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Re: What's the spec for emacs lisp virtual machine ?
From: |
Fren Zeee |
Subject: |
Re: What's the spec for emacs lisp virtual machine ? |
Date: |
Wed, 08 Dec 2010 15:21:59 -0000 |
User-agent: |
G2/1.0 |
On Jul 29, 8:51 pm, mdj <mdj....@gmail.com> wrote:
> On Jul 23, 4:12 pm, Fren Zeee <frenz...@gmail.com> wrote:
>
> > Why is a VM needed when there is compiled C code running machine
> > code ?
>
> The are two essential reasons. Firstly, the bytecode is more compact
> in memory than either the machine code or the READ lisp code.
> Secondly, it loads a good deal faster from disk, allowing emacs to
> start (relatively) quickly.
an example
preferably from an emacs file from savannah link so one could get an
idea of the animal.
theoretical reasons for speed ?
> Thirdly, it is relatively straightforward to implement a portable
> bytecode interpreter in C that will then compile on any architecture
> for which one has a C compiler. This is a great deal less work than
> developing a 'to-machine-code' compiler for every architecture out
> there.
Why is it less than porting the C compiler ? How would it be written ?
assembler ?
> Keep in mind that the early releases of GNU Emacs were in the mid
> 1980's when personal computers powerful enough to run Emacs had
> typically perhaps 1mb of RAM. Keeping the in-memory footprint of Emacs
> small was more important than raw speed which would need more RAM, and
> necessitate customizer the code generator for every conceivable
> architecture.
> In 1989 there were a LOT of 32bit microprocessor architectures out
> there, and many still survive to this day.
> To answer the rest of your questions, I'd recommend enrolling in a
> good computer science degree.
I am sure someone can point to a tutorial paper or book,
no one need you to give that obvious advice ... so obvious that i
consider rude
> Matt
- What's the spec for emacs lisp virtual machine ?, Fren Zeee, 2010/12/08
- Re: What's the spec for emacs lisp virtual machine ?, Pascal J. Bourguignon, 2010/12/08
- Re: What's the spec for emacs lisp virtual machine ?, Fren Zeee, 2010/12/08
- Re: What's the spec for emacs lisp virtual machine ?, Fren Zeee, 2010/12/08
- Re: What's the spec for emacs lisp virtual machine ?, Fren Zeee, 2010/12/08
- Re: What's the spec for emacs lisp virtual machine ?, Pascal J. Bourguignon, 2010/12/08
- Re: What's the spec for emacs lisp virtual machine ?, Barry Margolin, 2010/12/08
- Re: What's the spec for emacs lisp virtual machine ?, Emmy Noether, 2010/12/09
- Re: What's the spec for emacs lisp virtual machine ?, Pascal J. Bourguignon, 2010/12/08
Re: What's the spec for emacs lisp virtual machine ?, mdj, 2010/12/08