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- Subject: Re: Re: Re: NaN packing for TValue
- From: Yura Sokolov <funny.falcon@...>
- Date: Fri, 25 Feb 2011 18:43:24 +0300
-10.01.-28163 22:59, Tony Finch wrote:
On Fri, 25 Feb 2011, Peter Cawley wrote:
2011/2/24 Yura Sokolov<email@example.com>:
So that there is 3bits for tagging.
Currently Lua uses 13 different tag values, so that it would be tricky to
pack them into three bits :)
If you're willing to pay the price of an extra indirection, you might
be able to get away with using a single tag value for all GC types, as
the GC header stores the tag value.
Or steal another three bits from the bottom of the pointer...
I thought about both.
Both approaches means extra branching on extracting tag and saving it, I
Another possible solution could be utilization of fact that higher
addresses reserved for operating system's core.
So that, userland addresses are all falling in a 47 bit values.
Can anybody confirm or refute this sentence?
Sokolov Yura aka funny_falcon.