Commit 402fb094 authored by Andreas Zwinkau's avatar Andreas Zwinkau
Browse files

New API function: remove_bads

The functionality already existed,
but this is necessary at more than on place.
parent 8848f5a5
......@@ -58,6 +58,15 @@ FIRM_API void local_optimize_graph(ir_graph *irg);
*/
FIRM_API int optimize_graph_df(ir_graph *irg);
/**
* Removes all Bad nodes from a graph.
*
* @param irg The graph to be optimized.
*
* @return non-zero if at least one Bad was removed, otherwise 0
*/
FIRM_API int remove_bads(ir_graph *irg);
/**
* Creates an ir_graph pass for optimize_graph_df().
*
......
......@@ -182,107 +182,6 @@ static void opt_walker(ir_node *n, void *env)
}
}
/**
* Return the number of non-Bad predecessors of the given 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;
}
/**
* Block-walker, remove Bad block predecessors and shorten Phis.
* Phi links must be uptodate.
*/
static void block_remove_bads(ir_node *block, void *env)
{
int *changed = (int *)env;
int i, j;
ir_node **new_in, *new_block, *phi;
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 */
for (i = j = 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. */
if (new_max == 0) {
ir_node *end_block = get_irg_end_block(get_irn_irg(block));
if (block == end_block) {
set_irn_in(block, new_max, new_in);
return;
}
}
new_block = new_r_Block(get_irn_irg(block), new_max, new_in);
/* 2. Remove inputs on Phis, where the block input is Bad. */
phi = get_Block_phis(block);
if (phi != NULL) {
do {
ir_node *next = get_Phi_next(phi);
if (get_irn_arity(phi) != new_max) {
ir_node *new_phi;
for (i = j = 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);
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, firm_clear_block_phis, firm_collect_block_phis, NULL);
/* actually remove Bads */
irg_block_walk_graph(irg, NULL, block_remove_bads, (void *)&changed);
return changed;
}
/* Applies local optimizations to all nodes in the graph until fixpoint. */
int optimize_graph_df(ir_graph *irg)
{
......@@ -340,7 +239,7 @@ int optimize_graph_df(ir_graph *irg)
if (! state)
edges_deactivate(irg);
if (remove_Bads(irg)) {
if (remove_bads(irg)) {
edges_deactivate(irg);
}
......
/*
* Copyright (C) 1995-2008 University of Karlsruhe. All right reserved.
*
* This file is part of libFirm.
*
* This file may be distributed and/or modified under the terms of the
* GNU General Public License version 2 as published by the Free Software
* Foundation and appearing in the file LICENSE.GPL included in the
* packaging of this file.
*
* Licensees holding valid libFirm Professional Edition licenses may use
* this file in accordance with the libFirm Commercial License.
* Agreement provided with the Software.
*
* This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
* WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE.
*/
/**
* @brief Remove all Bad nodes from ir graph
* @author Andreas Zwinkau
*/
#include "config.h"
#include <assert.h>
#include "irnode_t.h"
#include "irgopt.h"
#include "irgmod.h"
#include "irgwalk.h"
#include "irtools.h"
/**
* Return the number of non-Bad predecessors of the given 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;
}
/**
* Block-walker, remove Bad block predecessors and shorten Phis.
* Phi links must be uptodate.
*/
static void block_remove_bads(ir_node *block, void *env)
{
int *changed = (int *)env;
int i, j;
ir_node **new_in, *new_block, *phi;
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 */
for (i = j = 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. */
if (new_max == 0) {
ir_node *end_block = get_irg_end_block(get_irn_irg(block));
if (block == end_block) {
set_irn_in(block, new_max, new_in);
return;
}
}
new_block = new_r_Block(get_irn_irg(block), new_max, new_in);
/* 2. Remove inputs on Phis, where the block input is Bad. */
phi = get_Block_phis(block);
if (phi != NULL) {
do {
ir_node *next = get_Phi_next(phi);
if (get_irn_arity(phi) != new_max) {
ir_node *new_phi;
for (i = j = 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);
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.
*
* Postcondition: No Bad nodes.
*/
int remove_bads(ir_graph *irg)
{
int changed = 0;
/* build phi list per block */
irg_walk_graph(irg, firm_clear_block_phis, firm_collect_block_phis, NULL);
/* actually remove Bads */
irg_block_walk_graph(irg, NULL, block_remove_bads, (void *)&changed);
if (changed) {
edges_deactivate(irg);
}
return changed;
}
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