[interpreter] Implement OSR graph construction from bytecode.

src/compiler.cc

 // Copyright 2012 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.h"
 
 #include <algorithm>
 #include <memory>
 
 #include "src/asmjs/asm-js.h"
@@ skipping 567 matching lines @@
 void InsertCodeIntoOptimizedCodeMap(CompilationInfo* info) {
   Handle<Code> code = info->code();
   if (code->kind() != Code::OPTIMIZED_FUNCTION) return;  // Nothing to do.
 
   // Function context specialization folds-in the function context,
   // so no sharing can occur.
   if (info->is_function_context_specializing()) return;
   // 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());
   Handle<LiteralsArray> literals(function->literals());
   Handle<Context> native_context(function->context()->native_context());
   SharedFunctionInfo::AddToOptimizedCodeMap(shared, native_context, code,
                                             literals, info->osr_ast_id());
 
   // Do not cache (native) context-independent code compiled for OSR.
   if (code->is_turbofanned() && info->is_osr()) return;
@@ skipping 140 matching lines @@
   return true;
 }
 
 MaybeHandle<Code> GetOptimizedCode(Handle<JSFunction> function,
                                    Compiler::ConcurrencyMode mode,
                                    BailoutId osr_ast_id = BailoutId::None(),
                                    JavaScriptFrame* osr_frame = nullptr) {
   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 ");
       function->ShortPrint();
       if (!osr_ast_id.IsNone()) {
         PrintF(" at OSR AST id %d", osr_ast_id.ToInt());
       }
       PrintF("]\n");
     }
     return cached_code;
   }
 
   // Reset profiler ticks, function is no longer considered hot.
   if (shared->is_compiled()) {
     shared->code()->set_profiler_ticks(0);
   }
 
   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));
   CompilationInfo* info = job->info();
   ParseInfo* parse_info = info->parse_info();
 
   info->SetOptimizingForOsr(osr_ast_id, osr_frame);
 
   // Do not use Crankshaft/TurboFan if we need to be able to set break points.
   if (info->shared_info()->HasDebugInfo()) {
@@ skipping 1130 matching lines @@
     DCHECK(shared->is_compiled());
     function->set_literals(cached.literals);
   } else if (shared->is_compiled()) {
     // TODO(mvstanton): pass pretenure flag to EnsureLiterals.
     JSFunction::EnsureLiterals(function);
   }
 }
 
 }  // namespace internal
 }  // namespace v8