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authorMichael Beck <beck@ipd.info.uni-karlsruhe.de>2011-02-06 16:05:57 +0100
committerMichael Beck <beck@ipd.info.uni-karlsruhe.de>2011-02-06 16:05:57 +0100
commitfe43982e128771c98ee2b2d4fcc77881e72080e5 (patch)
treedfafa77206b9ad6ab26360074e5c930590c0b890 /ir/be/beuses.c
parent08afd0c691c7f2c385a6ba0d3b3ce7c8891a0978 (diff)
Removed unused parameter from_step of be_get_next_use().
Additionally - switched the type of a visitor counter to ir_visited_t - add some doxygen docu [r28328]
Diffstat (limited to 'ir/be/beuses.c')
-rw-r--r--ir/be/beuses.c77
1 files changed, 57 insertions, 20 deletions
diff --git a/ir/be/beuses.c b/ir/be/beuses.c
index 57453e9..40849ae 100644
--- a/ir/be/beuses.c
+++ b/ir/be/beuses.c
@@ -1,5 +1,5 @@
/*
- * 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.
*
@@ -55,17 +55,23 @@ typedef struct be_use_t {
const ir_node *node;
int outermost_loop;
unsigned next_use;
- unsigned visited;
+ ir_visited_t visited;
} be_use_t;
+/**
+ * The "uses" environment.
+ */
struct be_uses_t {
- set *uses;
- ir_graph *irg;
- const be_lv_t *lv;
- unsigned visited_counter;
- DEBUG_ONLY(firm_dbg_module_t *dbg;)
+ 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 = (const be_use_t*)a;
@@ -76,9 +82,16 @@ static int cmp_use(const void *a, const void *b, size_t n)
}
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)
@@ -104,17 +117,28 @@ static const be_use_t *get_or_set_use_block(be_uses_t *env,
be_next_use_t next_use;
result->visited = env->visited_counter;
- next_use = get_next_use(env, sched_first(block), 0, def, 0);
+ next_use = get_next_use(env, sched_first(block), def, 0);
if (next_use.outermost_loop >= 0) {
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;
@@ -131,20 +155,27 @@ static int be_is_phi_argument(const ir_node *block, const ir_node *def)
succ_block = get_first_block_succ(block);
arity = get_Block_n_cfgpreds(succ_block);
- if (arity <= 1)
+ if (arity <= 1) {
+ /* no Phis in the successor */
return 0;
+ }
+ /* find the index of block in its successor */
for (i = 0; i < arity; ++i) {
if (get_Block_cfgpred_block(succ_block, i) == block)
break;
}
assert(i < arity);
+ /* 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)
@@ -177,11 +208,18 @@ static inline void set_step(ir_node *node, unsigned step)
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 *node;
@@ -314,11 +352,10 @@ static be_next_use_t get_next_use(be_uses_t *env, ir_node *from,
}
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);
}
/**