--- old/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.loop.phases/src/org/graalvm/compiler/loop/phases/ReassociateInvariantPhase.java 2017-08-03 22:42:49.386367706 -0700 +++ new/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.loop.phases/src/org/graalvm/compiler/loop/phases/ReassociateInvariantPhase.java 2017-08-03 22:42:49.289363357 -0700 @@ -26,24 +26,34 @@ import org.graalvm.compiler.loop.LoopEx; import org.graalvm.compiler.loop.LoopsData; import org.graalvm.compiler.nodes.StructuredGraph; +import org.graalvm.compiler.nodes.calc.BinaryArithmeticNode; import org.graalvm.compiler.phases.Phase; +/** + * Rearrange {@link BinaryArithmeticNode#isAssociative() associative binary operations} so that + * invariant parts of the expression can move outside of the loop. + */ public class ReassociateInvariantPhase extends Phase { @SuppressWarnings("try") @Override protected void run(StructuredGraph graph) { - if (graph.hasLoops()) { - final LoopsData dataReassociate = new LoopsData(graph); - DebugContext debug = graph.getDebug(); - try (DebugContext.Scope s = debug.scope("ReassociateInvariants")) { + int iterations = 0; + DebugContext debug = graph.getDebug(); + try (DebugContext.Scope s = debug.scope("ReassociateInvariants")) { + boolean changed = true; + while (changed) { + changed = false; + final LoopsData dataReassociate = new LoopsData(graph); for (LoopEx loop : dataReassociate.loops()) { - loop.reassociateInvariants(); + changed |= loop.reassociateInvariants(); } - } catch (Throwable e) { - throw debug.handle(e); + dataReassociate.deleteUnusedNodes(); + iterations++; + debug.dump(DebugContext.VERBOSE_LEVEL, graph, "after iteration %d", iterations); } - dataReassociate.deleteUnusedNodes(); + } catch (Throwable e) { + throw debug.handle(e); } } }