Revert "Fix scheduler to correctly schedule nested diamonds."

This reverts commit 0ab306041a6eba99fe5e2ef78251de137321f559.

"Fix" make scheduler run out of memory.

TBR=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/656473002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24566 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/compiler/scheduler.cc

@@ -34,7 +34,7 @@ Scheduler::Scheduler(Zone* zone, Graph* graph, Schedule* schedule)
       schedule_(schedule),
       scheduled_nodes_(zone),
       schedule_root_nodes_(zone),
-      node_data_(graph_->NodeCount(), DefaultSchedulerData(zone), zone),
+      node_data_(graph_->NodeCount(), DefaultSchedulerData(), zone),
       has_floating_control_(false) {}
 
 
@@ -62,8 +62,8 @@ Schedule* Scheduler::ComputeSchedule(Graph* graph) {
 }
 
 
-Scheduler::SchedulerData Scheduler::DefaultSchedulerData(Zone* zone) {
-  SchedulerData def = {0, -1, false, false, kUnknown, NodeVector(zone)};
+Scheduler::SchedulerData Scheduler::DefaultSchedulerData() {
+  SchedulerData def = {0, -1, false, false, kUnknown};
   return def;
 }
 
@@ -182,7 +182,6 @@ class CFGBuilder {
     }
   }
 
-
   void BuildBlocks(Node* node) {
     switch (node->opcode()) {
       case IrOpcode::kLoop:
@@ -396,26 +395,6 @@ class PrepareUsesVisitor : public NullNodeVisitor {
       Trace("  Use count of #%d:%s (used by #%d:%s)++ = %d\n", to->id(),
             to->op()->mnemonic(), from->id(), from->op()->mnemonic(),
             scheduler_->GetData(to)->unscheduled_count_);
-      if (OperatorProperties::IsBasicBlockBegin(to->op()) &&
-          (from->opcode() == IrOpcode::kEffectPhi ||
-           from->opcode() == IrOpcode::kPhi) &&
-          scheduler_->GetData(to)->is_floating_control_ &&
-          !scheduler_->GetData(to)->is_connected_control_) {
-        for (InputIter i = from->inputs().begin(); i != from->inputs().end();
-             ++i) {
-          if (!NodeProperties::IsControlEdge(i.edge())) {
-            Scheduler::SchedulerData* data = scheduler_->GetData(to);
-            data->additional_dependencies.push_back(*i);
-            ++(scheduler_->GetData(*i)->unscheduled_count_);
-            Trace(
-                "  Use count of #%d:%s (additional dependency of #%d:%s)++ = "
-                "%d\n",
-                (*i)->id(), (*i)->op()->mnemonic(), to->id(),
-                to->op()->mnemonic(),
-                scheduler_->GetData(*i)->unscheduled_count_);
-          }
-        }
-      }
     }
   }
 
@@ -530,7 +509,6 @@ class ScheduleLateNodeVisitor : public NullNodeVisitor {
     if (schedule_->IsScheduled(node)) {
       return GenericGraphVisit::CONTINUE;
     }
-
     Scheduler::SchedulerData* data = scheduler_->GetData(node);
     DCHECK_EQ(Scheduler::kSchedulable, data->placement_);
 
@@ -633,24 +611,6 @@ class ScheduleLateNodeVisitor : public NullNodeVisitor {
         }
       }
     }
-
-    Scheduler::SchedulerData* data = scheduler_->GetData(node);
-    for (NodeVectorIter i = data->additional_dependencies.begin();
-         i != data->additional_dependencies.end(); ++i) {
-      Scheduler::SchedulerData* data = scheduler_->GetData(*i);
-      DCHECK(data->unscheduled_count_ > 0);
-      --data->unscheduled_count_;
-      if (FLAG_trace_turbo_scheduler) {
-        Trace(
-            "  Use count for #%d:%s (additional dependency of #%d:%s)-- = %d\n",
-            (*i)->id(), (*i)->op()->mnemonic(), node->id(),
-            node->op()->mnemonic(), data->unscheduled_count_);
-        if (data->unscheduled_count_ == 0) {
-          Trace("  newly eligible #%d:%s\n", (*i)->id(),
-                (*i)->op()->mnemonic());
-        }
-      }
-    }
   }
 
   Scheduler* scheduler_;
@@ -709,14 +669,16 @@ bool Scheduler::ConnectFloatingControl() {
     // TODO(titzer): we place at most one floating control structure per
     // basic block because scheduling currently can interleave phis from
     // one subgraph with the merges from another subgraph.
+    bool one_placed = false;
     for (size_t j = 0; j < block->NodeCount(); j++) {
       Node* node = block->NodeAt(block->NodeCount() - 1 - j);
       SchedulerData* data = GetData(node);
-      if (data->is_floating_control_ && !data->is_connected_control_) {
+      if (data->is_floating_control_ && !data->is_connected_control_ &&
+          !one_placed) {
         Trace("  Floating control #%d:%s was scheduled in B%d\n", node->id(),
               node->op()->mnemonic(), block->id().ToInt());
         ConnectFloatingControlSubgraph(block, node);
-        return true;
+        one_placed = true;
       }
     }
   }

src/compiler/scheduler.h

@@ -36,9 +36,8 @@ class Scheduler {
     bool is_connected_control_;  // {true} if control-connected to the end node.
     bool is_floating_control_;   // {true} if control, but not control-connected
                                  // to the end node.
-    Placement placement_;        // Whether the node is fixed, schedulable,
+    Placement placement_ : 3;    // Whether the node is fixed, schedulable,
                                  // or not yet known.
-    NodeVector additional_dependencies;
   };
 
   Zone* zone_;
@@ -51,7 +50,7 @@ class Scheduler {
 
   Scheduler(Zone* zone, Graph* graph, Schedule* schedule);
 
-  SchedulerData DefaultSchedulerData(Zone* zone);
+  SchedulerData DefaultSchedulerData();
 
   SchedulerData* GetData(Node* node) {
     DCHECK(node->id() < static_cast<int>(node_data_.size()));

src/compiler/verifier.cc

@@ -271,19 +271,6 @@ static bool HasDominatingDef(Schedule* schedule, Node* node,
 }
 
 
-static bool Dominates(Schedule* schedule, Node* dominator, Node* dominatee) {
-  BasicBlock* dom = schedule->block(dominator);
-  BasicBlock* sub = schedule->block(dominatee);
-  while (sub != NULL) {
-    if (sub == dom) {
-      return true;
-    }
-    sub = sub->dominator();
-  }
-  return false;
-}
-
-
 static void CheckInputsDominate(Schedule* schedule, BasicBlock* block,
                                 Node* node, int use_pos) {
   for (int j = OperatorProperties::GetValueInputCount(node->op()) - 1; j >= 0;
@@ -302,19 +289,6 @@ static void CheckInputsDominate(Schedule* schedule, BasicBlock* block,
                input->id(), input->op()->mnemonic());
     }
   }
-  // Ensure that nodes are dominated by their control inputs;
-  // kEnd is an exception, as unreachable blocks resulting from kMerge
-  // are not in the RPO.
-  if (OperatorProperties::GetControlInputCount(node->op()) == 1 &&
-      node->opcode() != IrOpcode::kEnd) {
-    Node* ctl = NodeProperties::GetControlInput(node);
-    if (!Dominates(schedule, ctl, node)) {
-      V8_Fatal(__FILE__, __LINE__,
-               "Node #%d:%s in B%d is not dominated by control input #%d:%s",
-               node->id(), node->op()->mnemonic(), block->id(), ctl->id(),
-               ctl->op()->mnemonic());
-    }
-  }
 }
 
 

test/cctest/compiler/test-scheduler.cc

@@ -5,7 +5,6 @@
 #include "src/v8.h"
 #include "test/cctest/cctest.h"
 
-#include "src/compiler/access-builder.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/generic-node-inl.h"
 #include "src/compiler/generic-node.h"
@@ -17,7 +16,6 @@
 #include "src/compiler/operator.h"
 #include "src/compiler/schedule.h"
 #include "src/compiler/scheduler.h"
-#include "src/compiler/simplified-operator.h"
 #include "src/compiler/verifier.h"
 
 using namespace v8::internal;
@@ -1719,85 +1717,4 @@ TEST(FloatingDiamond3) {
   ComputeAndVerifySchedule(33, &graph);
 }
 
-
-TEST(NestedFloatingDiamonds) {
-  HandleAndZoneScope scope;
-  Graph graph(scope.main_zone());
-  CommonOperatorBuilder common(scope.main_zone());
-  SimplifiedOperatorBuilder simplified(scope.main_zone());
-  MachineOperatorBuilder machine;
-
-  Node* start = graph.NewNode(common.Start(2));
-  graph.SetStart(start);
-
-  Node* p0 = graph.NewNode(common.Parameter(0), start);
-
-  Node* fv = graph.NewNode(common.Int32Constant(7));
-  Node* br = graph.NewNode(common.Branch(), p0, graph.start());
-  Node* t = graph.NewNode(common.IfTrue(), br);
-  Node* f = graph.NewNode(common.IfFalse(), br);
-
-  Node* map = graph.NewNode(
-      simplified.LoadElement(AccessBuilder::ForFixedArrayElement()), p0, p0, p0,
-      start, f);
-  Node* br1 = graph.NewNode(common.Branch(), map, graph.start());
-  Node* t1 = graph.NewNode(common.IfTrue(), br1);
-  Node* f1 = graph.NewNode(common.IfFalse(), br1);
-  Node* m1 = graph.NewNode(common.Merge(2), t1, f1);
-  Node* ttrue = graph.NewNode(common.Int32Constant(1));
-  Node* ffalse = graph.NewNode(common.Int32Constant(0));
-  Node* phi1 = graph.NewNode(common.Phi(kMachAnyTagged, 2), ttrue, ffalse, m1);
-
-
-  Node* m = graph.NewNode(common.Merge(2), t, f);
-  Node* phi = graph.NewNode(common.Phi(kMachAnyTagged, 2), fv, phi1, m);
-  Node* ephi1 = graph.NewNode(common.EffectPhi(2), start, map, m);
-
-  Node* ret = graph.NewNode(common.Return(), phi, ephi1, start);
-  Node* end = graph.NewNode(common.End(), ret, start);
-
-  graph.SetEnd(end);
-
-  ComputeAndVerifySchedule(23, &graph);
-}
-
-
-TEST(PhisPushedDownToDifferentBranches) {
-  HandleAndZoneScope scope;
-  Graph graph(scope.main_zone());
-  CommonOperatorBuilder common(scope.main_zone());
-  SimplifiedOperatorBuilder simplified(scope.main_zone());
-  MachineOperatorBuilder machine;
-
-  Node* start = graph.NewNode(common.Start(2));
-  graph.SetStart(start);
-
-  Node* p0 = graph.NewNode(common.Parameter(0), start);
-  Node* p1 = graph.NewNode(common.Parameter(1), start);
-
-  Node* v1 = graph.NewNode(common.Int32Constant(1));
-  Node* v2 = graph.NewNode(common.Int32Constant(2));
-  Node* v3 = graph.NewNode(common.Int32Constant(3));
-  Node* v4 = graph.NewNode(common.Int32Constant(4));
-  Node* br = graph.NewNode(common.Branch(), p0, graph.start());
-  Node* t = graph.NewNode(common.IfTrue(), br);
-  Node* f = graph.NewNode(common.IfFalse(), br);
-  Node* m = graph.NewNode(common.Merge(2), t, f);
-  Node* phi = graph.NewNode(common.Phi(kMachAnyTagged, 2), v1, v2, m);
-  Node* phi2 = graph.NewNode(common.Phi(kMachAnyTagged, 2), v3, v4, m);
-
-  Node* br2 = graph.NewNode(common.Branch(), p1, graph.start());
-  Node* t2 = graph.NewNode(common.IfTrue(), br2);
-  Node* f2 = graph.NewNode(common.IfFalse(), br2);
-  Node* m2 = graph.NewNode(common.Merge(2), t2, f2);
-  Node* phi3 = graph.NewNode(common.Phi(kMachAnyTagged, 2), phi, phi2, m2);
-
-  Node* ret = graph.NewNode(common.Return(), phi3, start, start);
-  Node* end = graph.NewNode(common.End(), ret, start);
-
-  graph.SetEnd(end);
-
-  ComputeAndVerifySchedule(24, &graph);
-}
-
 #endif