DBC: Another allocation fast path

runtime/vm/intermediate_language_dbc.cc

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_DBC.
 #if defined(TARGET_ARCH_DBC)
 
 #include "vm/intermediate_language.h"
 
 #include "vm/cpu.h"
@@ skipping 898 matching lines @@
   const Register result = locs()->out(0).reg();  // Result char code is a smi.
   __ StringToCharCode(result, str);
 }
 
 
 EMIT_NATIVE_CODE(AllocateObject,
                  0, Location::RequiresRegister(),
                  LocationSummary::kCall) {
   if (ArgumentCount() == 1) {
     // Allocate with type arguments.
-    __ PushConstant(cls());
-    __ AllocateT();
-    compiler->AddCurrentDescriptor(RawPcDescriptors::kOther,
-                                   Thread::kNoDeoptId,
-                                   token_pos());
-    compiler->RecordSafepoint(locs());
     if (compiler->is_optimizing()) {
+      // If we're optimizing, try a streamlined fastpath.
+      const intptr_t instance_size = cls().instance_size();
+      Isolate* isolate = Isolate::Current();
+      if (Heap::IsAllocatableInNewSpace(instance_size) &&
+          !cls().TraceAllocation(isolate)) {
+        uword tags = 0;
+        tags = RawObject::SizeTag::update(instance_size, tags);
+        ASSERT(cls().id() != kIllegalCid);
+        tags = RawObject::ClassIdTag::update(cls().id(), tags);
+        if (Smi::IsValid(tags)) {
+          const intptr_t tags_kidx = __ AddConstant(
+              Smi::Handle(Smi::New(tags)));
+          __ AllocateTOpt(locs()->out(0).reg(), tags_kidx);
+          __ Nop(cls().type_arguments_field_offset());
+        }
+      }
+      __ PushConstant(cls());
+      __ AllocateT();
+      compiler->AddCurrentDescriptor(RawPcDescriptors::kOther,
+                                     Thread::kNoDeoptId,
+                                     token_pos());
+      compiler->RecordSafepoint(locs());
       __ PopLocal(locs()->out(0).reg());
+    } else {
+      __ PushConstant(cls());
+      __ AllocateT();
+      compiler->AddCurrentDescriptor(RawPcDescriptors::kOther,
+                                     Thread::kNoDeoptId,
+                                     token_pos());
+      compiler->RecordSafepoint(locs());
     }
   } else if (compiler->is_optimizing()) {
     // If we're optimizing, try a streamlined fastpath.
     const intptr_t instance_size = cls().instance_size();
     Isolate* isolate = Isolate::Current();
     if (Heap::IsAllocatableInNewSpace(instance_size) &&
         !cls().TraceAllocation(isolate)) {
       uword tags = 0;
       tags = RawObject::SizeTag::update(instance_size, tags);
       ASSERT(cls().id() != kIllegalCid);
@@ skipping 76 matching lines @@
   compiler->AddCurrentDescriptor(RawPcDescriptors::kOther,
                                  Thread::kNoDeoptId,
                                  token_pos());
 }
 
 
 EMIT_NATIVE_CODE(AllocateUninitializedContext,
                  0, Location::RequiresRegister(),
                  LocationSummary::kCall) {
   ASSERT(compiler->is_optimizing());
+  __ AllocateUninitializedContext(locs()->out(0).reg(),
+                                  num_context_variables());
   __ AllocateContext(num_context_variables());
   compiler->RecordSafepoint(locs());
   compiler->AddCurrentDescriptor(RawPcDescriptors::kOther,
                                  Thread::kNoDeoptId,
                                  token_pos());
   __ PopLocal(locs()->out(0).reg());
 }
 
 
 EMIT_NATIVE_CODE(CloneContext,
@@ skipping 751 matching lines @@
   __ IfULe(length, index);
   compiler->EmitDeopt(deopt_id(),
                       ICData::kDeoptCheckArrayBound,
                       (generalized_ ? ICData::kGeneralized : 0) |
                       (licm_hoisted_ ? ICData::kHoisted : 0));
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_DBC