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* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
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*
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
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package com.sun.hotspot.igv.servercompiler;
import com.sun.hotspot.igv.data.InputBlock;
import com.sun.hotspot.igv.data.InputEdge;
import com.sun.hotspot.igv.data.InputGraph;
import com.sun.hotspot.igv.data.InputNode;
import com.sun.hotspot.igv.data.services.Scheduler;
import java.util.*;
/**
*
* @author Thomas Wuerthinger
*/
public class ServerCompilerScheduler implements Scheduler {
private static class Node {
public InputNode inputNode;
public Set<Node> succs = new HashSet<>();
public List<Node> preds = new ArrayList<>();
public InputBlock block;
public boolean isBlockProjection;
public boolean isBlockStart;
}
private InputGraph graph;
private Collection<Node> nodes;
private Map<InputNode, Node> inputNodeToNode;
private Vector<InputBlock> blocks;
private Map<InputBlock, InputBlock> dominatorMap;
private Map<InputBlock, Integer> blockIndex;
private InputBlock[][] commonDominator;
private static final Comparator<InputEdge> edgeComparator = new Comparator<InputEdge>() {
@Override
public int compare(InputEdge o1, InputEdge o2) {
return o1.getToIndex() - o2.getToIndex();
}
};
public void buildBlocks() {
blocks = new Vector<>();
Node root = findRoot();
if (root == null) {
return;
}
Stack<Node> stack = new Stack<>();
Set<Node> visited = new HashSet<>();
stack.add(root);
int blockCount = 0;
InputBlock rootBlock = null;
while (!stack.isEmpty()) {
Node proj = stack.pop();
Node parent = proj;
if (proj.isBlockProjection && proj.preds.size() > 0) {
parent = proj.preds.get(0);
}
if (!visited.contains(parent)) {
visited.add(parent);
InputBlock block = graph.addBlock(Integer.toString(blockCount));
blocks.add(block);
if (parent == root) {
rootBlock = block;
}
blockCount++;
parent.block = block;
if (proj != parent && proj.succs.size() == 1 && proj.succs.contains(root)) {
// Special treatment of Halt-nodes
proj.block = block;
}
Node p = proj;
do {
if (p.preds.size() == 0 || p.preds.get(0) == null) {
p = parent;
break;
}
p = p.preds.get(0);
if (p == proj) {
// Cycle, stop
break;
}
if (p.block == null) {
p.block = block;
}
} while (!p.isBlockProjection && !p.isBlockStart);
if (block != rootBlock) {
for (Node n : p.preds) {
if (n != null && n != p) {
if (n.isBlockProjection) {
n = n.preds.get(0);
}
if (n.block != null) {
graph.addBlockEdge(n.block, block);
}
}
}
}
for (Node n : parent.succs) {
if (n != root && n.isBlockProjection) {
for (Node n2 : n.succs) {
if (n2 != parent && n2.block != null && n2.block != rootBlock) {
graph.addBlockEdge(block, n2.block);
}
}
} else {
if (n != parent && n.block != null && n.block != rootBlock) {
graph.addBlockEdge(block, n.block);
}
}
}
int num_preds = p.preds.size();
int bottom = -1;
if (isRegion(p) || isPhi(p)) {
bottom = 0;
}
int pushed = 0;
for (int i = num_preds - 1; i > bottom; i--) {
if (p.preds.get(i) != null && p.preds.get(i) != p) {
stack.push(p.preds.get(i));
pushed++;
}
}
if (pushed == 0 && p == root) {
// TODO: special handling when root backedges are not built yet
}
}
}
for (Node n : nodes) {
InputBlock block = n.block;
if (block != null) {
block.addNode(n.inputNode.getId());
}
}
int z = 0;
blockIndex = new HashMap<>(blocks.size());
for (InputBlock b : blocks) {
blockIndex.put(b, z);
z++;
}
}
private String getBlockName(InputNode n) {
return n.getProperties().get("block");
}
@Override
public Collection<InputBlock> schedule(InputGraph graph) {
if (graph.getNodes().isEmpty()) {
return Collections.emptyList();
}
if (graph.getBlocks().size() > 0) {
Collection<InputNode> tmpNodes = new ArrayList<>(graph.getNodes());
for (InputNode n : tmpNodes) {
String block = getBlockName(n);
if (graph.getBlock(n) == null) {
graph.getBlock(block).addNode(n.getId());
assert graph.getBlock(n) != null;
}
}
return graph.getBlocks();
} else {
nodes = new ArrayList<>();
inputNodeToNode = new HashMap<>(graph.getNodes().size());
this.graph = graph;
buildUpGraph();
buildBlocks();
buildDominators();
buildCommonDominators();
scheduleLatest();
InputBlock noBlock = null;
for (InputNode n : graph.getNodes()) {
if (graph.getBlock(n) == null) {
if (noBlock == null) {
noBlock = graph.addBlock("(no block)");
blocks.add(noBlock);
}
graph.setBlock(n, noBlock);
}
assert graph.getBlock(n) != null;
}
return blocks;
}
}
private void scheduleLatest() {
Node root = findRoot();
if(root == null) {
assert false : "No root found!";
return;
}
// Mark all nodes reachable in backward traversal from root
Set<Node> reachable = new HashSet<>();
reachable.add(root);
Stack<Node> stack = new Stack<>();
stack.push(root);
while (!stack.isEmpty()) {
Node cur = stack.pop();
for (Node n : cur.preds) {
if (!reachable.contains(n)) {
reachable.add(n);
stack.push(n);
}
}
}
Set<Node> unscheduled = new HashSet<>();
for (Node n : this.nodes) {
if (n.block == null && reachable.contains(n)) {
unscheduled.add(n);
}
}
while (unscheduled.size() > 0) {
boolean progress = false;
Set<Node> newUnscheduled = new HashSet<>();
for (Node n : unscheduled) {
InputBlock block = null;
if (this.isPhi(n) && n.preds.get(0) != null) {
// Phi nodes in same block as region nodes
block = n.preds.get(0).block;
} else {
for (Node s : n.succs) {
if (reachable.contains(s)) {
if (s.block == null) {
block = null;
break;
} else {
if (block == null) {
block = s.block;
} else {
block = commonDominator[this.blockIndex.get(block)][blockIndex.get(s.block)];
}
}
}
}
}
if (block != null) {
n.block = block;
block.addNode(n.inputNode.getId());
progress = true;
} else {
newUnscheduled.add(n);
}
}
unscheduled = newUnscheduled;
if (!progress) {
break;
}
}
Set<Node> curReachable = new HashSet<>(reachable);
for (Node n : curReachable) {
if (n.block != null) {
for (Node s : n.succs) {
if (!reachable.contains(s)) {
markWithBlock(s, n.block, reachable);
}
}
}
}
}
private void markWithBlock(Node n, InputBlock b, Set<Node> reachable) {
assert !reachable.contains(n);
Stack<Node> stack = new Stack<>();
stack.push(n);
n.block = b;
b.addNode(n.inputNode.getId());
reachable.add(n);
while (!stack.isEmpty()) {
Node cur = stack.pop();
for (Node s : cur.succs) {
if (!reachable.contains(s)) {
reachable.add(s);
s.block = b;
b.addNode(s.inputNode.getId());
stack.push(s);
}
}
for (Node s : cur.preds) {
if (!reachable.contains(s)) {
reachable.add(s);
s.block = b;
b.addNode(s.inputNode.getId());
stack.push(s);
}
}
}
}
private class BlockIntermediate {
InputBlock block;
int index;
int dominator;
int semi;
int parent;
int label;
int ancestor;
List<Integer> pred;
List<Integer> bucket;
}
public void buildCommonDominators() {
commonDominator = new InputBlock[this.blocks.size()][this.blocks.size()];
for (int i = 0; i < blocks.size(); i++) {
for (int j = 0; j < blocks.size(); j++) {
commonDominator[i][j] = getCommonDominator(i, j);
}
}
}
public InputBlock getCommonDominator(int a, int b) {
InputBlock ba = blocks.get(a);
InputBlock bb = blocks.get(b);
if (ba == bb) {
return ba;
}
Set<InputBlock> visited = new HashSet<>();
while (ba != null) {
visited.add(ba);
ba = dominatorMap.get(ba);
}
while (bb != null) {
if (visited.contains(bb)) {
return bb;
}
bb = dominatorMap.get(bb);
}
assert false;
return null;
}
public void buildDominators() {
dominatorMap = new HashMap<>(graph.getBlocks().size());
if (blocks.size() == 0) {
return;
}
Vector<BlockIntermediate> intermediate = new Vector<>(graph.getBlocks().size());
Map<InputBlock, BlockIntermediate> map = new HashMap<>(graph.getBlocks().size());
int z = 0;
for (InputBlock b : blocks) {
BlockIntermediate bi = new BlockIntermediate();
bi.block = b;
bi.index = z;
bi.dominator = -1;
bi.semi = -1;
bi.parent = -1;
bi.label = z;
bi.ancestor = -1;
bi.pred = new ArrayList<>();
bi.bucket = new ArrayList<>();
intermediate.add(bi);
map.put(b, bi);
z++;
}
Stack<Integer> stack = new Stack<>();
stack.add(0);
Vector<BlockIntermediate> array = new Vector<>();
intermediate.get(0).dominator = 0;
int n = 0;
while (!stack.isEmpty()) {
int index = stack.pop();
BlockIntermediate ib = intermediate.get(index);
ib.semi = n;
array.add(ib);
n = n + 1;
for (InputBlock b : ib.block.getSuccessors()) {
BlockIntermediate succ = map.get(b);
if (succ.semi == -1) {
succ.parent = index;
stack.push(succ.index); // TODO: check if same node could be pushed twice
}
succ.pred.add(index);
}
}
for (int i = n - 1; i > 0; i--) {
BlockIntermediate block = array.get(i);
int block_index = block.index;
for (int predIndex : block.pred) {
int curIndex = eval(predIndex, intermediate);
BlockIntermediate curBlock = intermediate.get(curIndex);
if (curBlock.semi < block.semi) {
block.semi = curBlock.semi;
}
}
int semiIndex = block.semi;
BlockIntermediate semiBlock = array.get(semiIndex);
semiBlock.bucket.add(block_index);
link(block.parent, block_index, intermediate);
BlockIntermediate parentBlock = intermediate.get(block.parent);
for (int j = 0; j < parentBlock.bucket.size(); j++) {
for (int curIndex : parentBlock.bucket) {
int newIndex = eval(curIndex, intermediate);
BlockIntermediate curBlock = intermediate.get(curIndex);
BlockIntermediate newBlock = intermediate.get(newIndex);
int dom = block.parent;
if (newBlock.semi < curBlock.semi) {
dom = newIndex;
}
curBlock.dominator = dom;
}
}
parentBlock.bucket.clear();
}
for (int i = 1; i < n; i++) {
BlockIntermediate block = array.get(i);
int block_index = block.index;
int semi_index = block.semi;
BlockIntermediate semi_block = array.get(semi_index);
if (block.dominator != semi_block.index) {
int new_dom = intermediate.get(block.dominator).dominator;
block.dominator = new_dom;
}
}
for (BlockIntermediate ib : intermediate) {
if (ib.dominator == -1) {
ib.dominator = 0;
}
}
for (BlockIntermediate bi : intermediate) {
InputBlock b = bi.block;
int dominator = bi.dominator;
InputBlock dominatorBlock = null;
if (dominator != -1) {
dominatorBlock = intermediate.get(dominator).block;
}
if (dominatorBlock == b) {
dominatorBlock = null;
}
this.dominatorMap.put(b, dominatorBlock);
}
}
private void compress(int index, Vector<BlockIntermediate> blocks) {
BlockIntermediate block = blocks.get(index);
int ancestor = block.ancestor;
assert ancestor != -1;
BlockIntermediate ancestor_block = blocks.get(ancestor);
if (ancestor_block.ancestor != -1) {
compress(ancestor, blocks);
int label = block.label;
BlockIntermediate label_block = blocks.get(label);
int ancestor_label = ancestor_block.label;
BlockIntermediate ancestor_label_block = blocks.get(label);
if (ancestor_label_block.semi < label_block.semi) {
block.label = ancestor_label;
}
block.ancestor = ancestor_block.ancestor;
}
}
private int eval(int index, Vector<BlockIntermediate> blocks) {
BlockIntermediate block = blocks.get(index);
if (block.ancestor == -1) {
return index;
} else {
compress(index, blocks);
return block.label;
}
}
private void link(int index1, int index2, Vector<BlockIntermediate> blocks) {
BlockIntermediate block2 = blocks.get(index2);
block2.ancestor = index1;
}
private boolean isRegion(Node n) {
return n.inputNode.getProperties().get("name").equals("Region");
}
private boolean isPhi(Node n) {
return n.inputNode.getProperties().get("name").equals("Phi");
}
private Node findRoot() {
Node minNode = null;
Node alternativeRoot = null;
for (Node node : nodes) {
InputNode inputNode = node.inputNode;
String s = inputNode.getProperties().get("name");
if (s != null && s.equals("Root")) {
return node;
}
if (alternativeRoot == null && node.preds.isEmpty()) {
alternativeRoot = node;
}
if (minNode == null || node.inputNode.getId() < minNode.inputNode.getId()) {
minNode = node;
}
}
if (alternativeRoot != null) {
return alternativeRoot;
} else {
return minNode;
}
}
public void buildUpGraph() {
for (InputNode n : graph.getNodes()) {
Node node = new Node();
node.inputNode = n;
nodes.add(node);
String p = n.getProperties().get("is_block_proj");
node.isBlockProjection = (p != null && p.equals("true"));
p = n.getProperties().get("is_block_start");
node.isBlockStart = (p != null && p.equals("true"));
inputNodeToNode.put(n, node);
}
Map<Integer, List<InputEdge>> edgeMap = new HashMap<>(graph.getEdges().size());
for (InputEdge e : graph.getEdges()) {
int to = e.getTo();
if (!edgeMap.containsKey(to)) {
edgeMap.put(to, new ArrayList<InputEdge>());
}
List<InputEdge> list = edgeMap.get(to);
list.add(e);
}
for (Integer i : edgeMap.keySet()) {
List<InputEdge> list = edgeMap.get(i);
Collections.sort(list, edgeComparator);
int to = i;
InputNode toInputNode = graph.getNode(to);
Node toNode = inputNodeToNode.get(toInputNode);
for (InputEdge e : list) {
assert to == e.getTo();
int from = e.getFrom();
InputNode fromInputNode = graph.getNode(from);
Node fromNode = inputNodeToNode.get(fromInputNode);
fromNode.succs.add(toNode);
toNode.preds.add(fromNode);
}
}
}
}