Implement tracking and optimizations of packed arrays

src/ia32/ic-ia32.cc

Index: src/ia32/ic-ia32.cc
diff --git a/src/ia32/ic-ia32.cc b/src/ia32/ic-ia32.cc
index dc64a09d839088ec8e3633bf5124f14f5a67b460..0135f21934606a1d3072c8884209ebcc73f4fa7c 100644
--- a/src/ia32/ic-ia32.cc
+++ b/src/ia32/ic-ia32.cc
@@ -889,9 +889,9 @@ void KeyedStoreIC::GenerateGeneric(MacroAssembler* masm,
               &non_double_value,
               DONT_DO_SMI_CHECK);
 
-  // Value is a double. Transition FAST_SMI_ONLY_ELEMENTS ->
-  // FAST_DOUBLE_ELEMENTS and complete the store.
-  __ LoadTransitionedArrayMapConditional(FAST_SMI_ONLY_ELEMENTS,
+  // Value is a double. Transition FAST_*_SMI_ELEMENTS -> FAST_*_DOUBLE_ELEMENTS

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

The comment says that FAST_*_SMI_ELEMENTS are transitioned, but
FAST_HOLEY_SMI_ELEMENTS actually jump to &slow. Is that intentional?

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

For now, yes. When Toon finishes his changes, all cases will be handled here. 
On 2012/05/13 21:55:27, Jakob wrote:

+  // and complete the store.
+  __ LoadTransitionedArrayMapConditional(FAST_SMI_ELEMENTS,
                                          FAST_DOUBLE_ELEMENTS,
                                          ebx,
                                          edi,
@@ -902,12 +902,12 @@ void KeyedStoreIC::GenerateGeneric(MacroAssembler* masm,
 
   __ bind(&non_double_value);
   // Value is not a double, FAST_SMI_ONLY_ELEMENTS -> FAST_ELEMENTS

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

nit: s/ONLY_// or s/ONLY_/*_/.
Also, HOLEY elements again aren't handled in the fast path. Intentional?

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

Done.

-  __ LoadTransitionedArrayMapConditional(FAST_SMI_ONLY_ELEMENTS,
+  __ LoadTransitionedArrayMapConditional(FAST_SMI_ELEMENTS,
                                          FAST_ELEMENTS,
                                          ebx,
                                          edi,
                                          &slow);
-  ElementsTransitionGenerator::GenerateSmiOnlyToObject(masm);
+  ElementsTransitionGenerator::GenerateMapChangeElementTransition(masm);
   __ mov(ebx, FieldOperand(edx, JSObject::kElementsOffset));
   __ jmp(&finish_object_store);