v8 big array performance bugs

1.js

for (var a = [], i = 0; i < 64*1024*1024; ++i) a.push(123.456);

2.js

for (var a = [123.456], i = 0; i < 64*1024*1024; ++i) a.push(123.456);

log

$ time out/native/d8 tmp/big-array/1.js 
real    0m3.672s
user    0m3.176s
sys     0m0.452s

$ time out/native/d8 tmp/big-array/2.js 
#
# Fatal error in CALL_AND_RETRY_0
# Allocation failed - process out of memory
#

Trace/breakpoint trap (core dumped)

real    0m52.356s
user    0m51.995s
sys     0m0.416s

http://code.google.com/p/v8/issues/detail?id=2392