示例#1
0
 public static void checkRedundantProxy(ProxyNode vpn) {
   if (vpn.isDeleted()) {
     return;
   }
   BeginNode proxyPoint = vpn.proxyPoint();
   if (proxyPoint instanceof LoopExitNode) {
     LoopExitNode exit = (LoopExitNode) proxyPoint;
     LoopBeginNode loopBegin = exit.loopBegin();
     Node vpnValue = vpn.value();
     for (ValueNode v : loopBegin.stateAfter().values()) {
       ValueNode v2 = v;
       if (loopBegin.isPhiAtMerge(v2)) {
         v2 = ((PhiNode) v2).valueAt(loopBegin.forwardEnd());
       }
       if (vpnValue == v2) {
         Collection<PhiNode> phiUsages = vpn.usages().filter(PhiNode.class).snapshot();
         Collection<ProxyNode> proxyUsages = vpn.usages().filter(ProxyNode.class).snapshot();
         vpn.graph().replaceFloating(vpn, vpnValue);
         for (PhiNode phi : phiUsages) {
           checkRedundantPhi(phi);
         }
         for (ProxyNode proxy : proxyUsages) {
           checkRedundantProxy(proxy);
         }
         return;
       }
     }
   }
 }
示例#2
0
 public static void normalizeLoopBegin(LoopBeginNode begin) {
   // Delete unnecessary loop phi functions, i.e., phi functions where all inputs are either
   // the same or the phi itself.
   for (PhiNode phi : begin.phis().snapshot()) {
     GraphUtil.checkRedundantPhi(phi);
   }
   for (LoopExitNode exit : begin.loopExits()) {
     for (ProxyNode vpn : exit.proxies().snapshot()) {
       GraphUtil.checkRedundantProxy(vpn);
     }
   }
 }
示例#3
0
 private static void killEnd(AbstractEndNode end, SimplifierTool tool) {
   MergeNode merge = end.merge();
   if (merge != null) {
     merge.removeEnd(end);
     StructuredGraph graph = end.graph();
     if (merge instanceof LoopBeginNode && merge.forwardEndCount() == 0) {
       // dead loop
       for (PhiNode phi : merge.phis().snapshot()) {
         propagateKill(phi);
       }
       LoopBeginNode begin = (LoopBeginNode) merge;
       // disconnect and delete loop ends & loop exits
       for (LoopEndNode loopend : begin.loopEnds().snapshot()) {
         loopend.predecessor().replaceFirstSuccessor(loopend, null);
         loopend.safeDelete();
       }
       begin.removeExits();
       FixedNode loopBody = begin.next();
       if (loopBody != null) { // for small infinite loops, the body may be killed while
         // killing the loop ends
         killCFG(loopBody);
       }
       begin.safeDelete();
     } else if (merge instanceof LoopBeginNode && ((LoopBeginNode) merge).loopEnds().isEmpty()) {
       // not a loop anymore
       if (tool != null) {
         merge.phis().forEach(phi -> tool.addToWorkList(phi.usages()));
       }
       graph.reduceDegenerateLoopBegin((LoopBeginNode) merge);
     } else if (merge.phiPredecessorCount() == 1) {
       // not a merge anymore
       if (tool != null) {
         merge.phis().forEach(phi -> tool.addToWorkList(phi.usages()));
       }
       graph.reduceTrivialMerge(merge);
     }
   }
 }