Support Smi->Double->HeapObject transitions in constructed Arrays.

src/arm/builtins-arm.cc

Index: src/arm/builtins-arm.cc
diff --git a/src/arm/builtins-arm.cc b/src/arm/builtins-arm.cc
index d0136f550d7a12b5f0799fda7e76898dafc9e131..dc80fd749aea5e393d444550afa8385ea1991d84 100644
--- a/src/arm/builtins-arm.cc
+++ b/src/arm/builtins-arm.cc
@@ -394,13 +394,19 @@ static void ArrayNativeCode(MacroAssembler* masm,
   // r5: elements_array_end (untagged)
   // sp[0]: last argument
   Label loop, entry;
+  Label bailout;

[Jakob Kummerow, 2011/12/07 17:02:47]

Unused label. (Does this even compile with -Werror?)

[danno, 2011/12/08 15:09:09]

Done.

+  __ mov(r7, sp);

[Jakob Kummerow, 2011/12/07 17:02:47]

Why? I don't see how sp would get overwritten.

[danno, 2011/12/08 15:09:09]

I didn't see it initially, either, and it cost me about an hour. MemOperand(r7,
kPointerSize, PostIndex) below changes r7. 
On 2011/12/07 17:02:47, Jakob wrote:

   __ jmp(&entry);
   __ bind(&loop);
-  __ ldr(r2, MemOperand(sp, kPointerSize, PostIndex));
+  __ ldr(r2, MemOperand(r7, kPointerSize, PostIndex));
+  if (FLAG_smi_only_arrays) {
+    __ JumpIfNotSmi(r2, call_generic_code);
+  }
   __ str(r2, MemOperand(r5, -kPointerSize, PreIndex));
   __ bind(&entry);
   __ cmp(r4, r5);
   __ b(lt, &loop);
+  __ mov(sp, r7);
 
   // Remove caller arguments and receiver from the stack, setup return value and
   // return.