byte-compiler very slow

[David Ponce]

Hi All,

Since about a month, I noticed an important slow down of the
CVS version of the byte-compiler.  This is particularly annoying when
byte-compiling large files or doing batch compilation of a bunch of
files, or bootstrapping Emacs ;-)

Other people noticed that too?

To be sure I did some empiric measurements of byte-compilation time
of some files, both with Emacs 21.2.1 byte-compiler and latest CVS
one (2.105).  Here are some results I got on my IBM 390E laptop on
NT4:

 +--------------------+------------+-----------+
 | File               | 21.2.1     | 21.3.50.1 |
 +--------------------+------------+-----------+
 | bytecomp.el (1)    | 1.593S     | 18.297S   |
 | edebug.el (1)      | 1.462S     | 10.775S   |
 | wisent.java.el (2) | 5.979S     | 39.677S   |
 +--------------------+------------+-----------+
 (1) Latest CVS version
 (2) Java LALR automaton & related code (part of the Semantic
     toolkit).

A first quick comparison between the 21.2.1 and latest CVS versions of
bytecomp.el codes showed me that the main addition that could impact
performance could be related to the new (nice) feature that reports
symbol positions on byte-compiler messages.

Could it be possible to improve that code?  Or perhaps optionally
disable reporting of symbol positions, at least when running in batch
mode?

Sincerely,
David


In GNU Emacs 21.3.50.1 (i386-mingw-nt4.0.1381)
of 2002-07-20 on EBAT311
configured using `configure --with-gcc (2.95)'

Important settings:
 value of $LC_ALL: nil
 value of $LC_COLLATE: nil
 value of $LC_CTYPE: nil
 value of $LC_MESSAGES: nil
 value of $LC_MONETARY: nil
 value of $LC_NUMERIC: nil
 value of $LC_TIME: nil
 value of $LANG: ENU
 locale-coding-system: iso-latin-1
 default-enable-multibyte-characters: t