Add support for OSR in kernel-based FlowGraphBuilder

runtime/vm/kernel_to_il.cc

Index: runtime/vm/kernel_to_il.cc
diff --git a/runtime/vm/kernel_to_il.cc b/runtime/vm/kernel_to_il.cc
index 0aff92bde22c049fe019ecf25664c11b8a31faf7..bc8fbf0554fa8658546a958330f4427640c28ad0 100644
--- a/runtime/vm/kernel_to_il.cc
+++ b/runtime/vm/kernel_to_il.cc
@@ -2647,6 +2647,19 @@ void FlowGraphBuilder::InlineBailout(const char* reason) {
 }
 
 
+void FlowGraphBuilder::PruneUnreachableIfOSR() {
+  // When compiling for OSR, use a depth first search to prune instructions
+  // unreachable from the OSR entry. Catch entries are always considered
+  // reachable, even if they become unreachable after OSR.
+  if (osr_id_ != Compiler::kNoOSRDeoptId) {
+    BitVector* block_marks = new(Z) BitVector(Z, next_block_id_);
+    bool found = graph_entry_->PruneUnreachable(graph_entry_, NULL, osr_id_,
+                                                block_marks);
+    ASSERT(found);
+  }
+}
+
+
 FlowGraph* FlowGraphBuilder::BuildGraph() {
   const dart::Function& function = parsed_function_->function();
 
@@ -2750,7 +2763,7 @@ FlowGraph* FlowGraphBuilder::BuildGraphOfFunction(FunctionNode* function,
   const Function& dart_function = parsed_function_->function();
   TargetEntryInstr* normal_entry = BuildTargetEntry();
   graph_entry_ = new (Z)
-      GraphEntryInstr(*parsed_function_, normal_entry, Compiler::kNoOSRDeoptId);
+      GraphEntryInstr(*parsed_function_, normal_entry, osr_id_);
 
   SetupDefaultParameterValues(function);
 
@@ -2917,6 +2930,7 @@ FlowGraph* FlowGraphBuilder::BuildGraphOfFunction(FunctionNode* function,
   }
   normal_entry->LinkTo(body.entry);
 
+  PruneUnreachableIfOSR();

[Vyacheslav Egorov (Google), 2016/10/31 17:46:37]

I think  only this one can OSR - inline the function here.

[kustermann, 2016/10/31 18:18:13]

Done.

   return new (Z) FlowGraph(*parsed_function_, graph_entry_, next_block_id_ - 1);
 }
 
@@ -3088,7 +3102,7 @@ FlowGraph* FlowGraphBuilder::BuildGraphOfFieldAccessor(
 
   TargetEntryInstr* normal_entry = BuildTargetEntry();
   graph_entry_ = new (Z)
-      GraphEntryInstr(*parsed_function_, normal_entry, Compiler::kNoOSRDeoptId);
+      GraphEntryInstr(*parsed_function_, normal_entry, osr_id_);
 
   // TODO(27590): Add support for FLAG_use_field_guards.
   Fragment body(normal_entry);
@@ -3126,6 +3140,7 @@ FlowGraph* FlowGraphBuilder::BuildGraphOfFieldAccessor(
   }
   body += Return();
 
+  PruneUnreachableIfOSR();

[Vyacheslav Egorov (Google), 2016/10/31 17:46:37]

I don't think this and below can be OSRed.

[kustermann, 2016/10/31 18:18:13]

Done.

   return new (Z) FlowGraph(*parsed_function_, graph_entry_, next_block_id_ - 1);
 }
 
@@ -3138,7 +3153,7 @@ FlowGraph* FlowGraphBuilder::BuildGraphOfStaticFieldInitializer(
 
   TargetEntryInstr* normal_entry = BuildTargetEntry();
   graph_entry_ = new (Z)
-      GraphEntryInstr(*parsed_function_, normal_entry, Compiler::kNoOSRDeoptId);
+      GraphEntryInstr(*parsed_function_, normal_entry, osr_id_);
 
   Fragment body(normal_entry);
   body += CheckStackOverflowInPrologue();
@@ -3149,6 +3164,7 @@ FlowGraph* FlowGraphBuilder::BuildGraphOfStaticFieldInitializer(
   }
   body += Return();
 
+  PruneUnreachableIfOSR();
   return new (Z) FlowGraph(*parsed_function_, graph_entry_, next_block_id_ - 1);
 }
 
@@ -3192,12 +3208,13 @@ FlowGraph* FlowGraphBuilder::BuildGraphOfMethodExtractor(
 
   TargetEntryInstr* normal_entry = BuildTargetEntry();
   graph_entry_ = new (Z)
-      GraphEntryInstr(*parsed_function_, normal_entry, Compiler::kNoOSRDeoptId);
+      GraphEntryInstr(*parsed_function_, normal_entry, osr_id_);
   Fragment body(normal_entry);
   body += CheckStackOverflowInPrologue();
   body += BuildImplicitClosureCreation(function);
   body += Return();
 
+  PruneUnreachableIfOSR();
   return new (Z) FlowGraph(*parsed_function_, graph_entry_, next_block_id_ - 1);
 }
 
@@ -3208,7 +3225,7 @@ FlowGraph* FlowGraphBuilder::BuildGraphOfImplicitClosureFunction(
 
   TargetEntryInstr* normal_entry = BuildTargetEntry();
   graph_entry_ = new (Z)
-      GraphEntryInstr(*parsed_function_, normal_entry, Compiler::kNoOSRDeoptId);
+      GraphEntryInstr(*parsed_function_, normal_entry, osr_id_);
   SetupDefaultParameterValues(kernel_function);
 
   Fragment body(normal_entry);
@@ -3248,6 +3265,7 @@ FlowGraph* FlowGraphBuilder::BuildGraphOfImplicitClosureFunction(
   // Return the result.
   body += Return();
 
+  PruneUnreachableIfOSR();
   return new (Z) FlowGraph(*parsed_function_, graph_entry_, next_block_id_ - 1);
 }
 
@@ -3259,7 +3277,7 @@ FlowGraph* FlowGraphBuilder::BuildGraphOfNoSuchMethodDispatcher(
 
   TargetEntryInstr* normal_entry = BuildTargetEntry();
   graph_entry_ = new (Z)
-      GraphEntryInstr(*parsed_function_, normal_entry, Compiler::kNoOSRDeoptId);
+      GraphEntryInstr(*parsed_function_, normal_entry, osr_id_);
 
   // The backend will expect an array of default values for all the named
   // parameters, even if they are all known to be passed at the call site
@@ -3349,6 +3367,7 @@ FlowGraph* FlowGraphBuilder::BuildGraphOfNoSuchMethodDispatcher(
   body += StaticCall(no_such_method, 2);
   body += Return();
 
+  PruneUnreachableIfOSR();
   return new (Z) FlowGraph(*parsed_function_, graph_entry_, next_block_id_ - 1);
 }
 
@@ -3393,7 +3412,7 @@ FlowGraph* FlowGraphBuilder::BuildGraphOfInvokeFieldDispatcher(
 
   TargetEntryInstr* normal_entry = BuildTargetEntry();
   graph_entry_ = new (Z)
-      GraphEntryInstr(*parsed_function_, normal_entry, Compiler::kNoOSRDeoptId);
+      GraphEntryInstr(*parsed_function_, normal_entry, osr_id_);
 
   Fragment body(normal_entry);
   body += CheckStackOverflowInPrologue();
@@ -3435,6 +3454,7 @@ FlowGraph* FlowGraphBuilder::BuildGraphOfInvokeFieldDispatcher(
 
   body += Return();
 
+  PruneUnreachableIfOSR();
   return new (Z) FlowGraph(*parsed_function_, graph_entry_, next_block_id_ - 1);
 }