no environment anymore for emitters
[libfirm] / ir / be / belower.c
index 9d665f8..42c887e 100644 (file)
  */
 
 /**
- * Author:      Christian Wuerdig
- * Date:        2005/12/14
- * Copyright:   (c) Universitaet Karlsruhe
- * Licence:     This file protected by GPL -  GNU GENERAL PUBLIC LICENSE.
- * CVS-Id:      $Id$
- *
- * Performs lowering of perm nodes and spill/reload optimization.
+ * @file
+ * @brief       Performs lowering of perm nodes. Inserts copies to assure register constraints.
+ * @author      Christian Wuerdig
+ * @date        14.12.2005
+ * @version     $Id$
  */
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #include "debug.h"
 #include "irhooks.h"
 #include "xmalloc.h"
+#include "irnodeset.h"
+#include "irgmod.h"
+#include "iredges_t.h"
+#include "irgwalk.h"
 
 #include "bearch_t.h"
 #include "belower.h"
 #include "besched_t.h"
 #include "bestat.h"
 #include "bessaconstr.h"
-#include "irnodeset.h"
-
-#include "irgmod.h"
-#include "iredges_t.h"
-#include "irgwalk.h"
+#include "benodesets.h"
+#include "beintlive_t.h"
 
 #undef KEEP_ALIVE_COPYKEEP_HACK
 
@@ -99,6 +98,7 @@ typedef struct _perm_cycle_t {
        perm_type_t             type;        /**< type (CHAIN or CYCLE) */
 } perm_cycle_t;
 
+//
 /* Compare the two operands */
 static int cmp_op_copy_assoc(const void *a, const void *b) {
        const op_copy_assoc_t *op1 = a;
@@ -309,6 +309,7 @@ static void lower_perm_node(ir_node *irn, void *walk_env) {
                        should be ok.
        */
        sched_point = sched_prev(irn);
+       DBG((mod, LEVEL_1, "perm: %+F\n", irn));
        DBG((mod, LEVEL_1, "sched point is %+F\n", sched_point));
        assert(sched_point && "Perm is not scheduled or has no predecessor");
 
@@ -349,9 +350,6 @@ static void lower_perm_node(ir_node *irn, void *walk_env) {
                                set_Proj_proj(pairs[i].out_node, get_Proj_proj(pairs[i].in_node));
                        }
 
-                       /* remove the proj from the schedule */
-                       sched_remove(pairs[i].out_node);
-
                        /* reroute the edges from the proj to the argument */
                        exchange(pairs[i].out_node, pairs[i].in_node);
                        //edges_reroute(pairs[i].out_node, pairs[i].in_node, env->birg->irg);
@@ -463,20 +461,12 @@ static void lower_perm_node(ir_node *irn, void *walk_env) {
                                        /* set as in for next Perm */
                                        pairs[pidx].in_node = res1;
                                }
-                               else {
-                                       sched_remove(res1);
-                               }
-
-                               sched_remove(res2);
 
                                set_Proj_pred(res2, cpyxchg);
                                set_Proj_proj(res2, 0);
                                set_Proj_pred(res1, cpyxchg);
                                set_Proj_proj(res1, 1);
 
-                               sched_add_after(sched_point, res1);
-                               sched_add_after(sched_point, res2);
-
                                arch_set_irn_register(arch_env, res2, cycle->elems[i + 1]);
                                arch_set_irn_register(arch_env, res1, cycle->elems[i]);
 
@@ -496,9 +486,6 @@ static void lower_perm_node(ir_node *irn, void *walk_env) {
                                arch_set_irn_register(arch_env, cpyxchg, cycle->elems[i + 1]);
                                n_ops++;
 
-                               /* remove the proj from the schedule */
-                               sched_remove(res2);
-
                                /* exchange copy node and proj */
                                exchange(res2, cpyxchg);
 
@@ -873,10 +860,158 @@ void assure_constraints(be_irg_t *birg) {
 
        del_pset(cenv.op_set);
        obstack_free(&cenv.obst, NULL);
-       be_invalidate_liveness(birg);
+       be_liveness_invalidate(be_get_birg_liveness(birg));
 }
 
 
+/**
+ * Push nodes that do not need to be permed through the Perm.
+ * This is commonly a reload cascade at block ends.
+ * @note This routine needs interference.
+ * @note Probably, we can implement it a little more efficient.
+ *       Especially searching the frontier lazily might be better.
+ * @param perm The perm.
+ * @param data The walker data (lower_env_t).
+ * @return     1, if there is something left to perm over.
+ *             0, if removed the complete perm.
+ */
+static int push_through_perm(ir_node *perm, void *data)
+{
+       lower_env_t *env       = data;
+       const arch_env_t *aenv = env->arch_env;
+
+       ir_graph *irg     = get_irn_irg(perm);
+       ir_node *bl       = get_nodes_block(perm);
+       ir_node *node;
+       int  arity        = get_irn_arity(perm);
+       int *map;
+       int *proj_map;
+       bitset_t *moved   = bitset_alloca(arity);
+       int n_moved;
+       int new_size;
+       ir_node *frontier = sched_first(bl);
+       FIRM_DBG_REGISTER(firm_dbg_module_t *mod, "firm.be.lower.permmove");
+
+       int i, n;
+       const ir_edge_t *edge;
+       ir_node *last_proj, *irn;
+       const arch_register_class_t *cls;
+
+       DBG((mod, LEVEL_1, "perm move %+F irg %+F\n", perm, irg));
+
+       /* get some proj and find out the register class of the proj. */
+       foreach_out_edge (perm, edge) {
+               last_proj  = get_edge_src_irn(edge);
+               cls = arch_get_irn_reg_class(aenv, last_proj, -1);
+               assert(is_Proj(last_proj));
+               break;
+       }
+
+       /* find the point in the schedule after which the
+        * potentially movable nodes must be defined.
+        * A perm will only be pushed up to first instruction
+        * which lets an operand of itself die.  */
+
+       sched_foreach_reverse_from (sched_prev(perm), irn) {
+               for(i = get_irn_arity(irn) - 1; i >= 0; --i) {
+                       ir_node *op = get_irn_n(irn, i);
+                       if(arch_irn_consider_in_reg_alloc(aenv, cls, op)
+                               && !values_interfere(env->birg, op, last_proj)) {
+                               frontier = sched_next(irn);
+                               goto found_front;
+                       }
+               }
+       }
+found_front:
+
+       DBG((mod, LEVEL_2, "\tfrontier: %+F\n", frontier));
+
+       node = sched_prev(perm);
+       n_moved = 0;
+       while(!sched_is_begin(node)) {
+               int      input = -1;
+               ir_node *proj;
+
+               foreach_out_edge(perm, edge) {
+                       ir_node *out = get_edge_src_irn(edge);
+                       int      pn  = get_Proj_proj(out);
+                       ir_node *in  = get_irn_n(perm, pn);
+                       if(node == in) {
+                               proj  = out;
+                               input = pn;
+                               break;
+                       }
+               }
+               /* it wasn't an input to the perm, we can't do anything more */
+               if(input < 0)
+                       break;
+               if(!sched_comes_after(frontier, node))
+                       break;
+               if(arch_irn_is(aenv, node, modify_flags))
+                       break;
+               for(i = get_irn_arity(node) - 1; i >= 0; --i) {
+                       ir_node *opop = get_irn_n(node, i);
+                       if (arch_irn_consider_in_reg_alloc(aenv, cls, opop)) {
+                               break;
+                       }
+               }
+               if(i >= 0)
+                       break;
+
+               DBG((mod, LEVEL_2, "\tmoving %+F after %+F, killing %+F\n", node, perm, proj));
+
+               /* move the movable node in front of the Perm */
+               sched_remove(node);
+               sched_add_after(perm, node);
+
+               /* give it the proj's register */
+               arch_set_irn_register(aenv, node, arch_get_irn_register(aenv, proj));
+
+               /* reroute all users of the proj to the moved node. */
+               edges_reroute(proj, node, irg);
+
+               /* and kill it */
+               set_Proj_pred(proj, new_Bad());
+               be_kill_node(proj);
+
+               bitset_set(moved, input);
+               n_moved++;
+
+               node = sched_prev(node);
+       }
+
+       /* well, we could not push anything through the perm */
+       if(n_moved == 0)
+               return 1;
+
+       new_size = arity - n_moved;
+       if(new_size == 0) {
+               return 0;
+       }
+
+       map      = alloca(new_size * sizeof(map[0]));
+       proj_map = alloca(arity * sizeof(proj_map[0]));
+       memset(proj_map, -1, sizeof(proj_map[0]));
+       n   = 0;
+       for(i = 0; i < arity; ++i) {
+               if(bitset_is_set(moved, i))
+                       continue;
+               map[n]      = i;
+               proj_map[i] = n;
+               n++;
+       }
+       assert(n == new_size);
+       foreach_out_edge(perm, edge) {
+               ir_node *proj = get_edge_src_irn(edge);
+               int      pn   = get_Proj_proj(proj);
+               pn = proj_map[pn];
+               assert(pn >= 0);
+               set_Proj_proj(proj, pn);
+       }
+
+       be_Perm_reduce(perm, new_size, map);
+       return 1;
+}
 
 /**
  * Calls the corresponding lowering function for the node.
@@ -885,13 +1020,18 @@ void assure_constraints(be_irg_t *birg) {
  * @param walk_env The walker environment
  */
 static void lower_nodes_after_ra_walker(ir_node *irn, void *walk_env) {
-       if (! is_Block(irn) && ! is_Proj(irn)) {
-               if (be_is_Perm(irn)) {
-                       lower_perm_node(irn, walk_env);
-               }
-       }
+       int perm_stayed;
 
-       return;
+       if (is_Block(irn) || is_Proj(irn))
+               return;
+       if (!be_is_Perm(irn))
+               return;
+
+       perm_stayed = push_through_perm(irn, walk_env);
+       if (!perm_stayed)
+               return;
+
+       lower_perm_node(irn, walk_env);
 }
 
 /**
@@ -910,5 +1050,8 @@ void lower_nodes_after_ra(be_irg_t *birg, int do_copy) {
        env.do_copy  = do_copy;
        FIRM_DBG_REGISTER(env.dbg_module, "firm.be.lower");
 
+       /* we will need interference */
+       be_liveness_assure_chk(be_get_birg_liveness(birg));
+
        irg_walk_blkwise_graph(irg, NULL, lower_nodes_after_ra_walker, &env);
 }