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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


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