[interpreter] Support on-stack replacement in profiler.

src/runtime-profiler.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/runtime-profiler.h"
 
 #include "src/assembler.h"
 #include "src/ast/scopeinfo.h"
 #include "src/base/platform/platform.h"
 #include "src/bootstrapper.h"
@@ skipping 251 matching lines @@
 
 void RuntimeProfiler::MaybeBaselineIgnition(JSFunction* function) {
   if (function->IsInOptimizationQueue()) return;
 
   SharedFunctionInfo* shared = function->shared();
   int ticks = shared->profiler_ticks();
 
   // TODO(rmcilroy): Also ensure we only OSR top-level code if it is smaller
   // than kMaxToplevelSourceSize.
 
-  if (function->IsMarkedForBaseline() || function->IsMarkedForOptimization() ||
-      function->IsMarkedForConcurrentOptimization() ||
-      function->IsOptimized()) {
-    // TODO(rmcilroy): Support OSR in these cases.
+  if (FLAG_ignition_osr && FLAG_always_osr) {
+    AttemptOnStackReplacement(function, AbstractCode::kMaxLoopNestingMarker);
+    // Fall through and do a normal baseline compile as well.
+  } else if (function->IsMarkedForBaseline() ||
+             function->IsMarkedForOptimization() ||
+             function->IsMarkedForConcurrentOptimization() ||
+             function->IsOptimized()) {
+    // Attempt OSR if we are still running interpreted code even though the
+    // the function has long been marked or even already been optimized.
+    int ticks = shared->profiler_ticks();

[rmcilroy, 2016/07/28 16:19:21]

no need for this - just use ticks which is already read above

[Michael Starzinger, 2016/07/28 17:57:24]

Done.

+    int64_t allowance =
+        kOSRCodeSizeAllowanceBase +
+        static_cast<int64_t>(ticks) * kOSRCodeSizeAllowancePerTick;

[rmcilroy, 2016/07/28 16:19:21]

kOSRCodeSizeAllowanceBase and kOSRCodeSizeAllowancePerTick are based on
FullCodeGenerator::kCodeSizeMultiplier. We should probably base this on  the
kCodeSizeMultiplier used by Interpreter::InterruptBudget(), which is sized to
make bytecode equivalent to the multiplied FCG code size.

[Michael Starzinger, 2016/07/28 17:57:24]

Done.

+    if (FLAG_ignition_osr && shared->HasBytecodeArray() &&
+        shared->bytecode_array()->Size() <= allowance) {
+      AttemptOnStackReplacement(function);
+    }
     return;
   }
 
   if (shared->optimization_disabled() &&
       shared->disable_optimization_reason() == kOptimizationDisabledForTest) {
     // Don't baseline functions which have been marked by NeverOptimizeFunction
     // in a test.
     return;
   }
 
   if (ticks >= kProfilerTicksBeforeBaseline) {
     Baseline(function, "hot enough for baseline");
   }
 }
 
 void RuntimeProfiler::MaybeOptimizeIgnition(JSFunction* function) {
   if (function->IsInOptimizationQueue()) return;
 
   SharedFunctionInfo* shared = function->shared();
   int ticks = shared->profiler_ticks();
 
   // TODO(rmcilroy): Also ensure we only OSR top-level code if it is smaller
   // than kMaxToplevelSourceSize.
-  if (function->IsMarkedForBaseline() || function->IsMarkedForOptimization() ||
-      function->IsMarkedForConcurrentOptimization() ||
-      function->IsOptimized()) {
-    // TODO(rmcilroy): Support OSR in these cases.
+
+  if (FLAG_ignition_osr && FLAG_always_osr) {
+    AttemptOnStackReplacement(function, AbstractCode::kMaxLoopNestingMarker);
+    // Fall through and do a normal optimized compile as well.
+  } else if (function->IsMarkedForBaseline() ||
+             function->IsMarkedForOptimization() ||
+             function->IsMarkedForConcurrentOptimization() ||
+             function->IsOptimized()) {
+    // Attempt OSR if we are still running interpreted code even though the
+    // the function has long been marked or even already been optimized.
+    int ticks = shared->profiler_ticks();
+    int64_t allowance =
+        kOSRCodeSizeAllowanceBase +
+        static_cast<int64_t>(ticks) * kOSRCodeSizeAllowancePerTick;
+    if (FLAG_ignition_osr && shared->HasBytecodeArray() &&
+        shared->bytecode_array()->Size() <= allowance) {
+      AttemptOnStackReplacement(function);
+    }
     return;
   }
 
   if (shared->optimization_disabled()) {
     if (shared->deopt_count() >= FLAG_max_opt_count) {
       // If optimization was disabled due to many deoptimizations,
       // then check if the function is hot and try to reenable optimization.
       if (ticks >= kProfilerTicksBeforeReenablingOptimization) {
         shared->set_profiler_ticks(0);
         shared->TryReenableOptimization();
@@ skipping 69 matching lines @@
       DCHECK_EQ(next_tier, Compiler::OPTIMIZED);
       MaybeOptimizeFullCodegen(function, frame_count, frame->is_optimized());
     }
   }
   any_ic_changed_ = false;
 }
 
 
 }  // namespace internal
 }  // namespace v8