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);
}
}
}
/**
* Actually run the optimization rules over the graph.
*
* This will re-run the optimizers if anything was changed in a run. This
* allows for optimizations to happen in any order, and for one optimization
* to open the door to another.
*
* Unfortunately, this also makes this process EXTREMELY expensive.
*
* This is O(scary).
*/
public function process(GraphState $state)
{
$graph = $state->getGraph();
do {
$rerun = false;
foreach ($graph->vertices() as $vertex) {
foreach ($this->rules as $rule) {
$rerun = $rerun || $rule->process($vertex, $graph);
}
}
} while ($rerun);
}
public function removePhi(Phi $vertex, GraphState $state)
{
$graph = $state->getGraph();
Helper::remove($vertex, $graph);
$to = $vertex->getResult();
foreach ($vertex->getValues() as $value) {
foreach ($graph->vertices() as $v) {
$v->replaceVariable($value, $to);
if ($v instanceof Assignment && $v->getResult() === $value) {
$v->setResult($to);
}
}
}
}
/**
* @covers ::__construct
* @covers ::getGraph
* @covers ::getFunction
* @covers ::getDominator
* @covers ::getPostDominator
* @covers ::getInverseGraph
*/
public function testBasicUsage()
{
$func = new JitFunction([], new Type(0), $graph = new DirectedAdjacencyList());
$graph->ensureArc($func, new End());
$state = new GraphState($func);
$this->assertSame($func, $state->getFunction());
$this->assertSame($graph, $state->getGraph());
$this->assertInstanceOf(Dominator::class, $state->getDominator());
$this->assertInstanceOf(Dominator::class, $state->getPostDominator());
$this->assertInstanceOf(DirectedAdjacencyList::class, $state->getInverseGraph());
}
public function process(GraphState $state)
{
$graph = $state->getGraph();
$assignments = array_merge(Helper::findVerticesByClass(JitAssignment::class, $graph), [$state->getFunction()]);
$vars = Helper::findVariables($graph);
$dominator = $state->getDominator();
foreach ($vars as $var) {
$hash = spl_object_hash($var);
$varAssignments = $this->findAssignmentsByVar($var, $assignments);
$phi = $this->findPhiNodes($var, $varAssignments, $dominator, $graph);
$this->implementSSA($var, $var, $state->getFunction(), $graph, $phi, $state->getFunction()->getArguments());
$this->stack->removeAll($this->stack);
}
}