public function process(GraphState $state)
{
$graph = $state->getGraph();
$vars = Helper::findVariables($graph);
$postdominator = $state->getPostDominator();
$dominator = $state->getDominator();
foreach ($vars as $var) {
$usages = [];
foreach ($graph->vertices() as $vertex) {
if (in_array($var, $vertex->getVariables(), true)) {
$usages[] = $vertex;
}
}
$dom = $postdominator->immediateDominatorArray($usages);
while ($dom) {
foreach ($usages as $usage) {
if ($dominator->strictlyDominates($usage, $dom)) {
$dom = $postdominator->immediateDominator($dom);
continue 2;
}
}
break;
}
if (!$dom) {
continue;
}
if ($dom instanceof Jump || $dom instanceof JumpZ) {
Helper::insertBefore($dom, new Free($var), $graph);
} else {
Helper::insertAfter($dom, new Free($var), $graph);
}
}
}
public function implementSSA(Variable $old, Variable $new, Vertex $vertex, Digraph $graph, \SplObjectStorage $phiNodes, array $args)
{
if ($this->stack->contains($vertex)) {
if (isset($phiNodes[$vertex])) {
// we've visited, so it **must** have a node implemented
$phiNodes[$vertex]->addValue($new);
}
return;
}
$this->stack->attach($vertex);
if ($old !== $new && !$vertex instanceof Phi) {
$vertex->replaceVariable($old, $new);
}
if ($vertex instanceof JitAssignment && $vertex->getResult() === $old) {
$new = new Variable($new->getType());
$vertex->setResult($new);
}
if (isset($phiNodes[$vertex])) {
if ($phiNodes[$vertex] === true) {
// insert phiNode
$next = new Variable();
$phi = new Phi($next);
$phiNodes[$vertex] = $phi;
if ($old !== $new || in_array($old, $args, true)) {
$phiNodes[$vertex]->addValue($new);
}
Helper::insertAfter($vertex, $phiNodes[$vertex], $graph);
$new = $next;
} else {
$phiNodes[$vertex]->addValue($new);
}
}
foreach ($graph->successorsOf($vertex) as $sub) {
// Depth first search
$this->implementSSA($old, $new, $sub, $graph, $phiNodes, $args);
}
}
/**
* @covers ::insertAfter
*/
public function testInsertAfterDouble()
{
Helper::insertAfter($this->v[1], $this->v[6], $this->graph);
$adj = $this->getValues($this->graph->successorsOf($this->v[1]));
$this->assertEquals(1, count($adj));
$this->assertSame($this->v[6], $adj[0]);
$adj = $this->getValues($this->graph->successorsOf($this->v[6]));
$this->assertEquals(2, count($adj));
$this->assertSame($this->v[2], $adj[0]);
$this->assertSame($this->v[3], $adj[1]);
}
