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

src/ia32/full-codegen-ia32.cc

Index: src/ia32/full-codegen-ia32.cc
diff --git a/src/ia32/full-codegen-ia32.cc b/src/ia32/full-codegen-ia32.cc
index 50713b5c141a10c9cad8a29ed77aee159f2276e1..bbe03c4a4fb6988d5986b483f6ad68b1a49ebd80 100644
--- a/src/ia32/full-codegen-ia32.cc
+++ b/src/ia32/full-codegen-ia32.cc
@@ -1678,6 +1678,14 @@ void FullCodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
     FastCloneShallowArrayStub::Mode mode = has_constant_fast_elements
         ? FastCloneShallowArrayStub::CLONE_ELEMENTS
         : FastCloneShallowArrayStub::CLONE_ANY_ELEMENTS;
+
+    // Let's track allocation info if we are SMI or DOUBLE, it might be
+    // useful to pretransition.

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

This also will track DOUBLE -> FAST_OBJECT, so the comment is a bit misleading,
right?

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

Done.

+    if (mode == FastCloneShallowArrayStub::CLONE_ANY_ELEMENTS &&
+        FLAG_use_allocation_site_info) {
+      mode = FastCloneShallowArrayStub::CLONE_ANY_ELEMENTS_WITH_ALLOCATION_INFO;
+    }
+
     FastCloneShallowArrayStub stub(mode, length);
     __ CallStub(&stub);
   }