Re: Fat references vindicated

Kaz Kylheku <>
Fri, 8 Jan 2010 21:56:00 +0000 (UTC)

          From comp.compilers

Related articles
Fat references vindicated (Jon Harrop) (2010-01-08)
Re: Fat references vindicated (Kaz Kylheku) (2010-01-08)
Re: Fat references vindicated (Jon Harrop) (2010-01-10)
| List of all articles for this month |

From: Kaz Kylheku <>
Newsgroups: comp.compilers
Date: Fri, 8 Jan 2010 21:56:00 +0000 (UTC)
Organization: A noiseless patient Spider
References: 10-01-046
Keywords: storage, VM, performance
Posted-Date: 09 Jan 2010 16:14:33 EST

On 2010-01-08, Jon Harrop <> wrote:
> I just published some significant benchmark results:

I don't see fat references being vindicated.

The apparent winner of the benchmark is a C++ program running on a C++
implementation that presumably does not use fat references.

In the same blog entry above you do not argue about fat references,
but rather that HLVM comes close to C++ because, like the C++ program,
its inner loop computations are done with unboxed numbers. (Which is

Use of unboxed numeric values, and use of fat references, are orthogonal ideas.

Fat references merely make it /easy/ to implement unboxed numbers in
the face of a garbage collector that is ignorant of static type.

By using these fat references, you have built a ``four-lane highway'',
which paves the way for all your ``wide loads'' like double-precision
floats to travel anywhere that references can go. Any generic storage
location that can hold a reference also has enough space to hold an
unboxed number.

You don't think benchmarks could be written which reveal performance
disadvantages in fat references?

Post a followup to this message

Return to the comp.compilers page.
Search the comp.compilers archives again.