Adapt Danno's Track Allocation Info idea to fast literals. When allocating a literal array,

src/arm/code-stubs-arm.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 326 matching lines @@
   // Need to collect. Call into runtime system.
   __ bind(&gc);
   __ TailCallRuntime(Runtime::kPushBlockContext, 2, 1);
 }
 
 
 static void GenerateFastCloneShallowArrayCommon(
     MacroAssembler* masm,
     int length,
     FastCloneShallowArrayStub::Mode mode,
+    FastCloneShallowArrayStub::AllocationInfoMode allocation_info_mode,
     Label* fail) {
   // Registers on entry:
   //
   // r3: boilerplate literal array.
   ASSERT(mode != FastCloneShallowArrayStub::CLONE_ANY_ELEMENTS);
 
   // All sizes here are multiples of kPointerSize.
   int elements_size = 0;
   if (length > 0) {
     elements_size = mode == FastCloneShallowArrayStub::CLONE_DOUBLE_ELEMENTS
         ? FixedDoubleArray::SizeFor(length)
         : FixedArray::SizeFor(length);
   }
-  int size = JSArray::kSize + elements_size;
+  int size = JSArray::kSize;
+  int allocation_info_start = size;
+  if (allocation_info_mode ==
+      FastCloneShallowArrayStub::TRACK_ALLOCATION_INFO) {
+    size += AllocationSiteInfo::kSize;
+  }
+  size += elements_size;
 
   // Allocate both the JS array and the elements array in one big
   // allocation. This avoids multiple limit checks.
   AllocationFlags flags = TAG_OBJECT;
   if (mode == FastCloneShallowArrayStub::CLONE_DOUBLE_ELEMENTS) {
     flags = static_cast<AllocationFlags>(DOUBLE_ALIGNMENT | flags);
   }
   __ AllocateInNewSpace(size, r0, r1, r2, fail, flags);
 
+  if (allocation_info_mode ==
+      FastCloneShallowArrayStub::TRACK_ALLOCATION_INFO) {
+    __ mov(r2, Operand(Handle<Map>(masm->isolate()->heap()->
+                                   allocation_site_info_map())));
+    __ str(r2,
+           FieldMemOperand(r0, allocation_info_start));

[danno, 2013/01/04 08:50:55]

nit: one line

[mvstanton, 2013/01/04 12:07:52]

Done.

+    __ str(r3, FieldMemOperand(r0, allocation_info_start + kPointerSize));
+  }
+
   // Copy the JS array part.
   for (int i = 0; i < JSArray::kSize; i += kPointerSize) {
     if ((i != JSArray::kElementsOffset) || (length == 0)) {
       __ ldr(r1, FieldMemOperand(r3, i));
       __ str(r1, FieldMemOperand(r0, i));
     }
   }
 
   if (length > 0) {
     // Get hold of the elements array of the boilerplate and setup the
     // elements pointer in the resulting object.
     __ ldr(r3, FieldMemOperand(r3, JSArray::kElementsOffset));
-    __ add(r2, r0, Operand(JSArray::kSize));
+    if (allocation_info_mode ==
+        FastCloneShallowArrayStub::TRACK_ALLOCATION_INFO) {
+      __ add(r2, r0, Operand(JSArray::kSize + AllocationSiteInfo::kSize));
+    } else {
+      __ add(r2, r0, Operand(JSArray::kSize));
+    }
     __ str(r2, FieldMemOperand(r0, JSArray::kElementsOffset));
 
     // Copy the elements array.
     ASSERT((elements_size % kPointerSize) == 0);
     __ CopyFields(r2, r3, r1.bit(), elements_size / kPointerSize);
   }
 }
 
 void FastCloneShallowArrayStub::Generate(MacroAssembler* masm) {
   // Stack layout on entry:
   //
   // [sp]: constant elements.
   // [sp + kPointerSize]: literal index.
   // [sp + (2 * kPointerSize)]: literals array.
 
   // Load boilerplate object into r3 and check if we need to create a
   // boilerplate.
   Label slow_case;
   __ ldr(r3, MemOperand(sp, 2 * kPointerSize));
   __ ldr(r0, MemOperand(sp, 1 * kPointerSize));
   __ add(r3, r3, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
   __ ldr(r3, MemOperand(r3, r0, LSL, kPointerSizeLog2 - kSmiTagSize));
   __ CompareRoot(r3, Heap::kUndefinedValueRootIndex);
   __ b(eq, &slow_case);
 
   FastCloneShallowArrayStub::Mode mode = mode_;
+  FastCloneShallowArrayStub::AllocationInfoMode allocation_info_mode =
+    DONT_TRACK_ALLOCATION_INFO;
+  if (mode == CLONE_ANY_ELEMENTS_WITH_ALLOCATION_INFO) {
+    mode = CLONE_ANY_ELEMENTS;
+    allocation_info_mode = TRACK_ALLOCATION_INFO;
+  }
+
   if (mode == CLONE_ANY_ELEMENTS) {
     Label double_elements, check_fast_elements;
     __ ldr(r0, FieldMemOperand(r3, JSArray::kElementsOffset));
     __ ldr(r0, FieldMemOperand(r0, HeapObject::kMapOffset));
     __ CompareRoot(r0, Heap::kFixedCOWArrayMapRootIndex);
     __ b(ne, &check_fast_elements);
     GenerateFastCloneShallowArrayCommon(masm, 0,
-                                        COPY_ON_WRITE_ELEMENTS, &slow_case);
+                                        COPY_ON_WRITE_ELEMENTS,
+                                        allocation_info_mode,
+                                        &slow_case);
     // Return and remove the on-stack parameters.
     __ add(sp, sp, Operand(3 * kPointerSize));
     __ Ret();
 
     __ bind(&check_fast_elements);
     __ CompareRoot(r0, Heap::kFixedArrayMapRootIndex);
     __ b(ne, &double_elements);
     GenerateFastCloneShallowArrayCommon(masm, length_,
-                                        CLONE_ELEMENTS, &slow_case);
+                                        CLONE_ELEMENTS,
+                                        allocation_info_mode,
+                                        &slow_case);
     // Return and remove the on-stack parameters.
     __ add(sp, sp, Operand(3 * kPointerSize));
     __ Ret();
 
     __ bind(&double_elements);
     mode = CLONE_DOUBLE_ELEMENTS;
     // Fall through to generate the code to handle double elements.
   }
 
   if (FLAG_debug_code) {
@@ skipping 11 matching lines @@
       expected_map_index = Heap::kFixedCOWArrayMapRootIndex;
     }
     __ push(r3);
     __ ldr(r3, FieldMemOperand(r3, JSArray::kElementsOffset));
     __ ldr(r3, FieldMemOperand(r3, HeapObject::kMapOffset));
     __ CompareRoot(r3, expected_map_index);
     __ Assert(eq, message);
     __ pop(r3);
   }
 
-  GenerateFastCloneShallowArrayCommon(masm, length_, mode, &slow_case);
+  GenerateFastCloneShallowArrayCommon(masm, length_, mode,
+                                      allocation_info_mode, &slow_case);
 
   // Return and remove the on-stack parameters.
   __ add(sp, sp, Operand(3 * kPointerSize));
   __ Ret();
 
   __ bind(&slow_case);
   __ TailCallRuntime(Runtime::kCreateArrayLiteralShallow, 3, 1);
 }
 
 
@@ skipping 7242 matching lines @@
 
   __ Pop(lr, r5, r1);
   __ Ret();
 }
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM