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Re: Convergence of GCC - slightly off topic
- From: Matt Austern <austern at apple dot com>
- To: Joe Buck <Joe dot Buck at synopsys dot com>
- Cc: yabadabadoo123 at hotmail dot com, gcc at gcc dot gnu dot org
- Date: Thu, 3 Oct 2002 13:48:57 -0700
- Subject: Re: Convergence of GCC - slightly off topic
On Thursday, October 3, 2002, at 11:40 AM, Joe Buck wrote:
Because of the more complete standard C++ headers and because
performance
tuning isn't complete, 3.2.x (the compiler itself) runs more slowly
than
2.95. The effect is most noticeable for small programs that include
standard headers like <iostream>: you may have just written "Hello,
world"
but the compiler has to process tens of thousands of lines of headers.
An addendum: there's active work on the compile time issue;
lots of people care about it, but Apple is especially interested.
One line of attack is making sure that if you have a project with
a hundred files in it then the tens of thousands of lines of code
get processed once when compiling the project, not once for
each file. Another line of attack is making sure that the time
spent on compiling a source file is proportional to the code that
the user wrote, not proportional to the code in the header. And
then, as Joe pointed out, there's also ordinary performance
tuning.
We can reasonably expect that future versions of g++ will be much
faster than 3.2 is.
--Matt