/*
- * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved.
+ * Copyright (C) 1995-2011 University of Karlsruhe. All right reserved.
*
* This file is part of libFirm.
*
* @brief Methods to compute when a value will be used again.
* @author Sebastian Hack, Matthias Braun
* @date 27.06.2005
- * @version $Id$
*/
#include "config.h"
#include "irgraph_t.h"
#include "iredges_t.h"
#include "irdom_t.h"
+#include "util.h"
#include "be_t.h"
#include "beutil.h"
#include "bearch.h"
#include "beuses.h"
-#define SCAN_INTERBLOCK_USES
+#define UNKNOWN_OUTERMOST_LOOP ((unsigned)-1)
-typedef struct _be_use_t {
+typedef struct be_use_t {
const ir_node *block;
const ir_node *node;
- int outermost_loop;
+ unsigned outermost_loop;
unsigned next_use;
- unsigned visited;
+ ir_visited_t visited;
} be_use_t;
-struct _be_uses_t {
- set *uses;
- ir_graph *irg;
- const be_lv_t *lv;
- unsigned visited_counter;
- DEBUG_ONLY(firm_dbg_module_t *dbg;)
+/**
+ * The "uses" environment.
+ */
+struct be_uses_t {
+ set *uses; /**< cache: contains all computed uses so far. */
+ ir_graph *irg; /**< the graph for this environment. */
+ const be_lv_t *lv; /**< the liveness for the graph. */
+ ir_visited_t visited_counter; /**< current search counter. */
+ DEBUG_ONLY(firm_dbg_module_t *dbg; /**< debug module for debug messages. */)
};
+/**
+ * Set-compare two uses.
+ */
static int cmp_use(const void *a, const void *b, size_t n)
{
- const be_use_t *p = a;
- const be_use_t *q = b;
+ const be_use_t *p = (const be_use_t*)a;
+ const be_use_t *q = (const be_use_t*)b;
(void) n;
return !(p->block == q->block && p->node == q->node);
}
static be_next_use_t get_next_use(be_uses_t *env, ir_node *from,
- unsigned from_step, const ir_node *def,
- int skip_from_uses);
+ const ir_node *def, int skip_from_uses);
+/**
+ * Return the use for the given definition in the given block if exists,
+ * else create it.
+ *
+ * @param env the uses environment
+ * @param block the block we search the use in
+ * @param def the definition of the value we are searching
+ */
static const be_use_t *get_or_set_use_block(be_uses_t *env,
const ir_node *block,
const ir_node *def)
{
- unsigned hash = HASH_COMBINE(hash_irn(block), hash_irn(def));
+ unsigned hash = hash_combine(hash_irn(block), hash_irn(def));
be_use_t temp;
be_use_t* result;
temp.block = block;
temp.node = def;
- result = set_find(env->uses, &temp, sizeof(temp), hash);
+ result = set_find(be_use_t, env->uses, &temp, sizeof(temp), hash);
if (result == NULL) {
// insert templ first as we might end in a loop in the get_next_use
// call otherwise
temp.next_use = USES_INFINITY;
- temp.outermost_loop = -1;
+ temp.outermost_loop = UNKNOWN_OUTERMOST_LOOP;
temp.visited = 0;
- result = set_insert(env->uses, &temp, sizeof(temp), hash);
+ result = set_insert(be_use_t, env->uses, &temp, sizeof(temp), hash);
}
- if (result->outermost_loop < 0 && result->visited < env->visited_counter) {
+ if (result->outermost_loop == UNKNOWN_OUTERMOST_LOOP && result->visited < env->visited_counter) {
be_next_use_t next_use;
result->visited = env->visited_counter;
- next_use = get_next_use(env, sched_first(block), 0, def, 0);
- if (next_use.outermost_loop >= 0) {
+ next_use = get_next_use(env, sched_first(block), def, 0);
+ if (next_use.outermost_loop != UNKNOWN_OUTERMOST_LOOP) {
result->next_use = next_use.time;
result->outermost_loop = next_use.outermost_loop;
- DBG((env->dbg, LEVEL_5, "Setting nextuse of %+F in block %+F to %u (outermostloop %d)\n", def, block, result->next_use, result->outermost_loop));
+ DBG((env->dbg, LEVEL_5, "Setting nextuse of %+F in block %+F to %u (outermostloop %d)\n",
+ def, block, result->next_use, result->outermost_loop));
}
}
return result;
}
+/**
+ * Check if a value of the given definition is used in the given block
+ * as a Phi argument.
+ *
+ * @param block the block to check
+ * @param def the definition of the value
+ *
+ * @return non-zero if the value is used in the given block as a Phi argument
+ * in one of its successor blocks.
+ */
static int be_is_phi_argument(const ir_node *block, const ir_node *def)
{
- ir_node *node;
- ir_node *succ_block = NULL;
- const ir_edge_t *edge;
- int arity, i;
-
#if 1
if (get_irn_n_edges_kind(block, EDGE_KIND_BLOCK) < 1)
#else
#endif
return 0;
- foreach_block_succ(block, edge) {
- succ_block = get_edge_src_irn(edge);
- break;
- }
+ ir_node *const succ_block = get_first_block_succ(block);
- arity = get_Block_n_cfgpreds(succ_block);
- if (arity <= 1)
+ if (get_Block_n_cfgpreds(succ_block) <= 1) {
+ /* no Phis in the successor */
return 0;
-
- for (i = 0; i < arity; ++i) {
- if (get_Block_cfgpred_block(succ_block, i) == block)
- break;
}
- assert(i < arity);
+ /* find the index of block in its successor */
+ int const i = get_Block_cfgpred_pos(succ_block, block);
+ assert(i >= 0);
+
+ /* iterate over the Phi nodes in the successor and check if def is
+ * one of its arguments */
sched_foreach(succ_block, node) {
ir_node *arg;
- if (!is_Phi(node))
+ if (!is_Phi(node)) {
+ /* found first non-Phi node, we can stop the search here */
break;
+ }
arg = get_irn_n(node, i);
if (arg == def)
return 0;
}
-static inline
-unsigned get_step(const ir_node *node)
+/**
+ * Retrieve the scheduled index (the "step") of this node in its
+ * block.
+ *
+ * @param node the node
+ */
+static inline unsigned get_step(const ir_node *node)
+{
+ return (unsigned)PTR_TO_INT(get_irn_link(node));
+}
+
+/**
+ * Set the scheduled index (the "step") of this node in its
+ * block.
+ *
+ * @param node the node
+ * @param step the scheduled index of the node
+ */
+static inline void set_step(ir_node *node, unsigned step)
{
- return PTR_TO_INT(get_irn_link(node));
+ set_irn_link(node, INT_TO_PTR(step));
}
+/**
+ * Find the next use of a value defined by def, starting at node from.
+ *
+ * @param env the uses environment
+ * @param from the node at which we should start the search
+ * @param def the definition of the value
+ * @param skip_from_uses if non-zero, ignore from uses
+ */
static be_next_use_t get_next_use(be_uses_t *env, ir_node *from,
- unsigned from_step, const ir_node *def,
- int skip_from_uses)
+ const ir_node *def, int skip_from_uses)
{
- unsigned step = from_step;
+ unsigned step;
ir_node *block = get_nodes_block(from);
- ir_node *next_use;
+ ir_node *next_use_node;
ir_node *node;
unsigned timestep;
unsigned next_use_step;
- const ir_edge_t *edge;
-#if 1
assert(skip_from_uses == 0 || skip_from_uses == 1);
if (skip_from_uses) {
from = sched_next(from);
}
- next_use = NULL;
+ next_use_node = NULL;
next_use_step = INT_MAX;
timestep = get_step(from);
foreach_out_edge(def, edge) {
- ir_node *node = get_edge_src_irn(edge);
- unsigned node_step;
+ unsigned node_step;
+ node = get_edge_src_irn(edge);
if (is_Anchor(node))
continue;
if (node_step < timestep)
continue;
if (node_step < next_use_step) {
- next_use = node;
+ next_use_node = node;
next_use_step = node_step;
}
}
- if (next_use != NULL) {
+ if (next_use_node != NULL) {
be_next_use_t result;
result.time = next_use_step - timestep + skip_from_uses;
result.outermost_loop = get_loop_depth(get_irn_loop(block));
- result.before = next_use;
+ result.before = next_use_node;
return result;
}
node = sched_last(block);
step = get_step(node) + 1 + timestep + skip_from_uses;
-#else
- if (skip_from_uses) {
- from = sched_next(from);
- ++step;
- }
-
- sched_foreach_from(from, node) {
- int i, arity;
-
- if (is_Phi(node)) {
- step++;
- continue;
- }
-
- arity = get_irn_arity(node);
- for (i = 0; i < arity; ++i) {
- const ir_node *operand = get_irn_n(node, i);
-
- if (operand == def) {
- be_next_use_t result;
-
- DBG((env->dbg, LEVEL_3, "found use of %+F at %+F\n", operand, node));
-
- /**
- * Spills/Reloads are a special case, they're not really a
- * usage of a value, continue searching
- */
- if (be_is_Spill(node) || be_is_Reload(node)) {
- return be_get_next_use(env, node, step, node, 1);
- }
-
- result.time = step;
- result.outermost_loop = get_loop_depth(get_irn_loop(block));
- result.before = node;
- return result;
- }
- }
-
- step++;
- }
-#endif
-
if (be_is_phi_argument(block, def)) {
// TODO we really should continue searching the uses of the phi,
// as a phi isn't a real use that implies a reload (because we could
return result;
}
-#ifdef SCAN_INTERBLOCK_USES
{
- unsigned next_use = USES_INFINITY;
- int outermost_loop;
+ unsigned next_use = USES_INFINITY;
+ unsigned outermost_loop;
be_next_use_t result;
- ir_loop *loop = get_irn_loop(block);
- int loopdepth = get_loop_depth(loop);
- int found_visited = 0;
- int found_use = 0;
- ir_graph *irg = get_irn_irg(block);
- ir_node *startblock = get_irg_start_block(irg);
+ ir_loop *loop = get_irn_loop(block);
+ unsigned loopdepth = get_loop_depth(loop);
+ int found_visited = 0;
+ int found_use = 0;
+ ir_graph *irg = get_irn_irg(block);
+ ir_node *startblock = get_irg_start_block(irg);
result.before = NULL;
outermost_loop = loopdepth;
}
use = get_or_set_use_block(env, succ_block, def);
- DBG((env->dbg, LEVEL_5, "Found %u (loopdepth %d) (we're in block %+F)\n", use->next_use,
+ DBG((env->dbg, LEVEL_5, "Found %u (loopdepth %u) (we're in block %+F)\n", use->next_use,
use->outermost_loop, block));
if (USES_IS_INFINITE(use->next_use)) {
- if (use->outermost_loop < 0) {
+ if (use->outermost_loop == UNKNOWN_OUTERMOST_LOOP) {
found_visited = 1;
}
continue;
if (!found_use && found_visited) {
// the current result is correct for the current search, but isn't
// generally correct, so mark it
- result.outermost_loop = -1;
+ result.outermost_loop = UNKNOWN_OUTERMOST_LOOP;
}
- DBG((env->dbg, LEVEL_5, "Result: %d (outerloop: %d)\n", result.time, result.outermost_loop));
+ DBG((env->dbg, LEVEL_5, "Result: %d (outerloop: %u)\n", result.time, result.outermost_loop));
return result;
}
-#else
- return USES_INFINITY;
-#endif
}
be_next_use_t be_get_next_use(be_uses_t *env, ir_node *from,
- unsigned from_step, const ir_node *def,
- int skip_from_uses)
+ const ir_node *def, int skip_from_uses)
{
- env->visited_counter++;
- return get_next_use(env, from, from_step, def, skip_from_uses);
+ ++env->visited_counter;
+ return get_next_use(env, from, def, skip_from_uses);
}
-static
-void set_sched_step_walker(ir_node *block, void *data)
+/**
+ * Pre-block walker, set the step number for every scheduled node
+ * in increasing order.
+ *
+ * After this, two scheduled nodes can be easily compared for the
+ * "scheduled earlier in block" property.
+ */
+static void set_sched_step_walker(ir_node *block, void *data)
{
- ir_node *node;
unsigned step = 0;
(void) data;
sched_foreach(block, node) {
- set_irn_link(node, INT_TO_PTR(step));
+ set_step(node, step);
if (is_Phi(node))
continue;
++step;
{
be_uses_t *env = XMALLOC(be_uses_t);
- edges_assure(irg);
+ assure_edges(irg);
//set_using_irn_link(irg);
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