NetNews Usenet Archive 1993 #3/NN_1993_3.iso/spool/comp/lang/modula3/1168

Text File | 1993-01-28 | 1.8 KB | 43 lines

Newsgroups: comp.lang.modula3
Path: sparky!uunet!charon.amdahl.com!pacbell.com!decwrl!src.dec.com!src.dec.com!mjordan
From: [e-mail] (Mick Jordan)
Subject: Re: Why are M3 executables so big?
Message-ID: <[e-mail]>
Sender: [e-mail] (News)
Organization: DEC Systems Research Center
References:  <[e-mail]>
Distribution: usa
Date: Wed, 27 Jan 93 03:07:07 GMT
Lines: 30

In article <[e-mail]>, [e-mail] (David Sims) writes:
|> Why does the following hello-world program create a 400K stripped
|> executable on my Sparc box?  The .mo file is a mere 399 bytes, but the
|> executable balloons to 400K.  Are the Wr, Stdio, and other run-time
|> libraries really that large?
|>

This is an old chestnut that many new users find astonishing, but we ought to
put it in a little perspective. First, all programs include a relatively
sophisticated storage manager and garbage collector, a lightweight process
package (Thread), and a run-time type system. These artefacts, that in other
languages would count as user libraries, cost quite a bit in code and data
size. There is also some overhead that arises from generating C code instead
of native machine code.

In addition, there is substantially more functionality in the libraries,
than hello-world actually needs. We have not tried very hard to structure
the library into small components. I have a prototype tool that optimises
whole M3 programs and, when applied to hello-world, generates an
executable that is 220K in size, as opposed to 417K, on a DECstation 5000.
If this is then optimised with the C compiler, it reduces to 177K.

Of course, since you are running on a Sparc, you can use shared libraries
to mitigate the size of executables.

Mick Jordan