[interpreter] Support on-stack replacement in profiler.

src/runtime-profiler.cc

Index: src/runtime-profiler.cc
diff --git a/src/runtime-profiler.cc b/src/runtime-profiler.cc
index f483c7d06c5fd7632aee1bdbf8c605d7cb1d9ca9..90764194f67f0a40c13ba8d8a1f35be8273b65f8 100644
--- a/src/runtime-profiler.cc
+++ b/src/runtime-profiler.cc
@@ -269,10 +269,23 @@ void RuntimeProfiler::MaybeBaselineIgnition(JSFunction* function) {
   // 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;
   }
 
@@ -296,10 +309,24 @@ void RuntimeProfiler::MaybeOptimizeIgnition(JSFunction* function) {
 
   // 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;
   }