Trace allocation of arrays

runtime/vm/stub_code_mips.cc

 // Copyright (c) 2013, 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"
 #if defined(TARGET_ARCH_MIPS)
 
 #include "vm/assembler.h"
 #include "vm/code_generator.h"
 #include "vm/compiler.h"
@@ skipping 675 matching lines @@
 //   RA: return address.
 //   A1: Array length as Smi (must be preserved).
 //   A0: array element type (either NULL or an instantiated type).
 // NOTE: A1 cannot be clobbered here as the caller relies on it being saved.
 // The newly allocated object is returned in V0.
 void StubCode::GeneratePatchableAllocateArrayStub(Assembler* assembler,
     uword* entry_patch_offset, uword* patch_code_pc_offset) {
   __ Comment("AllocateArrayStub");
   *entry_patch_offset = assembler->CodeSize();
   Label slow_case;
+  Isolate* isolate = Isolate::Current();
+  const Class& cls = Class::Handle(isolate->object_store()->array_class());
+  ASSERT(!cls.IsNull());
 
   // Compute the size to be allocated, it is based on the array length
   // and is computed as:
   // RoundedAllocationSize((array_length * kwordSize) + sizeof(RawArray)).
   __ mov(T3, A1);  // Array length.
 
   // Check that length is a positive Smi.
   __ andi(CMPRES1, T3, Immediate(kSmiTagMask));
-  __ bne(CMPRES1, ZR, &slow_case);
+  if (FLAG_use_slow_path || cls.trace_allocation()) {
+    __ b(&slow_case);
+  } else {
+    __ bne(CMPRES1, ZR, &slow_case);
+  }
   __ bltz(T3, &slow_case);
 
   // Check for maximum allowed length.
   const intptr_t max_len =
       reinterpret_cast<int32_t>(Smi::New(Array::kMaxElements));
   __ BranchUnsignedGreater(T3, Immediate(max_len), &slow_case);
 
   const intptr_t fixed_size = sizeof(RawArray) + kObjectAlignment - 1;
   __ LoadImmediate(T2, fixed_size);
   __ sll(T3, T3, 1);  // T3 is  a Smi.
   __ addu(T2, T2, T3);
   ASSERT(kSmiTagShift == 1);
   __ LoadImmediate(T3, ~(kObjectAlignment - 1));
   __ and_(T2, T2, T3);
 
   // T2: Allocation size.
 
-  Isolate* isolate = Isolate::Current();
   Heap* heap = isolate->heap();
   const intptr_t cid = kArrayCid;
   Heap::Space space = heap->SpaceForAllocation(cid);
   __ LoadImmediate(T3, heap->TopAddress(space));
   __ lw(T0, Address(T3, 0));  // Potential new object start.
 
   __ addu(T1, T0, T2);  // Potential next object start.
   __ BranchUnsignedLess(T1, T0, &slow_case);  // Branch on unsigned overflow.
 
   // Check if the allocation fits into the remaining space.
@@ skipping 1580 matching lines @@
 // Result:
 //  T1: entry point.
 void StubCode::GenerateMegamorphicLookupStub(Assembler* assembler) {
   EmitMegamorphicLookup(assembler, T0, T1, T1);
   __ Ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_MIPS