[turbofan] Get rid of SourcePositionInstruction.

src/compiler/instruction-selector.cc

 // Copyright 2014 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/instruction-selector.h"
 
 #include <limits>
 
 #include "src/compiler/instruction-selector-impl.h"
 #include "src/compiler/node-matchers.h"
@@ skipping 457 matching lines @@
   for (BasicBlock::reverse_iterator i = block->rbegin(); i != block->rend();
        ++i) {
     Node* node = *i;
     // Skip nodes that are unused or already defined.
     if (!IsUsed(node) || IsDefined(node)) continue;
     // Generate code for this node "top down", but schedule the code "bottom
     // up".
     size_t current_node_end = instructions_.size();
     VisitNode(node);
     std::reverse(instructions_.begin() + current_node_end, instructions_.end());
+    if (instructions_.size() == current_node_end) continue;
+    // Mark source position on first instruction emitted.
+    SourcePosition source_position = source_positions_->GetSourcePosition(node);
+    if (source_position.IsUnknown()) continue;
+    DCHECK(!source_position.IsInvalid());
+    if (FLAG_turbo_source_positions || node->opcode() == IrOpcode::kCall) {
+      sequence()->SetSourcePosition(instructions_[current_node_end],
+                                    source_position);
+    }
   }
 
   // We're done with the block.
   InstructionBlock* instruction_block =
       sequence()->InstructionBlockAt(RpoNumber::FromInt(block->rpo_number()));
   instruction_block->set_code_start(static_cast<int>(instructions_.size()));
   instruction_block->set_code_end(current_block_end);
 
   current_block_ = NULL;
 }
@@ skipping 86 matching lines @@
     }
     default:
       UNREACHABLE();
       break;
   }
 }
 
 
 void InstructionSelector::VisitNode(Node* node) {
   DCHECK_NOT_NULL(schedule()->block(node));  // should only use scheduled nodes.
-  SourcePosition source_position = source_positions_->GetSourcePosition(node);
-  if (!source_position.IsUnknown()) {
-    DCHECK(!source_position.IsInvalid());
-    if (FLAG_turbo_source_positions || node->opcode() == IrOpcode::kCall) {
-      Emit(SourcePositionInstruction::New(instruction_zone(), source_position));
-    }
-  }
   switch (node->opcode()) {
     case IrOpcode::kStart:
     case IrOpcode::kLoop:
     case IrOpcode::kEnd:
     case IrOpcode::kBranch:
     case IrOpcode::kIfTrue:
     case IrOpcode::kIfFalse:
     case IrOpcode::kIfSuccess:
     case IrOpcode::kSwitch:
     case IrOpcode::kIfValue:
@@ skipping 597 matching lines @@
 MachineOperatorBuilder::Flags
 InstructionSelector::SupportedMachineOperatorFlags() {
   return MachineOperatorBuilder::Flag::kNoFlags;
 }
 
 #endif  // !V8_TURBOFAN_BACKEND
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8