Implement tracking and optimizations of packed arrays

src/ia32/stub-cache-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 1448 matching lines @@
       if (FLAG_smi_only_arrays  && !FLAG_trace_elements_transitions) {
         Label fast_object, not_fast_object;
         __ CheckFastObjectElements(ebx, &not_fast_object, Label::kNear);
         __ jmp(&fast_object);
         // In case of fast smi-only, convert to fast object, otherwise bail out.
         __ bind(&not_fast_object);
         __ CheckFastSmiOnlyElements(ebx, &call_builtin);
         // edi: elements array
         // edx: receiver
         // ebx: map
-        __ LoadTransitionedArrayMapConditional(FAST_SMI_ONLY_ELEMENTS,
+        Label try_holey_map;
+        __ LoadTransitionedArrayMapConditional(FAST_HOLEY_SMI_ELEMENTS,

[Jakob Kummerow, 2012/05/13 21:55:27]

Didn't you mean to check for packed FAST_SMI_ELEMENTS here, and then for
FAST_HOLEY_SMI_ELEMENTS after "__ bind(&try_holey_map)"? I guess it doesn't
really make a difference, but the current naming is confusing.

[danno, 2012/05/22 11:05:21]

Done.

+                                               FAST_HOLEY_ELEMENTS,
+                                               ebx,
+                                               edi,
+                                               &try_holey_map);
+
+        ElementsTransitionGenerator::
+            GenerateMapChangeElementTransition(masm());
+        // Restore edi.
+        __ mov(edi, FieldOperand(edx, JSArray::kElementsOffset));
+        __ jmp(&fast_object);
+
+        __ bind(&try_holey_map);
+        __ LoadTransitionedArrayMapConditional(FAST_SMI_ELEMENTS,
                                                FAST_ELEMENTS,
                                                ebx,
                                                edi,
                                                &call_builtin);
-        ElementsTransitionGenerator::GenerateSmiOnlyToObject(masm());
+        ElementsTransitionGenerator::
+            GenerateMapChangeElementTransition(masm());
         // Restore edi.
         __ mov(edi, FieldOperand(edx, JSArray::kElementsOffset));
         __ bind(&fast_object);
       } else {
         __ CheckFastObjectElements(ebx, &call_builtin);
       }
 
       // Save new length.
       __ mov(FieldOperand(edx, JSArray::kLengthOffset), eax);
 
@@ skipping 2326 matching lines @@
   // -----------------------------------
   Label miss_force_generic, grow, slow, transition_elements_kind;
   Label check_capacity, prepare_slow, finish_store, commit_backing_store;
 
   // This stub is meant to be tail-jumped to, the receiver must already
   // have been verified by the caller to not be a smi.
 
   // Check that the key is a smi or a heap number convertible to a smi.
   GenerateSmiKeyCheck(masm, ecx, ebx, xmm0, xmm1, &miss_force_generic);
 
-  if (elements_kind == FAST_SMI_ONLY_ELEMENTS) {
+  if (IsFastSmiElementsKind(elements_kind)) {
     __ JumpIfNotSmi(eax, &transition_elements_kind);
   }
 
   // Get the elements array and make sure it is a fast element array, not 'cow'.
   __ mov(edi, FieldOperand(edx, JSObject::kElementsOffset));
   if (is_js_array) {
     // Check that the key is within bounds.
     __ cmp(ecx, FieldOperand(edx, JSArray::kLengthOffset));  // smis.
     if (grow_mode == ALLOW_JSARRAY_GROWTH) {
       __ j(above_equal, &grow);
     } else {
       __ j(above_equal, &miss_force_generic);
     }
   } else {
     // Check that the key is within bounds.
     __ cmp(ecx, FieldOperand(edi, FixedArray::kLengthOffset));  // smis.
     __ j(above_equal, &miss_force_generic);
   }
 
   __ cmp(FieldOperand(edi, HeapObject::kMapOffset),
          Immediate(masm->isolate()->factory()->fixed_array_map()));
   __ j(not_equal, &miss_force_generic);
 
   __ bind(&finish_store);
-  if (elements_kind == FAST_SMI_ONLY_ELEMENTS) {
+  if (IsFastSmiElementsKind(elements_kind)) {
     // ecx is a smi, use times_half_pointer_size instead of
     // times_pointer_size
     __ mov(FieldOperand(edi,
                         ecx,
                         times_half_pointer_size,
                         FixedArray::kHeaderSize), eax);
   } else {
-    ASSERT(elements_kind == FAST_ELEMENTS);
+    ASSERT(IsFastObjectElementsKind(elements_kind));
     // Do the store and update the write barrier.
     // ecx is a smi, use times_half_pointer_size instead of
     // times_pointer_size
     __ lea(ecx, FieldOperand(edi,
                              ecx,
                              times_half_pointer_size,
                              FixedArray::kHeaderSize));
     __ mov(Operand(ecx, 0), eax);
     // Make sure to preserve the value in register eax.
     __ mov(ebx, eax);
@@ skipping 216 matching lines @@
     __ jmp(ic_slow, RelocInfo::CODE_TARGET);
   }
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32