Allow Turbofan optimization of Ignition generators

src/compiler/bytecode-graph-builder.cc

 // Copyright 2015 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/bytecode-graph-builder.h"
 
 #include "src/compiler/bytecode-branch-analysis.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/operator-properties.h"
 #include "src/interpreter/bytecodes.h"
@@ skipping 1349 matching lines @@
 
 void BytecodeGraphBuilder::VisitForInStep() {
   FrameStateBeforeAndAfter states(this);
   Node* index =
       environment()->LookupRegister(bytecode_iterator().GetRegisterOperand(0));
   index = NewNode(javascript()->ForInStep(), index);
   environment()->BindAccumulator(index, &states);
 }
 
 void BytecodeGraphBuilder::VisitSuspendGenerator() {
-  UNIMPLEMENTED();
+  Node* state = environment()->LookupAccumulator();
+  Node* generator = environment()->LookupRegister(
+      bytecode_iterator().GetRegisterOperand(0));
+
+  for (int i = 0; i < environment()->register_count(); ++i) {
+    NewNode(javascript()->CallRuntime(Runtime::kGeneratorWriteRegister),

[Benedikt Meurer, 2016/05/10 10:32:08]

Nit: use StoreRegister or SetRegister instead of WriteRegister

[neis, 2016/05/10 11:32:06]

Done.

+        generator, jsgraph()->Constant(i),
+        environment()->LookupRegister(interpreter::Register(i)));

[Michael Starzinger, 2016/05/10 10:53:05]

nit: Better pull out the
"environment()->LookupRegister(interpreter::Register(i)" into a local variable.
The NewNode function can mutate the current environment and this pattern looks
dangerous. In this case evaluation order should be fine, but I'd prefer to
explicitly sequence it.

[neis, 2016/05/10 11:32:06]

Done.

+  }
+
+  NewNode(javascript()->CallRuntime(Runtime::kGeneratorSetContext), generator);
+  NewNode(javascript()->CallRuntime(Runtime::kGeneratorSetContinuation),
+      generator, state);
 }
 
 void BytecodeGraphBuilder::VisitResumeGenerator() {
-  UNIMPLEMENTED();
+  FrameStateBeforeAndAfter states(this);
+
+  Node* generator = environment()->LookupRegister(
+      bytecode_iterator().GetRegisterOperand(0));
+  Node* state = NewNode(javascript()->CallRuntime(
+      Runtime::kGeneratorGetContinuation), generator);
+
+  // Bijection between registers and array indices must match that used in
+  // InterpreterAssembler::ExportRegisterFile.
+  for (int i = 0; i < environment()->register_count(); ++i) {
+    Node* value = NewNode(
+        javascript()->CallRuntime(Runtime::kGeneratorReadRegister),

[Benedikt Meurer, 2016/05/10 10:32:08]

Nit: use LoadRegister instead of ReadRegister

[neis, 2016/05/10 11:32:06]

Done.

+        generator, jsgraph()->Constant(i));
+    environment()->BindRegister(interpreter::Register(i), value);
+
+    NewNode(javascript()->CallRuntime(Runtime::kGeneratorWriteRegister),
+        generator, jsgraph()->Constant(i), jsgraph()->StaleRegisterConstant());
+  }
+
+  NewNode(javascript()->CallRuntime(Runtime::kGeneratorSetContinuation),
+      generator, jsgraph()->Constant(JSGeneratorObject::kGeneratorExecuting));
+
+  environment()->BindAccumulator(state, &states);
 }
 
 void BytecodeGraphBuilder::VisitWide() {
   // Consumed by the BytecodeArrayIterator.
   UNREACHABLE();
 }
 
 void BytecodeGraphBuilder::VisitExtraWide() {
   // Consumed by the BytecodeArrayIterator.
   UNREACHABLE();
 }
 
 void BytecodeGraphBuilder::VisitIllegal() {
-  // Never present in valid bytecode.
-  UNREACHABLE();
+  NewNode(javascript()->CallRuntime(Runtime::kAbort),
+      jsgraph()->Constant(kIllegalBytecode));
 }
 
 void BytecodeGraphBuilder::SwitchToMergeEnvironment(int current_offset) {
   if (merge_environments_[current_offset] != nullptr) {
     if (environment() != nullptr) {
       merge_environments_[current_offset]->Merge(environment());
     }
     set_environment(merge_environments_[current_offset]);
   }
 }
@@ skipping 254 matching lines @@
     // Phi does not exist yet, introduce one.
     value = NewPhi(inputs, value, control);
     value->ReplaceInput(inputs - 1, other);
   }
   return value;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8