/*
- * Copyright (C) 1995-2007 University of Karlsruhe. All right reserved.
+ * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved.
*
* This file is part of libFirm.
*
#include "beutil.h"
#include "bearch_t.h"
-#include "bespillbelady.h"
#include "beuses.h"
#include "besched_t.h"
#include "beirgmod.h"
#include "bespilloptions.h"
#include "beloopana.h"
#include "beirg_t.h"
+#include "bespill.h"
#include "bemodule.h"
#define DBG_SPILL 1
#define DBG_WORKSET 128
DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
+/* factor to weight the different costs of reloading/rematerializing a node
+ (see bespill.h be_get_reload_costs_no_weight) */
+#define RELOAD_COST_FACTOR 10
+
typedef enum {
value_not_reloaded, /* the value has not been reloaded */
value_partially_reloaded, /* the value has been reloaded on some paths */
{
be_next_use_t use;
int flags = arch_irn_get_flags(arch_env, def);
+ unsigned costs;
unsigned time;
assert(! (flags & arch_irn_flags_ignore));
if(flags & arch_irn_flags_dont_spill)
return 0;
- time = use.time;
- time += be_get_reload_costs_no_weight(senv, def, use.before) * 10;
+ costs = be_get_reload_costs_no_weight(senv, def, use.before);
+ assert(costs * RELOAD_COST_FACTOR < 1000);
+ time = use.time + 1000 - (costs * RELOAD_COST_FACTOR);
- return use.time;
+ return time;
}
/**
*/
static void displace(workset_t *new_vals, int is_usage)
{
- ir_node *val;
- int i, len, max_allowed, demand, iter;
-
- ir_node **to_insert = alloca(n_regs * sizeof(to_insert[0]));
-
- /*
- 1. Identify the number of needed slots and the values to reload
- */
+ ir_node **to_insert = alloca(n_regs * sizeof(to_insert[0]));
+ ir_node *val;
+ int i;
+ int len;
+ int spills_needed;
+ int demand;
+ int iter;
+
+ /* 1. Identify the number of needed slots and the values to reload */
demand = 0;
workset_foreach(new_vals, val, iter) {
/* mark value as used */
ir_nodeset_insert(&used, val);
if (! workset_contains(ws, val)) {
- DBG((dbg, DBG_DECIDE, " insert %+F\n", val));
- to_insert[demand++] = val;
+ DB((dbg, DBG_DECIDE, " insert %+F\n", val));
if (is_usage) {
- DBG((dbg, DBG_SPILL, "Reload %+F before %+F\n", val, instr));
+ DB((dbg, DBG_SPILL, "Reload %+F before %+F\n", val, instr));
be_add_reload(senv, val, instr, cls, 1);
}
} else {
- DBG((dbg, DBG_DECIDE, " %+F already in workset\n", val));
+ DB((dbg, DBG_DECIDE, " %+F already in workset\n", val));
assert(is_usage);
+ /* remove the value from the current workset so it is not accidently
+ * spilled */
+ workset_remove(ws, val);
}
+ to_insert[demand++] = val;
}
- /*
- 2. Make room for at least 'demand' slots
- */
- len = workset_get_length(ws);
- max_allowed = n_regs - demand;
+ /* 2. Make room for at least 'demand' slots */
+ len = workset_get_length(ws);
+ spills_needed = len + demand - n_regs;
+ assert(spills_needed <= len);
/* Only make more free room if we do not have enough */
- if (len > max_allowed) {
- DBG((dbg, DBG_DECIDE, " disposing %d values\n",
- ws->len - max_allowed));
+ if (spills_needed > 0) {
+ ir_node *curr_bb = get_nodes_block(instr);
+ workset_t *ws_start = get_block_info(curr_bb)->start_workset;
+
+ DB((dbg, DBG_DECIDE, " disposing %d values\n", spills_needed));
- /* get current next-use distance */
- for (i = 0; i < ws->len; ++i) {
+ /* calculate current next-use distance for live values */
+ for (i = 0; i < len; ++i) {
ir_node *val = workset_get_val(ws, i);
unsigned dist = get_distance(instr, instr_nr, val, !is_usage);
workset_set_time(ws, i, dist);
/* sort entries by increasing nextuse-distance*/
workset_sort(ws);
- /*
- Logic for not needed live-ins: If a value is disposed
- before its first usage, remove it from start workset
- We don't do this for phis though
- */
- for (i = max_allowed; i < ws->len; ++i) {
- ir_node *node = ws->vals[i].node;
+ /* Logic for not needed live-ins: If a value is disposed
+ * before its first usage, remove it from start workset
+ * We don't do this for phis though */
+ for (i = len - spills_needed; i < len; ++i) {
+ ir_node *val = ws->vals[i].node;
- DBG((dbg, DBG_DECIDE, " disposing node %+F (%u)\n", node,
+ DB((dbg, DBG_DECIDE, " disposing node %+F (%u)\n", val,
workset_get_time(ws, i)));
if(!USES_IS_INFINITE(ws->vals[i].time)
&& !ws->vals[i].reloaded) {
- //be_add_spill(senv, node, instr);
+ //be_add_spill(senv, val, instr);
}
- if (is_Phi(node))
- continue;
-
- if (! ir_nodeset_contains(&used, node)) {
- ir_node *curr_bb = get_nodes_block(instr);
- workset_t *ws_start = get_block_info(curr_bb)->start_workset;
- workset_remove(ws_start, node);
-
- DBG((dbg, DBG_DECIDE, " (and removing %+F from start workset)\n", node));
+ if (!is_Phi(val) && ! ir_nodeset_contains(&used, val)) {
+ workset_remove(ws_start, val);
+ DB((dbg, DBG_DECIDE, " (and removing %+F from start workset)\n", val));
}
}
/* kill the last 'demand' entries in the array */
- workset_set_length(ws, max_allowed);
+ workset_set_length(ws, len - spills_needed);
}
- /*
- 3. Insert the new values into the workset
- */
- for (i = 0; i < demand; ++i)
- workset_insert(ws, to_insert[i], 1);
+ /* 3. Insert the new values into the workset */
+ for (i = 0; i < demand; ++i) {
+ ir_node *val = to_insert[i];
+
+ workset_insert(ws, val, 1);
+ }
}
/** Decides whether a specific node should be in the start workset or not
/* We have to keep nonspillable nodes in the workingset */
if(arch_irn_get_flags(arch_env, node) & arch_irn_flags_dont_spill) {
loc.time = 0;
- DBG((dbg, DBG_START, " %+F taken (dontspill node)\n", node, loc.time));
+ DB((dbg, DBG_START, " %+F taken (dontspill node)\n", node, loc.time));
return loc;
}
// the nodes marked as live in shouldn't be dead, so it must be a phi
assert(is_Phi(node));
loc.time = USES_INFINITY;
- DBG((dbg, DBG_START, " %+F not taken (dead)\n", node));
+ DB((dbg, DBG_START, " %+F not taken (dead)\n", node));
if(is_Phi(node)) {
be_spill_phi(senv, node);
}
loc.time = next_use.time;
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));
+ DB((dbg, DBG_START, " %+F taken (%u, loop %d)\n", node, loc.time,
+ next_use.outermost_loop));
} else {
loc.time = USES_PENDING;
- DBG((dbg, DBG_START, " %+F delayed (outerloopdepth %d < loopdetph %d)\n", node, next_use.outermost_loop, get_loop_depth(loop)));
+ DB((dbg, DBG_START, " %+F delayed (outerdepth %d < loopdepth %d)\n",
+ node, next_use.outermost_loop, get_loop_depth(loop)));
}
return loc;
}
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));
+ DB((dbg, DBG_START, "Living at start of %+F:\n", block));
first = sched_first(block);
/* check all Phis first */
/* so far we only put nodes into the starters list that are used inside
* the loop. If register pressure in the loop is low then we can take some
* values and let them live through the loop */
- if(free_slots > 0) {
+ if (free_slots > 0) {
qsort(delayed, ARR_LEN(delayed), sizeof(delayed[0]), loc_compare);
for (i = 0; i < ARR_LEN(delayed) && i < free_slots; ++i) {
- DBG((dbg, DBG_START, " delayed %+F taken\n", delayed[i].node));
- ARR_APP1(loc_t, starters, delayed[i]);
- delayed[i].node = NULL;
+ int p, arity;
+ loc_t *loc = & delayed[i];
+
+ /* don't use values which are dead in a known predecessors
+ * to not induce unnecessary reloads */
+ arity = get_irn_arity(block);
+ for (p = 0; p < arity; ++p) {
+ ir_node *pred_block = get_Block_cfgpred_block(block, p);
+ block_info_t *pred_info = get_block_info(pred_block);
+
+ if (pred_info == NULL)
+ continue;
+
+ if (!workset_contains(pred_info->end_workset, loc->node)) {
+ DB((dbg, DBG_START,
+ " delayed %+F not live at pred %+F\n", loc->node,
+ pred_block));
+ goto skip_delayed;
+ }
+ }
+
+ DB((dbg, DBG_START, " delayed %+F taken\n", loc->node));
+ ARR_APP1(loc_t, starters, *loc);
+ loc->node = NULL;
+ skip_delayed:
+ ;
}
}
if(node == NULL || !is_Phi(node) || get_nodes_block(node) != block)
continue;
- DBG((dbg, DBG_START, " spilling delayed phi %+F\n", node));
+ DB((dbg, DBG_START, " spilling delayed phi %+F\n", node));
be_spill_phi(senv, node);
}
DEL_ARR_F(delayed);
if (! is_Phi(node) || get_nodes_block(node) != block)
continue;
- DBG((dbg, DBG_START, " spilling phi %+F\n", node));
+ DB((dbg, DBG_START, " spilling phi %+F\n", node));
be_spill_phi(senv, node);
}
compute_live_ins(block);
}
- DBG((dbg, DBG_DECIDE, "\n"));
- DBG((dbg, DBG_DECIDE, "Decide for %+F\n", block));
+ DB((dbg, DBG_DECIDE, "\n"));
+ DB((dbg, DBG_DECIDE, "Decide for %+F\n", block));
block_info = new_block_info();
set_block_info(block, block_info);
- DBG((dbg, DBG_WSETS, "Start workset for %+F:\n", block));
+ DB((dbg, DBG_WSETS, "Start workset for %+F:\n", block));
workset_foreach(ws, irn, iter) {
- DBG((dbg, DBG_WSETS, " %+F (%u)\n", irn,
+ DB((dbg, DBG_WSETS, " %+F (%u)\n", irn,
workset_get_time(ws, iter)));
}
block_info->start_workset = workset_clone(ws);
/* process the block from start to end */
- DBG((dbg, DBG_WSETS, "Processing...\n"));
+ DB((dbg, DBG_WSETS, "Processing...\n"));
ir_nodeset_init(&used);
instr_nr = 0;
/* TODO: this leaks (into the obstack)... */
if (is_Phi(irn)) {
continue;
}
- DBG((dbg, DBG_DECIDE, " ...%+F\n", irn));
+ DB((dbg, DBG_DECIDE, " ...%+F\n", irn));
/* set instruction in the workset */
instr = irn;
/* Remember end-workset for this block */
block_info->end_workset = workset_clone(ws);
- DBG((dbg, DBG_WSETS, "End workset for %+F:\n", block));
+ DB((dbg, DBG_WSETS, "End workset for %+F:\n", block));
workset_foreach(ws, irn, iter)
- DBG((dbg, DBG_WSETS, " %+F (%u)\n", irn,
+ DB((dbg, DBG_WSETS, " %+F (%u)\n", irn,
workset_get_time(ws, iter)));
/* add successor blocks into worklist */
int iter;
(void) data;
- DBG((dbg, DBG_FIX, "\n"));
- DBG((dbg, DBG_FIX, "Fixing %+F\n", block));
+ DB((dbg, DBG_FIX, "\n"));
+ DB((dbg, DBG_FIX, "Fixing %+F\n", block));
start_workset = get_block_info(block)->start_workset;
workset_t *pred_end_workset = get_block_info(pred)->end_workset;
ir_node *node;
- DBG((dbg, DBG_FIX, " Pred %+F\n", pred));
+ DB((dbg, DBG_FIX, " Pred %+F\n", pred));
/* spill all values not used anymore */
workset_foreach(pred_end_workset, node, iter) {
&& !pred_end_workset->vals[iter].reloaded) {
ir_node *insert_point
= be_get_end_of_block_insertion_point(pred);
- DBG((dbg, DBG_SPILL, "Spill %+F before %+F\n", node,
+ DB((dbg, DBG_SPILL, "Spill %+F before %+F\n", node,
insert_point));
be_add_spill(senv, node, insert_point);
}
continue;
/* node is not in memory at the end of pred -> reload it */
- DBG((dbg, DBG_FIX, " reload %+F\n", node));
- DBG((dbg, DBG_SPILL, "Reload %+F before %+F,%d\n", node, block, i));
+ DB((dbg, DBG_FIX, " reload %+F\n", node));
+ DB((dbg, DBG_SPILL, "Reload %+F before %+F,%d\n", node, block, i));
be_add_reload_on_edge(senv, node, block, i, cls, 1);
}
}
projects / libfirm / blobdiff