[wasm] Trim graph before scheduling.

src/compiler/pipeline.cc

 // Copyright 2014 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/pipeline.h"
 
 #include <fstream>  // NOLINT(readability/streams)
 #include <memory>
 #include <sstream>
 
@@ skipping 371 matching lines @@
 
   // Run the graph creation and initial optimization passes.
   bool CreateGraph();
 
   // Run the concurrent optimization passes.
   bool OptimizeGraph(Linkage* linkage);
 
   // Perform the actual code generation and return handle to a code object.
   Handle<Code> GenerateCode(Linkage* linkage);
 
-  bool ScheduleAndSelectInstructions(Linkage* linkage);
+  bool ScheduleAndSelectInstructions(Linkage* linkage, bool trim_graph);
   void RunPrintAndVerify(const char* phase, bool untyped = false);
   Handle<Code> ScheduleAndGenerateCode(CallDescriptor* call_descriptor);
   void AllocateRegisters(const RegisterConfiguration* config,
                          CallDescriptor* descriptor, bool run_verifier);
 
   CompilationInfo* info() const;
   Isolate* isolate() const;
 
   PipelineData* const data_;
 };
@@ skipping 282 matching lines @@
 PipelineWasmCompilationJob::Status
 PipelineWasmCompilationJob::ExecuteJobImpl() {
   if (FLAG_trace_turbo) {
     TurboJsonFile json_of(info(), std::ios_base::trunc);
     json_of << "{\"function\":\"" << info()->GetDebugName().get()
             << "\", \"source\":\"\",\n\"phases\":[";
   }
 
   pipeline_.RunPrintAndVerify("Machine", true);
 
-  if (!pipeline_.ScheduleAndSelectInstructions(&linkage_)) return FAILED;
+  if (!pipeline_.ScheduleAndSelectInstructions(&linkage_, true)) return FAILED;
   return SUCCEEDED;
 }
 
 PipelineWasmCompilationJob::Status
 PipelineWasmCompilationJob::FinalizeJobImpl() {
   pipeline_.GenerateCode(&linkage_);
   return SUCCEEDED;
 }
 
 template <typename Phase>
@@ skipping 493 matching lines @@
     trimmer.TrimGraph(roots.begin(), roots.end());
   }
 };
 
 
 struct LateGraphTrimmingPhase {
   static const char* phase_name() { return "late graph trimming"; }
   void Run(PipelineData* data, Zone* temp_zone) {
     GraphTrimmer trimmer(temp_zone, data->graph());
     NodeVector roots(temp_zone);
-    data->jsgraph()->GetCachedNodes(&roots);
+    if (data->jsgraph()) {
+      data->jsgraph()->GetCachedNodes(&roots);
+    }
     trimmer.TrimGraph(roots.begin(), roots.end());
   }
 };
 
 
 struct StressLoopPeelingPhase {
   static const char* phase_name() { return "stress loop peeling"; }
 
   void Run(PipelineData* data, Zone* temp_zone) {
     // Peel the first outer loop for testing.
@@ skipping 421 matching lines @@
   // Optimize memory access and allocation operations.
   Run<MemoryOptimizationPhase>();
   // TODO(jarin, rossberg): Remove UNTYPED once machine typing works.
   RunPrintAndVerify("Memory optimized", true);
 
   // Lower changes that have been inserted before.
   Run<LateOptimizationPhase>();
   // TODO(jarin, rossberg): Remove UNTYPED once machine typing works.
   RunPrintAndVerify("Late optimized", true);
 
-  Run<LateGraphTrimmingPhase>();
-  // TODO(jarin, rossberg): Remove UNTYPED once machine typing works.
-  RunPrintAndVerify("Late trimmed", true);
+  //  Run<LateGraphTrimmingPhase>();

[Benedikt Meurer, 2016/10/17 07:18:46]

Nit: Remove this dead code then.

[ahaas, 2016/10/17 07:23:57]

Done

[Benedikt Meurer, 2016/10/17 08:38:14]

Thx!

+  //  // TODO(jarin, rossberg): Remove UNTYPED once machine typing works.
+  //  RunPrintAndVerify("Late trimmed", true);
 
   data->source_positions()->RemoveDecorator();
 
-  return ScheduleAndSelectInstructions(linkage);
+  return ScheduleAndSelectInstructions(linkage, true);
 }
 
 Handle<Code> Pipeline::GenerateCodeForCodeStub(Isolate* isolate,
                                                CallDescriptor* call_descriptor,
                                                Graph* graph, Schedule* schedule,
                                                Code::Flags flags,
                                                const char* debug_name) {
   CompilationInfo info(CStrVector(debug_name), isolate, graph->zone(), flags);
   if (isolate->serializer_enabled()) info.PrepareForSerializing();
 
@@ skipping 92 matching lines @@
   CompilationInfo info(ArrayVector("testing"), sequence->isolate(),
                        sequence->zone(), Code::ComputeFlags(Code::STUB));
   ZoneStats zone_stats(sequence->isolate()->allocator());
   PipelineData data(&zone_stats, &info, sequence);
   PipelineImpl pipeline(&data);
   pipeline.data_->InitializeFrameData(nullptr);
   pipeline.AllocateRegisters(config, nullptr, run_verifier);
   return !data.compilation_failed();
 }
 
-bool PipelineImpl::ScheduleAndSelectInstructions(Linkage* linkage) {
+bool PipelineImpl::ScheduleAndSelectInstructions(Linkage* linkage,
+                                                 bool trim_graph) {
   CallDescriptor* call_descriptor = linkage->GetIncomingDescriptor();
   PipelineData* data = this->data_;
 
   DCHECK_NOT_NULL(data->graph());
 
+  if (trim_graph) {
+    Run<LateGraphTrimmingPhase>();
+    RunPrintAndVerify("Late trimmed", true);
+  }
   if (data->schedule() == nullptr) Run<ComputeSchedulePhase>();
   TraceSchedule(data->info(), data->schedule());
 
   if (FLAG_turbo_profiling) {
     data->set_profiler_data(BasicBlockInstrumentor::Instrument(
         info(), data->graph(), data->schedule()));
   }
 
   if (FLAG_turbo_verify_machine_graph != nullptr &&
       (!strcmp(FLAG_turbo_verify_machine_graph, "*") ||
@@ skipping 102 matching lines @@
   }
 
   return code;
 }
 
 Handle<Code> PipelineImpl::ScheduleAndGenerateCode(
     CallDescriptor* call_descriptor) {
   Linkage linkage(call_descriptor);
 
   // Schedule the graph, perform instruction selection and register allocation.
-  if (!ScheduleAndSelectInstructions(&linkage)) return Handle<Code>();
+  if (!ScheduleAndSelectInstructions(&linkage, false)) return Handle<Code>();
 
   // Generate the final machine code.
   return GenerateCode(&linkage);
 }
 
 void PipelineImpl::AllocateRegisters(const RegisterConfiguration* config,
                                      CallDescriptor* descriptor,
                                      bool run_verifier) {
   PipelineData* data = this->data_;
   // Don't track usage for this zone in compiler stats.
@@ skipping 79 matching lines @@
   data->DeleteRegisterAllocationZone();
 }
 
 CompilationInfo* PipelineImpl::info() const { return data_->info(); }
 
 Isolate* PipelineImpl::isolate() const { return info()->isolate(); }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8