[turbofan] Remove remnants of code flusher support.

This removes special support in the compilation pipeline to keep alive
unoptimized code for inlined functions (i.e. preventing the code flusher
from clearing it). Now that the code flusher is gone, this is obsolete.

R=jarin@chromium.org

Change-Id: I00361d12f2d17556056d06c10ad19f09a4772cd8
Reviewed-on: https://chromium-review.googlesource.com/517948Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45568}

src/compilation-info.cc

@@ -239,8 +239,7 @@ void CompilationInfo::SetOptimizing() {
 int CompilationInfo::AddInlinedFunction(
     Handle<SharedFunctionInfo> inlined_function, SourcePosition pos) {
   int id = static_cast<int>(inlined_functions_.size());
-  inlined_functions_.push_back(InlinedFunctionHolder(
-      inlined_function, handle(inlined_function->code()), pos));
+  inlined_functions_.push_back(InlinedFunctionHolder(inlined_function, pos));
   return id;
 }
 

src/compilation-info.h

@@ -280,18 +280,11 @@ class V8_EXPORT_PRIVATE CompilationInfo final {
   struct InlinedFunctionHolder {
     Handle<SharedFunctionInfo> shared_info;
 
-    // Root that holds the unoptimized code of the inlined function alive
-    // (and out of reach of code flushing) until we finish compilation.
-    // Do not remove.
-    Handle<Code> inlined_code_object_root;
-
     InliningPosition position;
 
     InlinedFunctionHolder(Handle<SharedFunctionInfo> inlined_shared_info,
-                          Handle<Code> inlined_code_object_root,
                           SourcePosition pos)
-        : shared_info(inlined_shared_info),
-          inlined_code_object_root(inlined_code_object_root) {
+        : shared_info(inlined_shared_info) {
       position.position = pos;
       // initialized when generating the deoptimization literals
       position.inlined_function_id = DeoptimizationInputData::kNotInlinedIndex;

src/compiler/code-generator.cc

@@ -107,16 +107,6 @@ void CodeGenerator::AssembleCode() {
   }
   inlined_function_count_ = deoptimization_literals_.size();
 
-  // Define deoptimization literals for all unoptimized code objects of inlined
-  // functions. This ensures unoptimized code is kept alive by optimized code.
-  for (const CompilationInfo::InlinedFunctionHolder& inlined :
-       info->inlined_functions()) {
-    if (!inlined.shared_info.equals(info->shared_info())) {
-      DefineDeoptimizationLiteral(
-          DeoptimizationLiteral(inlined.inlined_code_object_root));
-    }
-  }
-
   unwinding_info_writer_.SetNumberOfInstructionBlocks(
       code()->InstructionBlockCount());
 

src/compiler/js-inlining.cc

@@ -552,12 +552,6 @@ Reduction JSInliner::ReduceJSCall(Node* node) {
     return NoChange();
   }
 
-  // Remember that we inlined this function. This needs to be called right
-  // after we ensure deoptimization support so that the code flusher
-  // does not remove the code with the deoptimization support.
-  int inlining_id = info_->AddInlinedFunction(
-      shared_info, source_positions_->GetSourcePosition(node));
-
   // ----------------------------------------------------------------
   // After this point, we've made a decision to inline this function.
   // We shall not bailout from inlining if we got here.
@@ -571,6 +565,10 @@ Reduction JSInliner::ReduceJSCall(Node* node) {
   Handle<FeedbackVector> feedback_vector;
   DetermineCallContext(node, context, feedback_vector);
 
+  // Remember that we inlined this function.
+  int inlining_id = info_->AddInlinedFunction(
+      shared_info, source_positions_->GetSourcePosition(node));
+
   // Create the subgraph for the inlinee.
   Node* start;
   Node* end;

src/crankshaft/hydrogen.cc

@@ -7952,12 +7952,6 @@ bool HOptimizedGraphBuilder::TryInline(Handle<JSFunction> target,
     return false;
   }
 
-  // Remember that we inlined this function. This needs to be called right
-  // after the EnsureDeoptimizationSupport call so that the code flusher
-  // does not remove the code with the deoptimization support.
-  int inlining_id = top_info()->AddInlinedFunction(target_info.shared_info(),
-                                                   source_position());
-
   // ----------------------------------------------------------------
   // After this point, we've made a decision to inline this function (so
   // TryInline should always return true).
@@ -7976,6 +7970,10 @@ bool HOptimizedGraphBuilder::TryInline(Handle<JSFunction> target,
     return false;
   }
 
+  // Remember that we inlined this function.
+  int inlining_id = top_info()->AddInlinedFunction(target_info.shared_info(),
+                                                   source_position());
+
   // Save the pending call context. Set up new one for the inlined function.
   // The function state is new-allocated because we need to delete it
   // in two different places.

src/crankshaft/lithium-codegen.cc

@@ -394,15 +394,6 @@ void LCodeGenBase::PopulateDeoptimizationLiteralsWithInlinedFunctions() {
     }
   }
   inlined_function_count_ = deoptimization_literals_.length();
-
-  // Define deoptimization literals for all unoptimized code objects of inlined
-  // functions. This ensures unoptimized code is kept alive by optimized code.
-  for (const CompilationInfo::InlinedFunctionHolder& inlined :
-       info()->inlined_functions()) {
-    if (!inlined.shared_info.is_identical_to(info()->shared_info())) {
-      DefineDeoptimizationLiteral(inlined.inlined_code_object_root);
-    }
-  }
 }
 
 Deoptimizer::DeoptInfo LCodeGenBase::MakeDeoptInfo(