Commit f749db8c authored by Andreas Zwinkau's avatar Andreas Zwinkau
Browse files

optimize_graph_df removes all Bads now

parent 698b5301
......@@ -171,6 +171,107 @@ static void opt_walker(ir_node *n, void *env)
}
}
static void clear_block_phis(ir_node *node, void *env) {
(void) env;
if (is_Block(node)) {
set_Block_phis(node, NULL);
}
}
static void collect_block_phis(ir_node *node, void *env) {
(void) env;
if (is_Phi(node)) {
add_Block_phi(get_nodes_block(node), node);
}
}
static int count_non_bads(ir_node *node) {
int arity = get_irn_arity(node);
int count = 0;
int i;
for (i=0; i<arity; ++i) {
if (!is_Bad(get_irn_n(node, i)))
count++;
}
return count;
}
static void block_remove_bads(ir_node *block, int *changed) {
int i, j;
ir_node **new_in;
const int max = get_irn_arity(block);
const int new_max = count_non_bads(block);
assert (max >= new_max);
if (is_Bad(block) || max == new_max) return;
new_in = ALLOCAN(ir_node*, new_max);
*changed = 1;
assert (get_Block_dom_depth(block) >= 0);
/* 1. Create a new block without Bad inputs */
j = 0;
for (i = 0; i < max; ++i) {
ir_node *block_pred = get_irn_n(block, i);
if (!is_Bad(block_pred)) {
new_in[j++] = block_pred;
}
}
assert (j == new_max);
/* If the end block is unreachable, it might have zero predecessors. */
ir_node *end_block = get_irg_end_block(get_irn_irg(block));
if (new_max == 0 && block == end_block) {
set_irn_in(block, new_max, new_in);
return;
}
ir_node *new_block = new_r_Block(get_irn_irg(block), new_max, new_in);
/* 2. Remove inputs on Phis, where the block input is Bad. */
ir_node *phi = get_Block_phis(block);
if (phi != NULL) {
do {
ir_node* next = get_Phi_next(phi);
if (get_irn_arity(phi) != new_max) {
j = 0;
for (i = 0; i < max; ++i) {
ir_node *block_pred = get_irn_n(block, i);
if (!is_Bad(block_pred)) {
ir_node *pred = get_irn_n(phi, i);
new_in[j++] = pred;
}
}
assert (j == new_max);
ir_node *new_phi = new_r_Phi(new_block, new_max, new_in, get_irn_mode(phi));
exchange(phi, new_phi);
}
phi = next;
} while (phi != NULL);
}
exchange(block, new_block);
}
/* Remove Bad nodes from Phi and Block inputs.
*
* Precondition: No unreachable code.
* Postcondition: No Bad nodes.
*/
static int remove_Bads(ir_graph *irg) {
int changed = 0;
/* build phi list per block */
irg_walk_graph(irg, clear_block_phis, collect_block_phis, NULL);
/* actually remove Bads */
irg_block_walk_graph(irg, NULL, (void (*)(struct ir_node *, void *)) block_remove_bads, &changed);
return changed;
}
/* Applies local optimizations to all nodes in the graph until fixpoint. */
int optimize_graph_df(ir_graph *irg)
{
......@@ -232,6 +333,9 @@ int optimize_graph_df(ir_graph *irg)
end = get_irg_end(irg);
remove_End_Bads_and_doublets(end);
if (remove_Bads(irg))
edges_deactivate(irg);
clear_irg_state(irg, IR_GRAPH_STATE_BAD_BLOCK);
current_ir_graph = rem;
......
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