \ ___| | ___ __ _ __| |___
- * | |_) | |/ _` |/ __/ _ \ | |_) / _ \ |/ _ \ / _` |/ _` / __|
- * | __/| | (_| | (_| __/ | _ < __/ | (_) | (_| | (_| \__ \
- * |_| |_|\__,_|\___\___| |_| \_\___|_|\___/ \__,_|\__,_|___/
- *
- */
+ in2 = get_irn_n(node, i2);
+ if (in2 != in)
+ continue;
-void be_add_spill(spill_env_t *env, ir_node *to_spill, ir_node *after)
-{
- spill_info_t *spill_info = get_spillinfo(env, to_spill);
- spill_t *spill;
- spill_t *s;
- spill_t *last;
+ /* if the constraint is the same, no copy is necessary
+ * TODO generalise unequal but overlapping constraints */
+ if (rbitset_equal(req->limited, req2->limited, cls->n_regs))
+ continue;
- assert(!arch_irn_is(to_spill, dont_spill));
- DB((dbg, LEVEL_1, "Add spill of %+F after %+F\n", to_spill, after));
+#if 0
+ /* Matze: looks fishy to me disabled it for now */
+ if (be_is_Copy(get_irn_n(insn->irn, a_op->pos)))
+ continue;
+#endif
- /* Just for safety make sure that we do not insert the spill in front of a phi */
- assert(!is_Phi(sched_next(after)));
+ copy = be_new_Copy(cls, block, in);
+ stat_ev_int("constr_copy", 1);
- /* spills that are dominated by others are not needed */
- last = NULL;
- s = spill_info->spills;
- for( ; s != NULL; s = s->next) {
- /* no need to add this spill if it is dominated by another */
- if(value_dominates(s->after, after)) {
- DB((dbg, LEVEL_1, "...dominated by %+F, not added\n", s->after));
- return;
- }
- /* remove spills that we dominate */
- if(value_dominates(after, s->after)) {
- DB((dbg, LEVEL_1, "...remove old spill at %+F\n", s->after));
- if(last != NULL) {
- last->next = s->next;
- } else {
- spill_info->spills = s->next;
- }
- } else {
- last = s;
+ sched_add_before(node, copy);
+ set_irn_n(node, i2, copy);
+ DBG((dbg, LEVEL_3,
+ "inserting multiple constr copy %+F for %+F pos %d\n",
+ copy, node, i2));
}
}
- spill = obstack_alloc(&env->obst, sizeof(spill[0]));
- spill->after = after;
- spill->next = spill_info->spills;
- spill->spill = NULL;
-
- spill_info->spills = spill;
-}
-
-void be_add_remat(spill_env_t *env, ir_node *to_spill, ir_node *before,
- ir_node *rematted_node)
-{
- spill_info_t *spill_info;
- reloader_t *reloader;
-
- spill_info = get_spillinfo(env, to_spill);
+ /* collect all registers occurring in out constraints. */
+ if (get_irn_mode(node) == mode_T) {
+ const ir_edge_t *edge;
- /* add the remat information */
- reloader = obstack_alloc(&env->obst, sizeof(reloader[0]));
- reloader->next = spill_info->reloaders;
- reloader->reloader = before;
- reloader->rematted_node = rematted_node;
- reloader->remat_cost_delta = 0; /* We will never have a cost win over a
- reload since we're not even allowed to
- create a reload */
+ foreach_out_edge(node, edge) {
+ ir_node *proj = get_edge_src_irn(edge);
+ const arch_register_req_t *req = arch_get_register_req_out(proj);
+ if (! (req->type & arch_register_req_type_limited))
+ continue;
- spill_info->reloaders = reloader;
-
- DBG((dbg, LEVEL_1, "creating spillinfo for %+F, will be rematerialized before %+F\n",
- to_spill, before));
-}
-
-void be_add_reload2(spill_env_t *env, ir_node *to_spill, ir_node *before,
- ir_node *can_spill_after, const arch_register_class_t *reload_cls,
- int allow_remat)
-{
- spill_info_t *info;
- reloader_t *rel;
-
- assert(!arch_irn_is(to_spill, dont_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);
+ if (def_constr == NULL) {
+ rbitset_alloca(def_constr, cls->n_regs);
+ }
+ rbitset_or(def_constr, req->limited, cls->n_regs);
}
- }
-
- assert(!is_Proj(before) && !be_is_Keep(before));
-
- /* put reload into list */
- rel = obstack_alloc(&env->obst, sizeof(rel[0]));
- rel->next = info->reloaders;
- rel->reloader = before;
- rel->rematted_node = NULL;
- rel->can_spill_after = can_spill_after;
- rel->remat_cost_delta = allow_remat ? 0 : REMAT_COST_INFINITE;
-
- info->reloaders = rel;
- assert(info->reload_cls == NULL || info->reload_cls == reload_cls);
- info->reload_cls = reload_cls;
-
- DBG((dbg, LEVEL_1, "creating spillinfo for %+F, will be reloaded before %+F, may%s be rematerialized\n",
- to_spill, before, allow_remat ? "" : " not"));
-}
-
-void be_add_reload(spill_env_t *senv, ir_node *to_spill, ir_node *before,
- const arch_register_class_t *reload_cls, int allow_remat)
-{
- be_add_reload2(senv, to_spill, before, to_spill, reload_cls, allow_remat);
-
-}
-
-ir_node *be_get_end_of_block_insertion_point(const ir_node *block)
-{
- ir_node *last = sched_last(block);
-
- /* we might have keeps behind the jump... */
- while (be_is_Keep(last)) {
- last = sched_prev(last);
- assert(!sched_is_end(last));
- }
-
- assert(is_cfop(last));
-
- /* add the reload before the (cond-)jump */
- return last;
-}
-
-static ir_node *skip_keeps_phis(ir_node *node)
-{
- while(true) {
- ir_node *next = sched_next(node);
- if(!is_Phi(next) && !be_is_Keep(next))
- break;
- node = next;
- }
- return node;
-}
-
-/**
- * Returns the point at which you can insert a node that should be executed
- * before block @p block when coming from pred @p pos.
- */
-static ir_node *get_block_insertion_point(ir_node *block, int pos)
-{
- ir_node *predblock;
-
- /* 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);
- return be_get_end_of_block_insertion_point(predblock);
-}
-
-void be_add_reload_at_end(spill_env_t *env, ir_node *to_spill,
- const ir_node *block,
- const arch_register_class_t *reload_cls,
- int allow_remat)
-{
- ir_node *before = be_get_end_of_block_insertion_point(block);
- be_add_reload(env, to_spill, before, reload_cls, allow_remat);
-}
-
-void be_add_reload_on_edge(spill_env_t *env, ir_node *to_spill, ir_node *block,
- int pos, const arch_register_class_t *reload_cls,
- int allow_remat)
-{
- ir_node *before = get_block_insertion_point(block, pos);
- be_add_reload(env, to_spill, before, reload_cls, allow_remat);
-}
-
-void be_spill_phi(spill_env_t *env, ir_node *node)
-{
- ir_node *block;
- spill_info_t* spill;
- int i, arity;
-
- assert(is_Phi(node));
-
- ir_nodeset_insert(&env->mem_phis, node);
-
- /* create spills for the phi arguments */
- block = get_nodes_block(node);
- spill = get_spillinfo(env, node);
- for(i = 0, arity = get_irn_arity(node); i < arity; ++i) {
- ir_node *arg = get_irn_n(node, i);
- ir_node *insert;
- //get_spillinfo(env, arg);
-
- /* some backends have virtual noreg/unknown nodes that are not scheduled
- * and simply always available. */
- if(!sched_is_scheduled(arg)) {
- ir_node *pred_block = get_Block_cfgpred_block(block, i);
- insert = be_get_end_of_block_insertion_point(pred_block);
- insert = sched_prev(insert);
- } else {
- insert = skip_keeps_phis(arg);
+ } else {
+ const arch_register_req_t *req = arch_get_register_req_out(node);
+ if (req->type & arch_register_req_type_limited) {
+ rbitset_alloca(def_constr, cls->n_regs);
+ rbitset_or(def_constr, req->limited, cls->n_regs);
}
-
- be_add_spill(env, arg, insert);
}
-}
-/*
- * ____ _ ____ _ _ _
- * / ___|_ __ ___ __ _| |_ ___ / ___| _ __ (_) | |___
- * | | | '__/ _ \/ _` | __/ _ \ \___ \| '_ \| | | / __|
- * | |___| | | __/ (_| | || __/ ___) | |_) | | | \__ \
- * \____|_| \___|\__,_|\__\___| |____/| .__/|_|_|_|___/
- * |_|
- */
-
-static void determine_spill_costs(spill_env_t *env, spill_info_t *spillinfo);
-
-/**
- * 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 void spill_irn(spill_env_t *env, spill_info_t *spillinfo)
-{
- ir_node *to_spill = spillinfo->to_spill;
- spill_t *spill;
-
- /* determine_spill_costs must have been run before */
- assert(spillinfo->spill_costs >= 0);
-
- /* some backends have virtual noreg/unknown nodes that are not scheduled
- * and simply always available. */
- if(!sched_is_scheduled(to_spill)) {
- /* override spillinfos or create a new one */
- spillinfo->spills->spill = new_NoMem();
- DB((dbg, LEVEL_1, "don't spill %+F use NoMem\n", to_spill));
- return;
- }
-
- DBG((dbg, LEVEL_1, "spilling %+F ... \n", to_spill));
- spill = spillinfo->spills;
- for( ; spill != NULL; spill = spill->next) {
- ir_node *after = spill->after;
- ir_node *block = get_block(after);
-
- after = skip_keeps_phis(after);
-
- spill->spill = be_spill(block, to_spill);
- sched_add_after(skip_Proj(after), spill->spill);
- DB((dbg, LEVEL_1, "\t%+F after %+F\n", spill->spill, after));
-#ifdef FIRM_STATISTICS
- env->spill_count++;
-#endif
- }
- DBG((dbg, LEVEL_1, "\n"));
-}
-
-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
- * 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
- */
-static void spill_phi(spill_env_t *env, spill_info_t *spillinfo)
-{
- ir_graph *irg = env->irg;
- ir_node *phi = spillinfo->to_spill;
- ir_node *block = get_nodes_block(phi);
- ir_node *unknown;
- ir_node **ins;
- spill_t *spill;
- int i;
- int arity;
-
- assert(is_Phi(phi));
- assert(!get_opt_cse());
- DBG((dbg, LEVEL_1, "spilling Phi %+F:\n", phi));
-
- /* build a new PhiM */
- arity = get_irn_arity(phi);
- ins = ALLOCAN(ir_node*, arity);
- unknown = new_r_Unknown(irg, mode_M);
- for(i = 0; i < arity; ++i) {
- ins[i] = unknown;
- }
-
- /* override or replace spills list... */
- spill = obstack_alloc(&env->obst, sizeof(spill[0]));
- spill->after = skip_keeps_phis(phi);
- spill->spill = new_r_Phi(block, arity, ins, mode_M);
- spill->next = NULL;
-
- spillinfo->spills = spill;
-#ifdef FIRM_STATISTICS
- env->spilled_phi_count++;
-#endif
-
- for(i = 0; i < arity; ++i) {
- ir_node *arg = get_irn_n(phi, i);
- spill_info_t *arg_info = get_spillinfo(env, arg);
-
- determine_spill_costs(env, arg_info);
- spill_node(env, arg_info);
-
- set_irn_n(spill->spill, i, arg_info->spills->spill);
- }
- DBG((dbg, LEVEL_1, "... done spilling Phi %+F, created PhiM %+F\n", phi,
- spill->spill));
-}
-
-/**
- * Spill a node.
- *
- * @param senv the spill environment
- * @param to_spill the node that should be spilled
- */
-static void spill_node(spill_env_t *env, spill_info_t *spillinfo)
-{
- ir_node *to_spill;
-
- /* node is already spilled */
- if(spillinfo->spills != NULL && spillinfo->spills->spill != NULL)
+ /* no output constraints => we're good */
+ if (def_constr == NULL) {
return;
-
- to_spill = spillinfo->to_spill;
-
- if (is_Phi(to_spill) && ir_nodeset_contains(&env->mem_phis, to_spill)) {
- spill_phi(env, spillinfo);
- } else {
- spill_irn(env, spillinfo);
}
-}
-
-/*
- *
- * ____ _ _ _ _
- * | _ \ ___ _ __ ___ __ _| |_ ___ _ __(_) __ _| (_)_______
- * | |_) / _ \ '_ ` _ \ / _` | __/ _ \ '__| |/ _` | | |_ / _ \
- * | _ < __/ | | | | | (_| | || __/ | | | (_| | | |/ / __/
- * |_| \_\___|_| |_| |_|\__,_|\__\___|_| |_|\__,_|_|_/___\___|
- *
- */
-
-/**
- * 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, const ir_node *arg,
- const ir_node *reloader)
-{
- if(is_Unknown(arg) || arg == new_NoMem())
- return 1;
-
- if(be_is_Spill(arg))
- return 1;
-
- if(arg == get_irg_frame(env->irg))
- return 1;
-
-#if 0
- /* hack for now (happens when command should be inserted at end of block) */
- if(is_Block(reloader))
- return 0;
-#else
- (void)reloader;
-#endif
/*
- * Ignore registers are always available
+ * insert copies for all constrained arguments living through the node
+ * and being constrained to a register which also occurs in out constraints.
*/
- if (arch_irn_is_ignore(arg))
- return 1;
-
- return 0;
-}
-
-/**
- * Checks whether the node can principally be rematerialized
- */
-static int is_remat_node(const ir_node *node)
-{
- assert(!be_is_Spill(node));
-
- if (arch_irn_is(node, rematerializable))
- return 1;
-
- return 0;
-}
-
-/**
- * Check if a node is rematerializable. This tests for the following conditions:
- *
- * - 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_INFINITE if remat is not possible.
- */
-static int check_remat_conditions_costs(spill_env_t *env,
- const ir_node *spilled, const ir_node *reloader, int parentcosts)
-{
- int i, arity;
- int argremats;
- int costs = 0;
-
- if (!is_remat_node(spilled))
- return REMAT_COST_INFINITE;
+ rbitset_alloca(tmp, cls->n_regs);
+ for (i = 0; i < arity; ++i) {
+ const arch_register_req_t *req;
+ ir_node *in;
+ ir_node *copy;
+
+ /*
+ * Check, if
+ * 1) the operand is constrained.
+ * 2) lives through the node.
+ * 3) is constrained to a register occurring in out constraints.
+ */
+ req = arch_get_register_req(node, i);
+ if (req->cls != cls)
+ continue;
+ if (! (req->type & arch_register_req_type_limited))
+ continue;
- if(be_is_Reload(spilled)) {
- costs += 2;
- } else {
- costs += arch_get_op_estimated_cost(spilled);
- }
- if(parentcosts + costs >= env->reload_cost + env->spill_cost) {
- return REMAT_COST_INFINITE;
- }
- /* never rematerialize a node which modifies the flags.
- * (would be better to test wether the flags are actually live at point
- * reloader...)
- */
- if (arch_irn_is(spilled, modify_flags)) {
- return REMAT_COST_INFINITE;
- }
+ in = get_irn_n(node, i);
+ if (!arch_irn_consider_in_reg_alloc(cls, in))
+ continue;
+ if (!be_values_interfere(lv, node, in))
+ continue;
- argremats = 0;
- for(i = 0, arity = get_irn_arity(spilled); i < arity; ++i) {
- ir_node *arg = get_irn_n(spilled, i);
+ rbitset_copy(tmp, req->limited, cls->n_regs);
+ rbitset_and(tmp, def_constr, cls->n_regs);
- if(is_value_available(env, arg, reloader))
+ if (rbitset_is_empty(tmp, cls->n_regs))
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_INFINITE;
- }
- argremats++;
+ /*
+ * only create the copy if the operand is no copy.
+ * this is necessary since the assure constraints phase inserts
+ * Copies and Keeps for operands which must be different from the
+ * results. Additional copies here would destroy this.
+ */
+ if (be_is_Copy(in))
+ continue;
- costs += check_remat_conditions_costs(env, arg, reloader,
- parentcosts + costs);
- if(parentcosts + costs >= env->reload_cost + env->spill_cost)
- return REMAT_COST_INFINITE;
+ copy = be_new_Copy(cls, block, in);
+ sched_add_before(node, copy);
+ set_irn_n(node, i, copy);
+ DBG((dbg, LEVEL_3, "inserting constr copy %+F for %+F pos %d\n",
+ copy, node, i));
+ be_liveness_update(lv, in);
}
-
- return costs;
}
-/**
- * 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 *env, ir_node *spilled, ir_node *reloader)
+static void pre_spill_prepare_constr_walker(ir_node *block, void *data)
{
- int i, arity;
- ir_node *res;
- ir_node *bl;
- ir_node **ins;
-
- if(is_Block(reloader)) {
- bl = reloader;
- } else {
- bl = get_nodes_block(reloader);
- }
-
- ins = ALLOCAN(ir_node*, get_irn_arity(spilled));
- 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);
-#ifdef FIRM_STATISTICS
- /* don't count the recursive call as remat */
- env->remat_count--;
-#endif
- }
- }
-
- /* create a copy of the node */
- res = new_ir_node(get_irn_dbg_info(spilled), env->irg, bl,
- get_irn_op(spilled), get_irn_mode(spilled),
- get_irn_arity(spilled), ins);
- copy_node_attr(spilled, res);
- arch_env_mark_remat(env->arch_env, res);
- new_backedge_info(res);
-
- DBG((dbg, LEVEL_1, "Insert remat %+F of %+F before reloader %+F\n", res, spilled, reloader));
-
- if (! is_Proj(res)) {
- /* insert in schedule */
- sched_reset(res);
- sched_add_before(reloader, res);
-#ifdef FIRM_STATISTICS
- env->remat_count++;
-#endif
+ be_pre_spill_env_t *env = data;
+ ir_node *node;
+ sched_foreach(block, node) {
+ prepare_constr_insn(env, node);
}
-
- return res;
}
-double be_get_spill_costs(spill_env_t *env, ir_node *to_spill, ir_node *before)
+void be_pre_spill_prepare_constr(be_irg_t *birg,
+ const arch_register_class_t *cls)
{
- ir_node *block = get_nodes_block(before);
- double freq = get_block_execfreq(env->exec_freq, block);
- (void) to_spill;
-
- return env->spill_cost * freq;
+ ir_graph *irg = birg->irg;
+ be_pre_spill_env_t env;
+ memset(&env, 0, sizeof(env));
+ env.birg = birg;
+ env.cls = cls;
+ irg_block_walk_graph(irg, pre_spill_prepare_constr_walker, NULL, &env);
}
-unsigned be_get_reload_costs_no_weight(spill_env_t *env, const ir_node *to_spill,
- const ir_node *before)
-{
- if(be_do_remats) {
- /* is the node rematerializable? */
- unsigned costs = check_remat_conditions_costs(env, to_spill, before, 0);
- if(costs < (unsigned) env->reload_cost)
- return costs;
- }
-
- return env->reload_cost;
-}
-double be_get_reload_costs(spill_env_t *env, ir_node *to_spill, ir_node *before)
-{
- ir_node *block = get_nodes_block(before);
- double freq = get_block_execfreq(env->exec_freq, block);
- if(be_do_remats) {
- /* is the node rematerializable? */
- int costs = check_remat_conditions_costs(env, to_spill, before, 0);
- if(costs < env->reload_cost)
- return costs * freq;
- }
+int be_coalesce_spill_slots = 1;
+int be_do_remats = 1;
- return env->reload_cost * freq;
-}
-
-int be_is_rematerializable(spill_env_t *env, const ir_node *to_remat,
- const ir_node *before)
-{
- return check_remat_conditions_costs(env, to_remat, before, 0) < REMAT_COST_INFINITE;
-}
-
-double be_get_reload_costs_on_edge(spill_env_t *env, ir_node *to_spill,
- ir_node *block, int pos)
-{
- ir_node *before = get_block_insertion_point(block, pos);
- return be_get_reload_costs(env, to_spill, before);
-}
+static const lc_opt_table_entry_t be_spill_options[] = {
+ LC_OPT_ENT_BOOL ("coalesce_slots", "coalesce the spill slots", &be_coalesce_spill_slots),
+ LC_OPT_ENT_BOOL ("remat", "try to rematerialize values instead of reloading", &be_do_remats),
+ LC_OPT_LAST
+};
-/*
- * ___ _ ____ _ _
- * |_ _|_ __ ___ ___ _ __| |_ | _ \ ___| | ___ __ _ __| |___
- * | || '_ \/ __|/ _ \ '__| __| | |_) / _ \ |/ _ \ / _` |/ _` / __|
- * | || | | \__ \ __/ | | |_ | _ < __/ | (_) | (_| | (_| \__ \
- * |___|_| |_|___/\___|_| \__| |_| \_\___|_|\___/ \__,_|\__,_|___/
- *
- */
+static be_module_list_entry_t *spillers = NULL;
+static const be_spiller_t *selected_spiller = NULL;
-/**
- * analyzes how to best spill a node and determine costs for that
- */
-static void determine_spill_costs(spill_env_t *env, spill_info_t *spillinfo)
+void be_register_spiller(const char *name, be_spiller_t *spiller)
{
- ir_node *to_spill = spillinfo->to_spill;
- ir_node *spill_block;
- spill_t *spill;
- double spill_execfreq;
-
- /* already calculated? */
- if(spillinfo->spill_costs >= 0)
- return;
-
- assert(!arch_irn_is(to_spill, dont_spill));
- assert(!be_is_Reload(to_spill));
-
- /* some backends have virtual noreg/unknown nodes that are not scheduled
- * and simply always available.
- * TODO: this is kinda hairy, the NoMem is correct for an Unknown as Phi
- * predecessor (of a PhiM) but this test might match other things too...
- */
- if(!sched_is_scheduled(to_spill)) {
- /* override spillinfos or create a new one */
- spill_t *spill = obstack_alloc(&env->obst, sizeof(spill[0]));
- spill->after = NULL;
- spill->next = NULL;
- spill->spill = new_NoMem();
-
- spillinfo->spills = spill;
- spillinfo->spill_costs = 0;
-
- DB((dbg, LEVEL_1, "don't spill %+F use NoMem\n", to_spill));
- return;
- }
-
- spill_block = get_nodes_block(to_spill);
- spill_execfreq = get_block_execfreq(env->exec_freq, spill_block);
-
- if (is_Phi(to_spill) && ir_nodeset_contains(&env->mem_phis, to_spill)) {
- /* TODO calculate correct costs...
- * (though we can't remat this node anyway so no big problem) */
- spillinfo->spill_costs = env->spill_cost * spill_execfreq;
- return;
- }
-
- if(spillinfo->spills != NULL) {
- spill_t *s;
- double spills_execfreq;
-
- /* calculate sum of execution frequencies of individual spills */
- spills_execfreq = 0;
- s = spillinfo->spills;
- for( ; s != NULL; s = s->next) {
- ir_node *spill_block = get_block(s->after);
- double freq = get_block_execfreq(env->exec_freq, spill_block);
-
- spills_execfreq += freq;
- }
-
- DB((dbg, LEVEL_1, "%+F: latespillcosts %f after def: %f\n", to_spill,
- spills_execfreq * env->spill_cost,
- spill_execfreq * env->spill_cost));
-
- /* multi-/latespill is advantageous -> return*/
- if(spills_execfreq < spill_execfreq) {
- DB((dbg, LEVEL_1, "use latespills for %+F\n", to_spill));
- spillinfo->spill_costs = spills_execfreq * env->spill_cost;
- return;
- }
- }
-
- /* override spillinfos or create a new one */
- spill = obstack_alloc(&env->obst, sizeof(spill[0]));
- spill->after = skip_keeps_phis(to_spill);
- spill->next = NULL;
- spill->spill = NULL;
-
- spillinfo->spills = spill;
- spillinfo->spill_costs = spill_execfreq * env->spill_cost;
- DB((dbg, LEVEL_1, "spill %+F after definition\n", to_spill));
+ if (selected_spiller == NULL)
+ selected_spiller = spiller;
+ be_add_module_to_list(&spillers, name, spiller);
}
-void make_spill_locations_dominate_irn(spill_env_t *env, ir_node *irn)
+void be_do_spill(be_irg_t *birg, const arch_register_class_t *cls)
{
- const spill_info_t *si = get_spillinfo(env, irn);
- ir_node *start_block = get_irg_start_block(get_irn_irg(irn));
- int n_blocks = get_Block_dom_max_subtree_pre_num(start_block);
- bitset_t *reloads = bitset_alloca(n_blocks);
- reloader_t *r;
- spill_t *s;
-
- if (si == NULL)
- return;
-
- /* Fill the bitset with the dominance pre-order numbers
- * of the blocks the reloads are located in. */
- for (r = si->reloaders; r != NULL; r = r->next) {
- ir_node *bl = get_nodes_block(r->reloader);
- bitset_set(reloads, get_Block_dom_tree_pre_num(bl));
+ assert(selected_spiller != NULL);
+ if (selected_spiller != NULL) {
+ selected_spiller->spill(birg, cls);
}
-
- /* Now, cancel out all the blocks that are dominated by each spill.
- * If the bitset is not empty after that, we have reloads that are
- * not dominated by any spill. */
- for (s = si->spills; s != NULL; s = s->next) {
- ir_node *bl = get_nodes_block(s->after);
- int start = get_Block_dom_tree_pre_num(bl);
- int end = get_Block_dom_max_subtree_pre_num(bl);
-
- bitset_clear_range(reloads, start, end);
- }
-
- if (!bitset_is_empty(reloads))
- be_add_spill(env, si->to_spill, si->to_spill);
}
-void be_insert_spills_reloads(spill_env_t *env)
+void be_init_spilloptions(void)
{
- const ir_exec_freq *exec_freq = env->exec_freq;
- spill_info_t *si;
- ir_nodeset_iterator_t iter;
- ir_node *node;
-
- BE_TIMER_PUSH(t_ra_spill_apply);
-
- /* create all phi-ms first, this is needed so, that phis, hanging on
- spilled phis work correctly */
- foreach_ir_nodeset(&env->mem_phis, node, iter) {
- spill_info_t *info = get_spillinfo(env, node);
- spill_node(env, info);
- }
-
- /* process each spilled node */
- for (si = set_first(env->spills); si; si = set_next(env->spills)) {
- reloader_t *rld;
- ir_node *to_spill = si->to_spill;
- ir_mode *mode = get_irn_mode(to_spill);
- ir_node **copies = NEW_ARR_F(ir_node*, 0);
- double all_remat_costs = 0; /** costs when we would remat all nodes */
- int force_remat = 0;
-
- DBG((dbg, LEVEL_1, "\nhandling all reloaders of %+F:\n", to_spill));
+ lc_opt_entry_t *be_grp = lc_opt_get_grp(firm_opt_get_root(), "be");
+ lc_opt_entry_t *spill_grp = lc_opt_get_grp(be_grp, "spill");
- determine_spill_costs(env, si);
+ lc_opt_add_table(spill_grp, be_spill_options);
+ be_add_module_list_opt(spill_grp, "spiller", "spill algorithm",
+ &spillers, (void**) &selected_spiller);
- /* determine possibility of rematerialisations */
- if(be_do_remats) {
- /* calculate cost savings for each indivial value when it would
- be rematted instead of reloaded */
- for (rld = si->reloaders; rld != NULL; rld = rld->next) {
- double freq;
- int remat_cost;
- int remat_cost_delta;
- ir_node *block;
- ir_node *reloader = rld->reloader;
-
- if(rld->rematted_node != NULL) {
- DBG((dbg, LEVEL_2, "\tforced remat %+F before %+F\n",
- rld->rematted_node, reloader));
- continue;
- }
- if(rld->remat_cost_delta >= REMAT_COST_INFINITE) {
- DBG((dbg, LEVEL_2, "\treload before %+F is forbidden\n",
- reloader));
- all_remat_costs = REMAT_COST_INFINITE;
- continue;
- }
-
- remat_cost = check_remat_conditions_costs(env, to_spill,
- reloader, 0);
- if(remat_cost >= REMAT_COST_INFINITE) {
- DBG((dbg, LEVEL_2, "\tremat before %+F not possible\n",
- reloader));
- rld->remat_cost_delta = REMAT_COST_INFINITE;
- all_remat_costs = REMAT_COST_INFINITE;
- continue;
- }
-
- remat_cost_delta = remat_cost - env->reload_cost;
- rld->remat_cost_delta = remat_cost_delta;
- block = is_Block(reloader) ? reloader : get_nodes_block(reloader);
- freq = get_block_execfreq(exec_freq, block);
- all_remat_costs += remat_cost_delta * freq;
- DBG((dbg, LEVEL_2, "\tremat costs delta before %+F: "
- "%d (rel %f)\n", reloader, remat_cost_delta,
- remat_cost_delta * freq));
- }
- if(all_remat_costs < REMAT_COST_INFINITE) {
- /* we don't need the costs for the spill if we can remat
- all reloaders */
- all_remat_costs -= si->spill_costs;
-
- DBG((dbg, LEVEL_2, "\tspill costs %d (rel %f)\n",
- env->spill_cost, si->spill_costs));
- }
-
- if(all_remat_costs < 0) {
- DBG((dbg, LEVEL_1, "\nforcing remats of all reloaders (%f)\n",
- all_remat_costs));
- force_remat = 1;
- }
- }
-
- /* go through all reloads for this spill */
- for (rld = si->reloaders; rld != NULL; rld = rld->next) {
- ir_node *copy; /* a reload is a "copy" of the original value */
-
- if (rld->rematted_node != NULL) {
- copy = rld->rematted_node;
- sched_add_before(rld->reloader, copy);
- } else if (be_do_remats &&
- (force_remat || rld->remat_cost_delta < 0)) {
- copy = do_remat(env, to_spill, rld->reloader);
- } else {
- /* make sure we have a spill */
- spill_node(env, si);
-
- /* create a reload, use the first spill for now SSA
- * reconstruction for memory comes below */
- assert(si->spills != NULL);
- copy = be_reload(si->reload_cls, rld->reloader, mode,
- si->spills->spill);
-#ifdef FIRM_STATISTICS
- env->reload_count++;
-#endif
- }
-
- DBG((dbg, LEVEL_1, " %+F of %+F before %+F\n",
- copy, to_spill, rld->reloader));
- ARR_APP1(ir_node*, copies, copy);
- }
-
- /* if we had any reloads or remats, then we need to reconstruct the
- * SSA form for the spilled value */
- if (ARR_LEN(copies) > 0) {
- be_ssa_construction_env_t senv;
- /* be_lv_t *lv = be_get_birg_liveness(env->birg); */
-
- be_ssa_construction_init(&senv, env->birg);
- be_ssa_construction_add_copy(&senv, to_spill);
- be_ssa_construction_add_copies(&senv, copies, ARR_LEN(copies));
- be_ssa_construction_fix_users(&senv, to_spill);
-
-#if 0
- /* no need to enable this as long as we invalidate liveness
- after this function... */
- be_ssa_construction_update_liveness_phis(&senv);
- be_liveness_update(to_spill);
- len = ARR_LEN(copies);
- for(i = 0; i < len; ++i) {
- be_liveness_update(lv, copies[i]);
- }
-#endif
- be_ssa_construction_destroy(&senv);
- }
- /* need to reconstruct SSA form if we had multiple spills */
- if (si->spills != NULL && si->spills->next != NULL) {
- spill_t *spill;
- int spill_count = 0;
-
- be_ssa_construction_env_t senv;
-
- be_ssa_construction_init(&senv, env->birg);
- spill = si->spills;
- for( ; spill != NULL; spill = spill->next) {
- /* maybe we rematerialized the value and need no spill */
- if(spill->spill == NULL)
- continue;
- be_ssa_construction_add_copy(&senv, spill->spill);
- spill_count++;
- }
- if(spill_count > 1) {
- /* all reloads are attached to the first spill, fix them now */
- be_ssa_construction_fix_users(&senv, si->spills->spill);
- }
-
- be_ssa_construction_destroy(&senv);
- }
-
- DEL_ARR_F(copies);
- si->reloaders = NULL;
- }
-
- stat_ev_dbl("spill_spills", env->spill_count);
- stat_ev_dbl("spill_reloads", env->reload_count);
- stat_ev_dbl("spill_remats", env->remat_count);
- stat_ev_dbl("spill_spilled_phis", env->spilled_phi_count);
-
- /* Matze: In theory be_ssa_construction should take care of the liveness...
- * try to disable this again in the future */
- be_liveness_invalidate(env->birg->lv);
-
- be_remove_dead_nodes_from_schedule(env->birg);
-
- BE_TIMER_POP(t_ra_spill_apply);
-}
-
-void be_init_spill(void)
-{
- FIRM_DBG_REGISTER(dbg, "firm.be.spill");
+ FIRM_DBG_REGISTER(dbg, "firm.be.spillprepare");
}
-BE_REGISTER_MODULE_CONSTRUCTOR(be_init_spill);
+BE_REGISTER_MODULE_CONSTRUCTOR(be_init_spilloptions);