GCC Compile-Time Regressions

[Matt Austern]

On Thursday, February 13, 2003, at 12:57 PM, Neil Booth wrote:

> Ziemowit Laski wrote:-
>
>> Just for completeness, I thought I'd share my measurements for release
>> branches other than 3.3.x.
>>
>> Currently, there is some controversy as to whether 3.4/TOT is actually
>> slower than 3.3.  My measurements
>> consistently confirm this thesis, although some folks apparently found
>> the reverse to be true.  A suggestion
>> has been made (on this list, I believe) that 3.4 may be slower on 
>> small
>> files but faster on big ones.  So,
>> is my test case considered small or large? The structparser.cpp file
>> itself is indeed very small, but it
>> pulls in a lot of Qt and STL gunk via #include and balloons up to 1 
>> Mb,
>> which I would no longer consider
>> small.  So, if someone (other than me) could do some systematic
>> 3.3-vs-3.4 measurements and post the results
>> here, that would be great.
>
> How come the .ii file is so different?  /me guesses tabs have become
> spaces.

The C++ library was completely rewritten between 2.95 and 3.x.  The
3.x library has localization support, templatized streams, etc.  No
surprise at all that a C++ .ii file is much larger in 3.x.

			--Matt