[interpreter] Implement OSR graph construction from bytecode.

src/compiler.cc

Index: src/compiler.cc
diff --git a/src/compiler.cc b/src/compiler.cc
index 9b59aca2e4d9da62a68b4600ce26c7db8b7f1c82..42c8bd89e9d1eba648a5444bc2b085e40b6a762a 100644
--- a/src/compiler.cc
+++ b/src/compiler.cc
@@ -585,6 +585,10 @@ void InsertCodeIntoOptimizedCodeMap(CompilationInfo* info) {
   // Frame specialization implies function context specialization.
   DCHECK(!info->is_frame_specializing());
 
+  // TODO(4764): When compiling for OSR from bytecode, BailoutId might derive
+  // from bytecode offset and overlap with actual BailoutId. No caching!
+  if (info->is_osr() && info->is_optimizing_from_bytecode()) return;
+
   // Cache optimized context-specific code.
   Handle<JSFunction> function = info->closure();
   Handle<SharedFunctionInfo> shared(function->shared());
@@ -745,13 +749,15 @@ MaybeHandle<Code> GetOptimizedCode(Handle<JSFunction> function,
   Isolate* isolate = function->GetIsolate();
   Handle<SharedFunctionInfo> shared(function->shared(), isolate);
 
-  // TODO(4764): Remove this guard once OSR graph construction works.
-  if (!osr_ast_id.IsNone() && osr_frame->is_interpreted()) {
-    return MaybeHandle<Code>();
-  }
+  // TODO(4764): When compiling for OSR from bytecode, BailoutId might derive
+  // from bytecode offset and overlap with actual BailoutId. No lookup!

[rmcilroy, 2016/07/26 11:23:37]

This comment should maybe be in the if below?

[Michael Starzinger, 2016/07/26 14:43:15]

Done.

+  bool ignition_osr = !osr_ast_id.IsNone() && osr_frame->is_interpreted();

[rmcilroy, 2016/07/26 11:23:37]

Should this check just be osr_frame->is_interpreted() with a:
DCHECK_IMPLIES(ignition_osr, !osr_ast_id.IsNone()) ?

[Michael Starzinger, 2016/07/26 14:43:15]

Done. As discussed offline, we still need to check that {osr_frame != nullptr}
to filter out the non-OSR case.

+  DCHECK_IMPLIES(ignition_osr, FLAG_ignition_osr);  // Only when enabled.
+  if (ignition_osr && !FLAG_turbo_from_bytecode) return MaybeHandle<Code>();

[rmcilroy, 2016/07/26 11:23:37]

nit - newline above to make this bailout clear.

[Michael Starzinger, 2016/07/26 14:43:15]

Done. Also added a comment explaining this bailout.

 
   Handle<Code> cached_code;
-  if (GetCodeFromOptimizedCodeMap(function, osr_ast_id)
+  if (!ignition_osr &&
+      GetCodeFromOptimizedCodeMap(function, osr_ast_id)
           .ToHandle(&cached_code)) {
     if (FLAG_trace_opt) {
       PrintF("[found optimized code for ");
@@ -772,7 +778,7 @@ MaybeHandle<Code> GetOptimizedCode(Handle<JSFunction> function,
   VMState<COMPILER> state(isolate);
   DCHECK(!isolate->has_pending_exception());
   PostponeInterruptsScope postpone(isolate);
-  bool use_turbofan = UseTurboFan(shared);
+  bool use_turbofan = UseTurboFan(shared) || ignition_osr;
   std::unique_ptr<CompilationJob> job(
       use_turbofan ? compiler::Pipeline::NewCompilationJob(function)
                    : new HCompilationJob(function));