Model exceptional edges from call nodes in TurboFan.

src/compiler/scheduler.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/scheduler.h"
 
 #include "src/bit-vector.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/control-equivalence.h"
 #include "src/compiler/graph.h"
@@ skipping 268 matching lines @@
       }
     }
     DCHECK(component_entry_);
 
     for (NodeVector::iterator i = control_.begin(); i != control_.end(); ++i) {
       ConnectBlocks(*i);  // Connect block to its predecessor/successors.
     }
   }
 
  private:
-  // TODO(mstarzinger): Only for Scheduler::FuseFloatingControl.
+  friend class ScheduleLateNodeVisitor;
   friend class Scheduler;
 
   void FixNode(BasicBlock* block, Node* node) {
     schedule_->AddNode(block, node);
     scheduler_->UpdatePlacement(node, Scheduler::kFixed);
   }
 
   void Queue(Node* node) {
     // Mark the connected control nodes as they are queued.
     if (!queued_.Get(node)) {
@@ skipping 13 matching lines @@
         FixNode(schedule_->start(), node);
         break;
       case IrOpcode::kLoop:
       case IrOpcode::kMerge:
         BuildBlockForNode(node);
         break;
       case IrOpcode::kBranch:
       case IrOpcode::kSwitch:
         BuildBlocksForSuccessors(node);
         break;
+      case IrOpcode::kCall:
+        if (!IsExceptionalCall(node)) break;
+        BuildBlocksForSuccessors(node);
+        break;
       default:
         break;
     }
   }
 
   void ConnectBlocks(Node* node) {
     switch (node->opcode()) {
       case IrOpcode::kLoop:
       case IrOpcode::kMerge:
         ConnectMerge(node);
         break;
       case IrOpcode::kBranch:
         scheduler_->UpdatePlacement(node, Scheduler::kFixed);
         ConnectBranch(node);
         break;
       case IrOpcode::kSwitch:
         scheduler_->UpdatePlacement(node, Scheduler::kFixed);
         ConnectSwitch(node);
         break;
       case IrOpcode::kReturn:
         scheduler_->UpdatePlacement(node, Scheduler::kFixed);
         ConnectReturn(node);
         break;
       case IrOpcode::kThrow:
         scheduler_->UpdatePlacement(node, Scheduler::kFixed);
         ConnectThrow(node);
         break;
+      case IrOpcode::kCall:
+        if (!IsExceptionalCall(node)) break;
+        scheduler_->UpdatePlacement(node, Scheduler::kFixed);
+        ConnectCall(node);
+        break;
       default:
         break;
     }
   }
 
   BasicBlock* BuildBlockForNode(Node* node) {
     BasicBlock* block = schedule_->block(node);
     if (block == NULL) {
       block = schedule_->NewBasicBlock();
       Trace("Create block B%d for #%d:%s\n", block->id().ToInt(), node->id(),
             node->op()->mnemonic());
       FixNode(block, node);
     }
     return block;
   }
 
   void BuildBlocksForSuccessors(Node* node) {
     size_t const successor_count = node->op()->ControlOutputCount();
     Node** successors = zone_->NewArray<Node*>(successor_count);
     CollectSuccessorProjections(node, successors, successor_count);
     for (size_t index = 0; index < successor_count; ++index) {
       BuildBlockForNode(successors[index]);
     }
   }
 
   // Collect the branch-related projections from a node, such as IfTrue,
-  // IfFalse, and Case.
+  // IfFalse, IfException, IfSuccess, and Case.
   void CollectSuccessorProjections(Node* node, Node** successors,
                                    size_t successor_count) {
 #ifdef DEBUG
-    DCHECK_EQ(static_cast<int>(successor_count), node->UseCount());
+    DCHECK_LE(static_cast<int>(successor_count), node->UseCount());
     std::memset(successors, 0, sizeof(*successors) * successor_count);
 #endif
     for (Node* const use : node->uses()) {
       size_t index;
       switch (use->opcode()) {
-        default:
-          UNREACHABLE();
-        // Fall through.
         case IrOpcode::kIfTrue:
           DCHECK_EQ(IrOpcode::kBranch, node->opcode());
           index = 0;
           break;
         case IrOpcode::kIfFalse:
           DCHECK_EQ(IrOpcode::kBranch, node->opcode());
           index = 1;
           break;
+        case IrOpcode::kIfException:
+          DCHECK_EQ(IrOpcode::kCall, node->opcode());
+          index = 1;
+          break;
+        case IrOpcode::kIfSuccess:
+          DCHECK_EQ(IrOpcode::kCall, node->opcode());
+          index = 0;
+          break;
         case IrOpcode::kCase:
           DCHECK_EQ(IrOpcode::kSwitch, node->opcode());
           index = CaseIndexOf(use->op());
           break;
+        default:
+          continue;
       }
       DCHECK_LT(index, successor_count);
       DCHECK(successors[index] == nullptr);
       successors[index] = use;
     }
 #ifdef DEBUG
     for (size_t index = 0; index < successor_count; ++index) {
       DCHECK_NOT_NULL(successors[index]);
     }
 #endif
   }
 
   void CollectSuccessorBlocks(Node* node, BasicBlock** successor_blocks,
                               size_t successor_count) {
     Node** successors = reinterpret_cast<Node**>(successor_blocks);
     CollectSuccessorProjections(node, successors, successor_count);
     for (size_t index = 0; index < successor_count; ++index) {
       successor_blocks[index] = schedule_->block(successors[index]);
     }
   }
 
+  BasicBlock* FindPredecessorBlock(Node* node) {
+    BasicBlock* predecessor_block = nullptr;
+    while (predecessor_block == nullptr) {

[Benedikt Meurer, 2015/02/17 05:58:49]

The condition is redundant; can be while(true) instead.

[Michael Starzinger, 2015/02/17 10:12:06]

Done.

+      predecessor_block = schedule_->block(node);
+      if (predecessor_block != nullptr) break;
+      node = NodeProperties::GetControlInput(node);
+    }
+    return predecessor_block;
+  }
+
+  void ConnectCall(Node* call) {
+    BasicBlock* successor_blocks[2];
+    CollectSuccessorBlocks(call, successor_blocks, arraysize(successor_blocks));
+
+    // Consider the exception continuation to be deferred.
+    successor_blocks[1]->set_deferred(true);
+
+    Node* call_control = NodeProperties::GetControlInput(call);
+    BasicBlock* call_block = FindPredecessorBlock(call_control);
+    TraceConnect(call, call_block, successor_blocks[0]);
+    TraceConnect(call, call_block, successor_blocks[1]);
+    schedule_->AddCall(call_block, call, successor_blocks[0],
+                       successor_blocks[1]);
+  }
+
   void ConnectBranch(Node* branch) {
     BasicBlock* successor_blocks[2];
     CollectSuccessorBlocks(branch, successor_blocks,
                            arraysize(successor_blocks));
 
     // Consider branch hints.
     switch (BranchHintOf(branch->op())) {
       case BranchHint::kNone:
         break;
       case BranchHint::kTrue:
         successor_blocks[1]->set_deferred(true);
         break;
       case BranchHint::kFalse:
         successor_blocks[0]->set_deferred(true);
         break;
     }
 
     if (branch == component_entry_) {
       TraceConnect(branch, component_start_, successor_blocks[0]);
       TraceConnect(branch, component_start_, successor_blocks[1]);
       schedule_->InsertBranch(component_start_, component_end_, branch,
                               successor_blocks[0], successor_blocks[1]);
     } else {
-      Node* branch_block_node = NodeProperties::GetControlInput(branch);
-      BasicBlock* branch_block = schedule_->block(branch_block_node);
-      DCHECK_NOT_NULL(branch_block);
-
+      Node* branch_control = NodeProperties::GetControlInput(branch);
+      BasicBlock* branch_block = FindPredecessorBlock(branch_control);
       TraceConnect(branch, branch_block, successor_blocks[0]);
       TraceConnect(branch, branch_block, successor_blocks[1]);
       schedule_->AddBranch(branch_block, branch, successor_blocks[0],
                            successor_blocks[1]);
     }
   }
 
   void ConnectSwitch(Node* sw) {
     size_t const successor_count = sw->op()->ControlOutputCount();
     BasicBlock** successor_blocks =
         zone_->NewArray<BasicBlock*>(successor_count);
     CollectSuccessorBlocks(sw, successor_blocks, successor_count);
 
     if (sw == component_entry_) {
       for (size_t index = 0; index < successor_count; ++index) {
         TraceConnect(sw, component_start_, successor_blocks[index]);
       }
       schedule_->InsertSwitch(component_start_, component_end_, sw,
                               successor_blocks, successor_count);
     } else {
-      Node* sw_block_node = NodeProperties::GetControlInput(sw);
-      BasicBlock* sw_block = schedule_->block(sw_block_node);
-      DCHECK_NOT_NULL(sw_block);
-
+      Node* switch_control = NodeProperties::GetControlInput(sw);
+      BasicBlock* switch_block = FindPredecessorBlock(switch_control);
       for (size_t index = 0; index < successor_count; ++index) {
-        TraceConnect(sw, sw_block, successor_blocks[index]);
+        TraceConnect(sw, switch_block, successor_blocks[index]);
       }
-      schedule_->AddSwitch(sw_block, sw, successor_blocks, successor_count);
+      schedule_->AddSwitch(switch_block, sw, successor_blocks, successor_count);
     }
   }
 
   void ConnectMerge(Node* merge) {
     // Don't connect the special merge at the end to its predecessors.
     if (IsFinalMerge(merge)) return;
 
     BasicBlock* block = schedule_->block(merge);
     DCHECK_NOT_NULL(block);
     // For all of the merge's control inputs, add a goto at the end to the
     // merge's basic block.
     for (Node* const input : merge->inputs()) {
-      BasicBlock* predecessor_block = schedule_->block(input);
+      BasicBlock* predecessor_block = FindPredecessorBlock(input);
       TraceConnect(merge, predecessor_block, block);
       schedule_->AddGoto(predecessor_block, block);
     }
   }
 
   void ConnectReturn(Node* ret) {
-    Node* return_block_node = NodeProperties::GetControlInput(ret);
-    BasicBlock* return_block = schedule_->block(return_block_node);
+    Node* return_control = NodeProperties::GetControlInput(ret);
+    BasicBlock* return_block = FindPredecessorBlock(return_control);
     TraceConnect(ret, return_block, NULL);
     schedule_->AddReturn(return_block, ret);
   }
 
   void ConnectThrow(Node* thr) {
-    Node* throw_block_node = NodeProperties::GetControlInput(thr);
-    BasicBlock* throw_block = schedule_->block(throw_block_node);
+    Node* throw_control = NodeProperties::GetControlInput(thr);
+    BasicBlock* throw_block = FindPredecessorBlock(throw_control);
     TraceConnect(thr, throw_block, NULL);
     schedule_->AddThrow(throw_block, thr);
   }
 
   void TraceConnect(Node* node, BasicBlock* block, BasicBlock* succ) {
     DCHECK_NOT_NULL(block);
     if (succ == NULL) {
       Trace("Connect #%d:%s, B%d -> end\n", node->id(), node->op()->mnemonic(),
             block->id().ToInt());
     } else {
       Trace("Connect #%d:%s, B%d -> B%d\n", node->id(), node->op()->mnemonic(),
             block->id().ToInt(), succ->id().ToInt());
     }
   }
 
+  bool IsExceptionalCall(Node* node) {
+    for (Node* const use : node->uses()) {
+      if (use->opcode() == IrOpcode::kIfException) return true;
+    }
+    return false;
+  }
+
   bool IsFinalMerge(Node* node) {
     return (node->opcode() == IrOpcode::kMerge &&
             node == scheduler_->graph_->end()->InputAt(0));
   }
 
   bool IsSingleEntrySingleExitRegion(Node* entry, Node* exit) const {
     size_t entry_class = scheduler_->equivalence_->ClassOf(entry);
     size_t exit_class = scheduler_->equivalence_->ClassOf(exit);
     return entry != exit && entry_class == exit_class;
   }
@@ skipping 825 matching lines @@
         block = hoist_block;
         hoist_block = GetPreHeader(hoist_block);
       } while (hoist_block &&
                hoist_block->dominator_depth() >= min_block->dominator_depth());
     } else if (scheduler_->flags_ & Scheduler::kSplitNodes) {
       // Split the {node} if beneficial and return the new {block} for it.
       block = SplitNode(block, node);
     }
 
     // Schedule the node or a floating control structure.
-    if (NodeProperties::IsControl(node)) {
+    if (IrOpcode::IsMergeOpcode(node->opcode())) {
       ScheduleFloatingControl(block, node);
     } else {
       ScheduleNode(block, node);
     }
   }
 
   // Mark {block} and push its non-marked predecessor on the marking queue.
   void MarkBlock(BasicBlock* block) {
     DCHECK_LT(block->id().ToSize(), marked_.size());
     marked_[block->id().ToSize()] = true;
@@ skipping 103 matching lines @@
     for (Edge edge : node->use_edges()) {
       BasicBlock* use_block = GetBlockForUse(edge);
       block = block == NULL ? use_block : use_block == NULL
                                               ? block
                                               : BasicBlock::GetCommonDominator(
                                                     block, use_block);
     }
     return block;
   }
 
+  BasicBlock* FindPredecessorBlock(Node* node) {
+    return scheduler_->control_flow_builder_->FindPredecessorBlock(node);
+  }
+
   BasicBlock* GetBlockForUse(Edge edge) {
     Node* use = edge.from();
-    IrOpcode::Value opcode = use->opcode();
-    if (IrOpcode::IsPhiOpcode(opcode)) {
+    if (IrOpcode::IsPhiOpcode(use->opcode())) {
       // If the use is from a coupled (i.e. floating) phi, compute the common
       // dominator of its uses. This will not recurse more than one level.
       if (scheduler_->GetPlacement(use) == Scheduler::kCoupled) {
         Trace("  inspecting uses of coupled #%d:%s\n", use->id(),
               use->op()->mnemonic());
         DCHECK_EQ(edge.to(), NodeProperties::GetControlInput(use));
         return GetCommonDominatorOfUses(use);
       }
-      // If the use is from a fixed (i.e. non-floating) phi, use the block
-      // of the corresponding control input to the merge.
+      // If the use is from a fixed (i.e. non-floating) phi, we use the
+      // predecessor block of the corresponding control input to the merge.
       if (scheduler_->GetPlacement(use) == Scheduler::kFixed) {
         Trace("  input@%d into a fixed phi #%d:%s\n", edge.index(), use->id(),
               use->op()->mnemonic());
         Node* merge = NodeProperties::GetControlInput(use, 0);
-        opcode = merge->opcode();
-        DCHECK(opcode == IrOpcode::kMerge || opcode == IrOpcode::kLoop);
-        use = NodeProperties::GetControlInput(merge, edge.index());
+        DCHECK(IrOpcode::IsMergeOpcode(merge->opcode()));
+        Node* input = NodeProperties::GetControlInput(merge, edge.index());
+        return FindPredecessorBlock(input);
+      }
+    } else if (IrOpcode::IsMergeOpcode(use->opcode())) {
+      // If the use is from a fixed (i.e. non-floating) merge, we use the
+      // predecessor block of the current input to the merge.
+      if (scheduler_->GetPlacement(use) == Scheduler::kFixed) {
+        Trace("  input@%d into a fixed merge #%d:%s\n", edge.index(), use->id(),
+              use->op()->mnemonic());
+        return FindPredecessorBlock(edge.to());
       }
     }
     BasicBlock* result = schedule_->block(use);
     if (result == NULL) return NULL;
     Trace("  must dominate use #%d:%s in B%d\n", use->id(),
           use->op()->mnemonic(), result->id().ToInt());
     return result;
   }
 
   void ScheduleFloatingControl(BasicBlock* block, Node* node) {
@@ skipping 128 matching lines @@
   for (Node* const node : *nodes) {
     schedule_->SetBlockForNode(to, node);
     scheduled_nodes_[to->id().ToSize()].push_back(node);
   }
   nodes->clear();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8