check register pressure in loops for variables, selected for spilling due to loop...

diff --git a/ir/be/bespillbelady.c b/ir/be/bespillbelady.c
index 8710ccc..dac32ee 100644 (file)
--- a/ir/be/bespillbelady.c
+++ b/ir/be/bespillbelady.c
@@ -40,6 +40,7 @@
 #include "benode_t.h"
 #include "bechordal_t.h"
 #include "bespilloptions.h"
+#include "beloopana.h"
 
 #define DBG_SPILL   1
 #define DBG_WSETS   2
@@ -69,6 +70,7 @@ typedef struct _belady_env_t {
        const arch_env_t *arch;
        const arch_register_class_t *cls;
        const be_lv_t *lv;
+       be_loopana_t *loop_ana;
        int n_regs;                     /** number of regs in this reg-class */
 
        workset_t *ws;          /**< the main workset used while processing a block. ob-allocated */
@@ -372,13 +374,11 @@ static loc_t to_take_or_not_to_take(belady_env_t *env, ir_node* first, ir_node *
 
        if(next_use.outermost_loop >= get_loop_depth(loop)) {
                DBG((dbg, DBG_START, "    %+F taken (%u, loop %d)\n", node, loc.time, next_use.outermost_loop));
-               return loc;
-               // ARR_APP1(loc_t, starters, loc);
        } else {
-               loc.time = USES_INFINITY;
-               DBG((dbg, DBG_START, "    %+F not taken (outerloopdepth %d < loopdetph %d)\n", node, next_use.outermost_loop, get_loop_depth(loop)));
-               return loc;
+               loc.time = USES_PENDING;
+               DBG((dbg, DBG_START, "    %+F delayed (outerloopdepth %d < loopdetph %d)\n", node, next_use.outermost_loop, get_loop_depth(loop)));
        }
+       return loc;
 }
 
 /*
@@ -386,15 +386,17 @@ static loc_t to_take_or_not_to_take(belady_env_t *env, ir_node* first, ir_node *
  * and notifies spill algorithm which phis need to be spilled
  */
 static void compute_live_ins(ir_node *block, void *data) {
-       belady_env_t *env = data;
-       block_info_t *block_info;
-       ir_node *first, *irn;
-       loc_t loc, *starters;
-       int i, len, ws_count;
-       ir_loop *loop = get_irn_loop(block);
-       const be_lv_t *lv = env->lv;
-
-       if(get_Block_n_cfgpreds(block) == 1 && get_irg_start_block(get_irn_irg(block)) != block)
+       belady_env_t  *env  = data;
+       ir_loop       *loop = get_irn_loop(block);
+       const be_lv_t *lv   = env->lv;
+       block_info_t  *block_info;
+       ir_node       *first, *irn;
+       loc_t         loc, *starters, *delayed;
+       int           i, len, ws_count;
+       int               free_slots, free_pressure_slots;
+       unsigned      pressure;
+
+       if (get_Block_n_cfgpreds(block) == 1 && get_irg_start_block(get_irn_irg(block)) != block)
                return;
 
        block_info = new_block_info(&env->ob);
@@ -402,38 +404,58 @@ static void compute_live_ins(ir_node *block, void *data) {
 
        /* Collect all values living at start of block */
        starters = NEW_ARR_F(loc_t, 0);
+       delayed  = NEW_ARR_F(loc_t, 0);
 
        DBG((dbg, DBG_START, "Living at start of %+F:\n", block));
        first = sched_first(block);
 
+       /* check all Phis first */
        sched_foreach(block, irn) {
-               if(!is_Phi(irn))
+               if (! is_Phi(irn))
                        break;
 
                loc = to_take_or_not_to_take(env, first, irn, block, loop);
 
-               if(!USES_IS_INFINITE(loc.time)) {
-                       ARR_APP1(loc_t, starters, loc);
+               if (! USES_IS_INFINITE(loc.time)) {
+                       if (USES_IS_PENDING(loc.time))
+                               ARR_APP1(loc_t, delayed, loc);
+                       else
+                               ARR_APP1(loc_t, starters, loc);
                } else {
                        be_spill_phi(env->senv, irn);
                }
        }
 
+       /* check all Live-Ins */
        be_lv_foreach(lv, block, be_lv_state_in, i) {
                ir_node *node = be_lv_get_irn(lv, block, i);
 
                loc = to_take_or_not_to_take(env, first, node, block, loop);
 
-               if(!USES_IS_INFINITE(loc.time)) {
-                       ARR_APP1(loc_t, starters, loc);
+               if (! USES_IS_INFINITE(loc.time)) {
+                       if (USES_IS_PENDING(loc.time))
+                               ARR_APP1(loc_t, delayed, loc);
+                       else
+                               ARR_APP1(loc_t, starters, loc);
                }
        }
 
-       // Sort start values by first use
+       pressure            = be_get_loop_pressure(env->loop_ana, env->cls, loop);
+       free_slots          = env->n_regs - ARR_LEN(starters);
+       free_pressure_slots = env->n_regs - pressure;
+       free_slots          = MIN(free_slots, free_pressure_slots);
+       /* append nodes delayed due to loop structure until start set is full */
+       for (i = 0; i < ARR_LEN(delayed) && i < free_slots; ++i) {
+               DBG((dbg, DBG_START, "    delayed %+F taken\n", delayed[i].irn));
+               ARR_APP1(loc_t, starters, delayed[i]);
+       }
+       DEL_ARR_F(delayed);
+
+       /* Sort start values by first use */
        qsort(starters, ARR_LEN(starters), sizeof(starters[0]), loc_compare);
 
        /* Copy the best ones from starters to start workset */
-       ws_count = MIN(ARR_LEN(starters), env->n_regs);
+       ws_count             = MIN(ARR_LEN(starters), env->n_regs);
        block_info->ws_start = new_workset(env, &env->ob);
        workset_bulk_fill(block_info->ws_start, ws_count, starters);
 
@@ -441,7 +463,7 @@ static void compute_live_ins(ir_node *block, void *data) {
        len = ARR_LEN(starters);
        for (i = ws_count; i < len; ++i) {
                irn = starters[i].irn;
-               if (!is_Phi(irn) || get_nodes_block(irn) != block)
+               if (! is_Phi(irn) || get_nodes_block(irn) != block)
                        continue;
 
                be_spill_phi(env->senv, irn);
@@ -654,6 +676,7 @@ void be_spill_belady_spill_env(be_irg_t *birg, const arch_register_class_t *cls,
        env.n_regs    = env.cls->n_regs - be_put_ignore_regs(birg, cls, NULL);
        env.ws        = new_workset(&env, &env.ob);
        env.uses      = be_begin_uses(irg, env.lv);
+       env.loop_ana  = be_new_loop_pressure(birg);
        if(spill_env == NULL) {
                env.senv = be_new_spill_env(birg);
        } else {
@@ -675,6 +698,7 @@ void be_spill_belady_spill_env(be_irg_t *birg, const arch_register_class_t *cls,
        if(spill_env == NULL)
                be_delete_spill_env(env.senv);
        be_end_uses(env.uses);
+       be_free_loop_pressure(env.loop_ana);
        obstack_free(&env.ob, NULL);
 }