create register slots in attributes on irg obstack
[libfirm] / ir / be / bespill.c
index c9d84d9..5738414 100644 (file)
 #include "entity_t.h"
 #include "debug.h"
 #include "irgwalk.h"
+#include "array.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;
 
@@ -72,7 +77,7 @@ spill_env_t *be_new_spill_env(firm_dbg_module_t *dbg,
                                                          const be_chordal_env_t *chordal_env,
                                                          decide_irn_t is_mem_phi, void *data) {
 
-       spill_env_t *env = malloc(sizeof(env[0]));
+       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;
@@ -135,11 +140,10 @@ static ir_node *be_spill_phi(spill_env_t *senv, ir_node *phi, ir_node *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]));
+    NEW_ARR_A(ir_node *, ins, n);
                for(i=0; i<n; ++i)
                        ins[i] = new_r_Unknown(irg, mode_M);
                ctx->spill = new_r_Phi(senv->chordal_env->irg, bl, n, ins, mode_M);
-               free(ins);
 
                /* re-wire the phiM */
                for(i=0; i<n; ++i) {
@@ -178,13 +182,92 @@ static void phi_walker(ir_node *irn, void *env) {
        }
 }
 
+
+#ifdef BUGGY_REMAT
+
+static int check_remat_conditions(spill_env_t *senv, ir_node *spill, ir_node *spilled, ir_node *reloader) {
+       int pos, max;
+
+       /* check for 'normal' spill and general remat condition */
+       if (!be_is_Spill(spill) || !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:      ;
+
+               }
+
+       }
+
+       return 1;
+}
+
+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));
+
+       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;
+}
+
+#endif
+
 void be_insert_spills_reloads(spill_env_t *senv, pset *reload_set) {
-       ir_graph *irg = senv->chordal_env->irg;
+       const arch_env_t *aenv = senv->chordal_env->birg->main_env->arch_env;
+       ir_graph *irg          = senv->chordal_env->irg;
        ir_node *irn;
        spill_info_t *si;
-       struct obstack ob;
-
-       obstack_init(&ob);
 
        /* get all special spilled phis */
        DBG((senv->dbg, LEVEL_1, "Mem-phis:\n"));
@@ -211,37 +294,37 @@ void be_insert_spills_reloads(spill_env_t *senv, pset *reload_set) {
        DBG((senv->dbg, LEVEL_1, "Insert spills and reloads:\n"));
        for(si = set_first(senv->spills); si; si = set_next(senv->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) {
+                       ir_node *new_val;
+
                        /* 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  = be_new_Reload(senv->cls, irg, bl, mode, spill);
+#ifdef BUGGY_REMAT
+                       if (check_remat_conditions(senv, spill, si->spilled_node, rld->reloader))
+                               new_val = do_remat(senv, si->spilled_node, rld->reloader);
+                       else
+#endif
+                               /* do a reload */
+                               new_val = be_reload(aenv, senv->cls, rld->reloader, mode, spill);
 
-                       DBG((senv->dbg, LEVEL_1, " %+F of %+F before %+F\n", reload, si->spilled_node, rld->reloader));
+                       DBG((senv->dbg, LEVEL_1, " %+F of %+F before %+F\n", new_val, si->spilled_node, rld->reloader));
+                       pset_insert_ptr(values, new_val);
                        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++;
+                               pset_insert_ptr(reload_set, new_val);
                }
 
-               assert(n_reloads > 0);
-               obstack_ptr_grow(&ob, si->spilled_node);
-               reloads = obstack_finish(&ob);
-               be_ssa_constr_ignore(senv->chordal_env->dom_front, n_reloads + 1, reloads, senv->mem_phis);
-               obstack_free(&ob, reloads);
-       }
+               /* introduce copies, rewire the uses */
+               assert(pset_count(values) > 0 && "???");
+               pset_insert_ptr(values, si->spilled_node);
+               be_ssa_constr_set_ignore(senv->chordal_env->dom_front, values, senv->mem_phis);
 
-       obstack_free(&ob, NULL);
+               del_pset(values);
+       }
 
        for(irn = pset_first(senv->mem_phis); irn; irn = pset_next(senv->mem_phis)) {
                int i, n;
@@ -313,7 +396,7 @@ static void compute_spill_slots_walker(ir_node *spill, void *env) {
                /* this is a new spill context */
                ss = obstack_alloc(&ssenv->ob, sizeof(*ss));
                ss->members = pset_new_ptr(8);
-               ss->largest_mode = get_irn_mode(get_irn_n(spill, 0));
+               ss->largest_mode = get_irn_mode(get_irn_n(spill, be_pos_Spill_val));
                ss->size = get_mode_size_bytes(ss->largest_mode);
                ss->align = ss->size; /* TODO Assumed for now */
                pmap_insert(ssenv->slots, ctx, ss);
@@ -321,7 +404,7 @@ static void compute_spill_slots_walker(ir_node *spill, void *env) {
                ir_node *irn;
                /* values with the same spill_ctx must go into the same spill slot */
                ss = entry->value;
-               assert(ss->size == (unsigned)get_mode_size_bytes(get_irn_mode(get_irn_n(spill, 0))) && "Different sizes for the same spill slot are not allowed yet.");
+               assert(ss->size == (unsigned)get_mode_size_bytes(get_irn_mode(get_irn_n(spill, be_pos_Spill_val))) && "Different sizes for the same spill slot are not allowed yet.");
                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 */
@@ -484,7 +567,7 @@ void be_compute_spill_offsets(be_chordal_env_t *cenv) {
        obstack_init(&ssenv.ob);
        ssenv.cenv  = cenv;
        ssenv.slots = pmap_create();
-  ssenv.types = pmap_create();
+       ssenv.types = pmap_create();
        ssenv.dbg   = firm_dbg_register("ir.be.spillslots");
 
        /* Get initial spill slots */
@@ -500,8 +583,10 @@ void be_compute_spill_offsets(be_chordal_env_t *cenv) {
 
        /* Clean up */
        pmap_foreach(ssenv.slots, pme)
-               del_pset(((spill_slot_t *)pme->value)->members);
+       del_pset(((spill_slot_t *)pme->value)->members);
        pmap_destroy(ssenv.slots);
-  pmap_destroy(ssenv.types);
+       pmap_destroy(ssenv.types);
        obstack_free(&ssenv.ob, NULL);
+
+       be_copy_entities_to_reloads(cenv->irg);
 }