[compiler] Ensure code unsupported by Crankshaft goes to Ignition.

src/compiler.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/compiler.h"
 
 #include <algorithm>
 #include <memory>
 
 #include "src/asmjs/asm-js.h"
@@ skipping 287 matching lines @@
   }
 
   // It's very important that recompiles do not alter the structure of the type
   // feedback vector. Verify that the structure fits the function literal.
   CHECK(!info->shared_info()->feedback_metadata()->SpecDiffersFrom(
       info->literal()->feedback_vector_spec()));
 }
 
 bool UseTurboFan(Handle<SharedFunctionInfo> shared) {
   bool optimization_disabled = shared->optimization_disabled();
-  bool dont_crankshaft = shared->dont_crankshaft();
+  bool must_use_ignition_turbo = shared->must_use_ignition_turbo();
 
   // Check the enabling conditions for Turbofan.
   // 1. "use asm" code.
   bool is_turbofanable_asm =
       FLAG_turbo_asm && shared->asm_function() && !optimization_disabled;
 
   // 2. Fallback for features unsupported by Crankshaft.
   bool is_unsupported_by_crankshaft_but_turbofanable =
-      dont_crankshaft && strcmp(FLAG_turbo_filter, "~~") == 0 &&
+      must_use_ignition_turbo && strcmp(FLAG_turbo_filter, "~~") == 0 &&
       !optimization_disabled;
 
   // 3. Explicitly enabled by the command-line filter.
   bool passes_turbo_filter = shared->PassesFilter(FLAG_turbo_filter);
 
   return is_turbofanable_asm || is_unsupported_by_crankshaft_but_turbofanable ||
          passes_turbo_filter;
 }
 
 bool ShouldUseIgnition(CompilationInfo* info) {
   DCHECK(info->has_shared_info());
+  Handle<SharedFunctionInfo> shared = info->shared_info();
+
+  // Code which can't be supported by the old pipeline should use Ignition.
+  if (shared->must_use_ignition_turbo()) return true;
 
   // Resumable functions are not supported by {FullCodeGenerator}, suspended
   // activations stored as {JSGeneratorObject} on the heap always assume the
   // underlying code to be based on the bytecode array.
-  // TODO(mstarzinger): Once we want to deprecate even more support from the
-  // {FullCodeGenerator}, we will compute an appropriate bit in {AstNumbering}
-  // and turn this predicate into a DCHECK instead.
-  if (IsResumableFunction(info->shared_info()->kind())) {
-    return true;
-  }
+  DCHECK(!IsResumableFunction(shared->kind()));
 
   // Skip Ignition for asm.js functions.
-  if (info->shared_info()->asm_function()) {
+  if (shared->asm_function()) return false;
+
+  // Skip Ignition for asm wasm code.
+  if (FLAG_validate_asm && shared->HasAsmWasmData()) {
     return false;
   }
 
   // When requesting debug code as a replacement for existing code, we provide
   // the same kind as the existing code (to prevent implicit tier-change).
-  if (info->is_debug() && info->shared_info()->is_compiled()) {
-    return !info->shared_info()->HasBaselineCode();
+  if (info->is_debug() && shared->is_compiled()) {
+    return !shared->HasBaselineCode();
   }
 
   // Code destined for TurboFan should be compiled with Ignition first.
-  if (UseTurboFan(info->shared_info())) return true;
+  if (UseTurboFan(shared)) return true;
 
   // Only use Ignition for any other function if FLAG_ignition is true.
   if (!FLAG_ignition) return false;
 
   // Checks whether top level functions should be passed by the filter.
-  if (info->shared_info()->is_toplevel()) {
+  if (shared->is_toplevel()) {
     Vector<const char> filter = CStrVector(FLAG_ignition_filter);
     return (filter.length() == 0) || (filter.length() == 1 && filter[0] == '*');
   }
 
   // Finally respect the filter.
-  return info->shared_info()->PassesFilter(FLAG_ignition_filter);
+  return shared->PassesFilter(FLAG_ignition_filter);
 }
 
 CompilationJob* GetUnoptimizedCompilationJob(CompilationInfo* info) {
   // Function should have been parsed and analyzed before creating a compilation
   // job.
   DCHECK_NOT_NULL(info->literal());
   DCHECK_NOT_NULL(info->scope());
 
   EnsureFeedbackMetadata(info);
   if (ShouldUseIgnition(info)) {
@@ skipping 145 matching lines @@
                               parse_info->literal())) {
     return false;
   }
   Handle<SharedFunctionInfo> shared_info = parse_info->shared_info();
   if (!shared_info.is_null()) {
     FunctionLiteral* lit = parse_info->literal();
     shared_info->set_ast_node_count(lit->ast_node_count());
     if (lit->dont_optimize_reason() != kNoReason) {
       shared_info->DisableOptimization(lit->dont_optimize_reason());
     }
-    if (lit->flags() & AstProperties::kDontCrankshaft) {
-      shared_info->set_dont_crankshaft(true);
+    if (lit->flags() & AstProperties::kMustUseIgnitionTurbo) {
+      shared_info->set_must_use_ignition_turbo(true);
     }
   }
   return true;
 }
 
 bool GetOptimizedCodeNow(CompilationJob* job) {
   CompilationInfo* info = job->info();
   Isolate* isolate = info->isolate();
 
   // Parsing is not required when optimizing from existing bytecode.
@@ skipping 101 matching lines @@
       function->ShortPrint();
       if (!osr_ast_id.IsNone()) {
         PrintF(" at OSR AST id %d", osr_ast_id.ToInt());
       }
       PrintF("]\n");
     }
     return cached_code;
   }
 
   // Reset profiler ticks, function is no longer considered hot.
+  DCHECK(shared->is_compiled());
   if (shared->HasBaselineCode()) {
     shared->code()->set_profiler_ticks(0);
   } else if (shared->HasBytecodeArray()) {
     shared->set_profiler_ticks(0);
   }
 
   VMState<COMPILER> state(isolate);
   DCHECK(!isolate->has_pending_exception());
   PostponeInterruptsScope postpone(isolate);
   bool use_turbofan = UseTurboFan(shared) || ignition_osr;
@@ skipping 19 matching lines @@
     return MaybeHandle<Code>();
   }
 
   TimerEventScope<TimerEventOptimizeCode> optimize_code_timer(isolate);
   RuntimeCallTimerScope runtimeTimer(isolate, &RuntimeCallStats::OptimizeCode);
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"), "V8.OptimizeCode");
 
   // TurboFan can optimize directly from existing bytecode.
   if (use_turbofan && ShouldUseIgnition(info)) {
     if (info->is_osr() && !ignition_osr) return MaybeHandle<Code>();
-    if (!Compiler::EnsureBytecode(info)) {
-      if (isolate->has_pending_exception()) isolate->clear_pending_exception();
-      return MaybeHandle<Code>();
-    }
+    DCHECK(shared->HasBytecodeArray());
     info->MarkAsOptimizeFromBytecode();
   }
 
   // Verify that OSR compilations are delegated to the correct graph builder.
   // Depending on the underlying frame the semantics of the {BailoutId} differ
   // and the various graph builders hard-code a certain semantic:
   //  - Interpreter : The BailoutId represents a bytecode offset.
   //  - FullCodegen : The BailoutId represents the id of an AST node.
   DCHECK_IMPLIES(info->is_osr() && ignition_osr,
                  info->is_optimizing_from_bytecode());
@@ skipping 109 matching lines @@
   if (function->shared()->code()->kind() == Code::FUNCTION) {
     return Handle<Code>(function->shared()->code());
   }
 
   // We do not switch to baseline code when the debugger might have created a
   // copy of the bytecode with break slots to be able to set break points.
   if (function->shared()->HasDebugInfo()) {
     return MaybeHandle<Code>();
   }
 
-  // TODO(4280): For now we do not switch generators or async functions to
-  // baseline code because there might be suspended activations stored in
-  // generator objects on the heap. We could eventually go directly to
-  // TurboFan in this case.
-  if (IsResumableFunction(function->shared()->kind())) {
+  // Don't generate full-codegen code for functions it can't support.
+  if (function->shared()->must_use_ignition_turbo()) {
     return MaybeHandle<Code>();
   }
+  DCHECK(!IsResumableFunction(function->shared()->kind()));
 
   if (FLAG_trace_opt) {
     OFStream os(stdout);
     os << "[switching method " << Brief(*function) << " to baseline code]"
        << std::endl;
   }
 
   // Parse and update CompilationInfo with the results.
   if (!Parser::ParseStatic(info.parse_info())) return MaybeHandle<Code>();
   Handle<SharedFunctionInfo> shared = info.shared_info();
@@ skipping 345 matching lines @@
 
   // Restore the original function info list in order to remain side-effect
   // free as much as possible, since some code expects the old shared function
   // infos to stick around.
   script->set_shared_function_infos(*old_function_infos);
 
   return infos;
 }
 
 bool Compiler::EnsureBytecode(CompilationInfo* info) {
-  if (!ShouldUseIgnition(info)) return false;
-  if (!info->shared_info()->HasBytecodeArray()) {
-    Handle<Code> original_code(info->shared_info()->code());
+  if (!info->shared_info()->is_compiled()) {
     if (GetUnoptimizedCode(info).is_null()) return false;
     if (info->shared_info()->HasAsmWasmData()) return false;
-    DCHECK(info->shared_info()->is_compiled());
-    if (original_code->kind() == Code::FUNCTION) {
-      // Generating bytecode will install the {InterpreterEntryTrampoline} as
-      // shared code on the function. To avoid an implicit tier down we restore
-      // original baseline code in case it existed beforehand.
-      info->shared_info()->ReplaceCode(*original_code);
-    }
   }
-  DCHECK(info->shared_info()->HasBytecodeArray());
-  return true;
+  DCHECK(info->shared_info()->is_compiled());
+  DCHECK_EQ(ShouldUseIgnition(info), info->shared_info()->HasBytecodeArray());
+  return info->shared_info()->HasBytecodeArray();
 }
 
 // TODO(turbofan): In the future, unoptimized code with deopt support could
 // be generated lazily once deopt is triggered.
 bool Compiler::EnsureDeoptimizationSupport(CompilationInfo* info) {
   DCHECK_NOT_NULL(info->literal());
   DCHECK_NOT_NULL(info->scope());
   Handle<SharedFunctionInfo> shared = info->shared_info();
   if (!shared->has_deoptimization_support()) {
     Zone zone(info->isolate()->allocator(), ZONE_NAME);
     CompilationInfo unoptimized(info->parse_info(), info->closure());
     unoptimized.EnableDeoptimizationSupport();
 
-    // TODO(4280): For now we do not switch generators or async functions to
-    // baseline code because there might be suspended activations stored in
-    // generator objects on the heap. We could eventually go directly to
-    // TurboFan in this case.
-    if (IsResumableFunction(shared->kind())) return false;
+    // Don't generate full-codegen code for functions it can't support.
+    if (shared->must_use_ignition_turbo()) return false;
+    DCHECK(!IsResumableFunction(shared->kind()));
 
     // When we call PrepareForSerializing below, we will change the shared
     // ParseInfo. Make sure to reset it.
     bool old_will_serialize_value = info->parse_info()->will_serialize();
 
     // If the current code has reloc info for serialization, also include
     // reloc info for serialization for the new code, so that deopt support
     // can be added without losing IC state.
     if (shared->code()->kind() == Code::FUNCTION &&
         shared->code()->has_reloc_info_for_serialization()) {
       unoptimized.PrepareForSerializing();
     }
     EnsureFeedbackMetadata(&unoptimized);
+
+    // Ensure we generate and install bytecode first if the function should use
+    // Ignition to avoid implicit tier-down.
+    if (!shared->is_compiled() && ShouldUseIgnition(info) &&
+        !GenerateUnoptimizedCode(info)) {
+      return false;
+    }
+
     if (!FullCodeGenerator::MakeCode(&unoptimized)) return false;
 
     info->parse_info()->set_will_serialize(old_will_serialize_value);
 
     // The scope info might not have been set if a lazily compiled
     // function is inlined before being called for the first time.
     if (shared->scope_info() == ScopeInfo::Empty(info->isolate())) {
       InstallSharedScopeInfo(info, shared);
     }
 
@@ skipping 454 matching lines @@
       return true;
     }
     return false;
   }
 }
 
 void Compiler::PostInstantiation(Handle<JSFunction> function,
                                  PretenureFlag pretenure) {
   Handle<SharedFunctionInfo> shared(function->shared());
 
-  if (FLAG_always_opt && shared->allows_lazy_compilation()) {
+  if (FLAG_always_opt && shared->allows_lazy_compilation() &&
+      function->shared()->is_compiled()) {
     function->MarkForOptimization();
   }
 
   CodeAndLiterals cached = shared->SearchOptimizedCodeMap(
       function->context()->native_context(), BailoutId::None());
   if (cached.code != nullptr) {
     // Caching of optimized code enabled and optimized code found.
     DCHECK(!cached.code->marked_for_deoptimization());
     DCHECK(function->shared()->is_compiled());
     function->ReplaceCode(cached.code);
   }
 
   if (cached.literals != nullptr) {
     DCHECK(shared->is_compiled());
     function->set_literals(cached.literals);
   } else if (shared->is_compiled()) {
     // TODO(mvstanton): pass pretenure flag to EnsureLiterals.
     JSFunction::EnsureLiterals(function);
   }
 }
 
 }  // namespace internal
 }  // namespace v8