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Commit 4fc85bd4 authored by Michael Beck's avatar Michael Beck
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- add some doxygen comments laying around 

[r26179]
parent 5c1ded54
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Inline Side-by-side
ir/be/benewalloc.c
View file @ 4fc85bd4
......@@ -112,6 +112,10 @@ struct reg_pref_t {
float pref;
};
/**
* Get the allocation info for a node.
* The info is allocated on the first visit of a node.
*/
static allocation_info_t *get_allocation_info(ir_node *node)
{
allocation_info_t *info;
......@@ -128,6 +132,14 @@ static allocation_info_t *get_allocation_info(ir_node *node)
return info;
}
/**
* Link the allocation info of a node to a copy.
* Afterwards, both nodes uses the same allocation info.
* Copy must not have an allocation info assigned yet.
*
* @param copy the node the gets the allocation info assigned
* @param value the original node
*/
static void link_to(ir_node *copy, ir_node *value)
{
allocation_info_t *info = get_allocation_info(value);
......@@ -136,6 +148,14 @@ static void link_to(ir_node *copy, ir_node *value)
mark_irn_visited(copy);
}
/**
* Calculate the penalties for every register on a node and its live neighbors.
*
* @param live_nodes the set of live nodes at the current position, may be NULL
* @param penalty the penalty to subtract from
* @param limited a raw bitset containing the limited set for the node
* @param node the node
*/
static void give_penalties_for_limits(const ir_nodeset_t *live_nodes,
float penalty, const unsigned* limited,
ir_node *node)
......@@ -177,6 +197,15 @@ static void give_penalties_for_limits(const ir_nodeset_t *live_nodes,
}
}
/**
* Calculate the preferences of a definition for the current register class.
* If the definition uses a limited set of registers, reduce the preferences
* for the limited register on the node and its neighbors.
*
* @param live_nodes the set of live nodes at the current node
* @param weight the weight
* @param node the current node
*/
static void check_defs(const ir_nodeset_t *live_nodes, float weight,
ir_node *node)
{
......@@ -227,6 +256,10 @@ static void check_defs(const ir_nodeset_t *live_nodes, float weight,
}
}
/**
* Walker: Runs an a block calculates the preferences for any
* node and every register from the considered register class.
*/
static void analyze_block(ir_node *block, void *data)
{
float weight = get_block_execfreq(execfreqs, block);
......@@ -293,6 +326,12 @@ static void analyze_block(ir_node *block, void *data)
ir_nodeset_destroy(&live_nodes);
}
/**
* Assign register reg to the given node.
*
* @param node the node
* @param reg the register
*/
static void use_reg(ir_node *node, const arch_register_t *reg)
{
unsigned r = arch_register_get_index(reg);
......@@ -308,6 +347,9 @@ static void use_reg(ir_node *node, const arch_register_t *reg)
arch_set_irn_register(node, reg);
}
/**
* Compare two register preferences in decreasing order.
*/
static int compare_reg_pref(const void *e1, const void *e2)
{
const reg_pref_t *rp1 = (const reg_pref_t*) e1;
......@@ -429,6 +471,9 @@ static void free_reg_of_value(ir_node *node)
info->current_assignment = NULL;
}
/**
* Return the index of the currently assigned register of a node.
*/
static unsigned get_current_reg(ir_node *node)
{
allocation_info_t *info = get_allocation_info(node);
......@@ -436,12 +481,23 @@ static unsigned get_current_reg(ir_node *node)
return assignment - assignments;
}
/**
* Return the currently assigned assignment of a node.
*/
static assignment_t *get_current_assignment(ir_node *node)
{
allocation_info_t *info = get_allocation_info(node);
return info->current_assignment;
}
/**
* Add an permutation in front of a node and change the assignments
* due to this permutation.
*
* @param live_nodes the set of live nodes, updated due to live range split
* @param before the node before we add the permutation
* @param permutation the permutation array (map indexes to indexes)
*/
static void permutate_values(ir_nodeset_t *live_nodes, ir_node *before,
unsigned *permutation)
{
......@@ -502,7 +558,12 @@ static void permutate_values(ir_nodeset_t *live_nodes, ir_node *before,
}
}
/* free regs for values last used */
/**
* Free regs for values last used.
*
* @param live_nodes set of live nodes, will be updated
* @param node the node to consider
*/
static void free_last_uses(ir_nodeset_t *live_nodes, ir_node *node)
{
allocation_info_t *info = get_allocation_info(node);
......@@ -511,6 +572,7 @@ static void free_last_uses(ir_nodeset_t *live_nodes, ir_node *node)
for (i = 0; i < arity; ++i) {
ir_node *op;
/* check if one operand is the last use */
if (!rbitset_is_set(&info->last_uses, i))
continue;
......@@ -520,6 +582,12 @@ static void free_last_uses(ir_nodeset_t *live_nodes, ir_node *node)
}
}
/**
* Enforce constraints at a node by live range splits.
*
* @param live_nodes the set of live nodes, might be changed
* @param node the current node
*/
static void enforce_constraints(ir_nodeset_t *live_nodes, ir_node *node)
{
int arity = get_irn_arity(node);
......@@ -539,6 +607,7 @@ static void enforce_constraints(ir_nodeset_t *live_nodes, ir_node *node)
if (!arch_irn_consider_in_reg_alloc(cls, op))
continue;
/* are there any limitations for the i'th operand? */
req = arch_get_register_req(node, i);
if ((req->type & arch_register_req_type_limited) == 0)
continue;
......@@ -546,6 +615,7 @@ static void enforce_constraints(ir_nodeset_t *live_nodes, ir_node *node)
limited = req->limited;
r = get_current_reg(op);
if (!rbitset_is_set(limited, r)) {
/* found an assignement outside the limited set */
good = false;
break;
}
......@@ -612,6 +682,10 @@ static void enforce_constraints(ir_nodeset_t *live_nodes, ir_node *node)
permutate_values(live_nodes, node, assignment);
}
/**
* Walker: assign registers to all nodes of a block that
* needs registers from the currently considered register class.
*/
static void allocate_coalesce_block(ir_node *block, void *data)
{
int i;
......@@ -712,7 +786,10 @@ static void allocate_coalesce_block(ir_node *block, void *data)
ir_nodeset_destroy(&live_nodes);
}
void be_straight_alloc_cls(void)
/**
* Run the register allocator for the current register class.
*/
static void be_straight_alloc_cls(void)
{
n_regs = arch_register_class_n_regs(cls);
lv = be_assure_liveness(birg);
......@@ -730,6 +807,9 @@ void be_straight_alloc_cls(void)
ir_free_resources(irg, IR_RESOURCE_IRN_LINK | IR_RESOURCE_IRN_VISITED);
}
/**
* Run the spiller on the current graph.
*/
static void spill(void)
{
/* TODO: rewrite pre_spill_prepare to work without chordal_env... */
......@@ -750,6 +830,9 @@ static void spill(void)
check_for_memory_operands(irg);
}
/**
* The straight register allocator for a whole procedure.
*/
static void be_straight_alloc(be_irg_t *new_birg)
{
const arch_env_t *arch_env = new_birg->main_env->arch_env;
......@@ -808,6 +891,9 @@ static be_ra_t be_ra_straight = {
be_straight_alloc,
};
/**
* Initializes this module.
*/
void be_init_straight_alloc(void)
{
FIRM_DBG_REGISTER(dbg, "firm.be.straightalloc");
......
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