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

src/ia32/code-stubs-ia32.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 293 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,
+    bool want_allocation_info,

[danno, 2012/12/26 10:32:01]

Instead of passing a bool, create a enum in the header (we do this elsewhere)
called something like AllocationInfoMode with TRACK_ALLOCATION_INFO and
DONT_TRACK_ALLOCATION_INFO. This makes it clearer what's going on at a caller's
invocation site. Perhaps just supporting the mode_ without converting to a
separate bool might make the code closer.

[mvstanton, 2013/01/03 14:40:43]

Done...I made a separate enum. I'd like to coalesce the two fields which seems
like the right thing to do. But what happens is that one parent function will
make multiple calls to this function with different
FastCloneShallowArrayStub::Modes, building one general stub from several
specific cases. It seemed better to separate the allocationinfomode concern from
the elements/double concern.

     Label* fail) {
   // Registers on entry:
   //
   // ecx: 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 (want_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.
   __ AllocateInNewSpace(size, eax, ebx, edx, fail, TAG_OBJECT);
 
+  if (want_allocation_info) {
+    __ mov(FieldOperand(eax, allocation_info_start),
+           Immediate(Handle<Map>(masm->isolate()->heap()->
+                                 allocation_site_info_map())));
+    __ mov(FieldOperand(eax, allocation_info_start + kPointerSize), ecx);
+           // type_info_cell);

[danno, 2012/12/26 10:32:01]

nit: delete comment

[mvstanton, 2013/01/03 14:40:43]

Done.

+  }
+
   // Copy the JS array part.
   for (int i = 0; i < JSArray::kSize; i += kPointerSize) {
     if ((i != JSArray::kElementsOffset) || (length == 0)) {
       __ mov(ebx, FieldOperand(ecx, i));
       __ mov(FieldOperand(eax, i), ebx);
     }
   }
 
   if (length > 0) {
     // Get hold of the elements array of the boilerplate and setup the
     // elements pointer in the resulting object.
     __ mov(ecx, FieldOperand(ecx, JSArray::kElementsOffset));
-    __ lea(edx, Operand(eax, JSArray::kSize));
+    if (want_allocation_info) {
+      __ lea(edx, Operand(eax, JSArray::kSize + AllocationSiteInfo::kSize));
+    } else {
+      __ lea(edx, Operand(eax, JSArray::kSize));
+    }
     __ mov(FieldOperand(eax, JSArray::kElementsOffset), edx);
 
     // Copy the elements array.
     if (mode == FastCloneShallowArrayStub::CLONE_ELEMENTS) {
       for (int i = 0; i < elements_size; i += kPointerSize) {
         __ mov(ebx, FieldOperand(ecx, i));
         __ mov(FieldOperand(edx, i), ebx);
       }
     } else {
       ASSERT(mode == FastCloneShallowArrayStub::CLONE_DOUBLE_ELEMENTS);
@@ skipping 29 matching lines @@
   STATIC_ASSERT(kSmiTag == 0);
   __ mov(ecx, FieldOperand(ecx, eax, times_half_pointer_size,
                            FixedArray::kHeaderSize));
   Factory* factory = masm->isolate()->factory();
   __ cmp(ecx, factory->undefined_value());
   Label slow_case;
   __ j(equal, &slow_case);
 
   FastCloneShallowArrayStub::Mode mode = mode_;
   // ecx is boilerplate object.
+  bool want_allocation_info = false;
+  if (mode == CLONE_ANY_ELEMENTS_WITH_ALLOCATION_INFO) {
+    mode = CLONE_ANY_ELEMENTS;
+    want_allocation_info = true;
+  }
+
   if (mode == CLONE_ANY_ELEMENTS) {
     Label double_elements, check_fast_elements;
     __ mov(ebx, FieldOperand(ecx, JSArray::kElementsOffset));
     __ CheckMap(ebx, factory->fixed_cow_array_map(),
                 &check_fast_elements, DONT_DO_SMI_CHECK);
     GenerateFastCloneShallowArrayCommon(masm, 0,
-                                        COPY_ON_WRITE_ELEMENTS, &slow_case);
+                                        COPY_ON_WRITE_ELEMENTS,
+                                        want_allocation_info,
+                                        &slow_case);
     __ ret(3 * kPointerSize);
 
     __ bind(&check_fast_elements);
     __ CheckMap(ebx, factory->fixed_array_map(),
                 &double_elements, DONT_DO_SMI_CHECK);
     GenerateFastCloneShallowArrayCommon(masm, length_,
-                                        CLONE_ELEMENTS, &slow_case);
+                                        CLONE_ELEMENTS,
+                                        want_allocation_info,
+                                        &slow_case);
     __ ret(3 * kPointerSize);
 
     __ bind(&double_elements);
     mode = CLONE_DOUBLE_ELEMENTS;
     // Fall through to generate the code to handle double elements.
   }
 
   if (FLAG_debug_code) {
     const char* message;
     Handle<Map> expected_map;
     if (mode == CLONE_ELEMENTS) {
       message = "Expected (writable) fixed array";
       expected_map = factory->fixed_array_map();
     } else if (mode == CLONE_DOUBLE_ELEMENTS) {
       message = "Expected (writable) fixed double array";
       expected_map = factory->fixed_double_array_map();
     } else {
       ASSERT(mode == COPY_ON_WRITE_ELEMENTS);
       message = "Expected copy-on-write fixed array";
       expected_map = factory->fixed_cow_array_map();
     }
     __ push(ecx);
     __ mov(ecx, FieldOperand(ecx, JSArray::kElementsOffset));
     __ cmp(FieldOperand(ecx, HeapObject::kMapOffset), expected_map);
     __ Assert(equal, message);
     __ pop(ecx);
   }
 
-  GenerateFastCloneShallowArrayCommon(masm, length_, mode, &slow_case);
+  GenerateFastCloneShallowArrayCommon(masm, length_, mode,
+                                      want_allocation_info, &slow_case);
   // Return and remove the on-stack parameters.
   __ ret(3 * kPointerSize);
 
   __ bind(&slow_case);
   __ TailCallRuntime(Runtime::kCreateArrayLiteralShallow, 3, 1);
 }
 
 
 void FastCloneShallowObjectStub::Generate(MacroAssembler* masm) {
   // Stack layout on entry:
@@ skipping 7001 matching lines @@
   // Restore ecx.
   __ pop(ecx);
   __ ret(0);
 }
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32