Duraid,
How about collecting some profiles (e.g., with qprof or q-syscollect)?
That might be a quick way to get some idea as to what's causing the
regression.
--david
>>>>> On Sun, 3 Apr 2005 16:04:48 +0200, Matthias Klose <[EMAIL PROTECTED]>
>>>>> said:
Matthias> according to the changelog, nothing really has changed
Matthias> ... CCing to the ia64 list.
Matthias> Duraid Madina writes:
>> Hi Mathias, Gerhard and others,
>>
>> I want to report a nasty performance regression in
>> 3.3.5-12. Moving from:
>>
>> gcc version 3.3.5 (Debian 1:3.3.5-11)
>>
>> to:
>>
>> gcc version 3.3.5 (Debian 1:3.3.5-12)
>>
>> leads to a large reduction in C++ software build speeds, due to
>> something that apparently makes 'ld' spend much, much more time
>> than it previously did. I reproduced this problem going backwards
>> and forwards between these versions by commands like:
>>
>> dpkg -i g++-3.3_3.3.5-11_ia64.deb gcc-3.3-base_3.3.5-11_ia64.deb
>> gcc-3.3_3.3.5-11_ia64.deb
>>
>> so, as far as I understand, neither libstdc++ nor binutils
>> changed.
>>
>> How bad is the problem? Trying to build the LLVM compiler suite,
>> (say, version 1.4 from http://llvm.cs.uiuc.edu/releases/ ) on a
>> 2-way IA64 system with a simple ./configure; time make -j2 with
>> gcc 3.3.5-11 gives:
>>
>> real 1048.03 user 1979.93 sys 54.37
>>
>> but with gcc 3.3.5-12 gives:
>>
>> real 1641.14 user 3037.64 sys 49.62
>>
>> Nasty! The build takes 60% longer with 3.3.5-12, and while I
>> haven't timed it accurately, the time spent in linking has
>> _greatly_ increased, by a factor of at least 5x, perhaps
>> 10x. LLVM is fairly "normal" and portable C++, though it is a
>> large source base. (not quite mozilla-sized, though)
>>
>> Unfortunately, build times from (gcc version 3.4.4 20050314
>> (prerelease) (Debian 3.4.3-12)) are more or less the same as
>> those of 3.3.5-12, i.e. slow. Again, components of LLVM take
>> literally minutes to link on a rather snappy Itanium system. I
>> have not tested older versions of 3.4 to see if these too have
>> the performance regression from 3.3.5-11.
>>
>> I would appreciate it if you could bring this to the attention of
>> the relevant people, and I hope I'm posting this in the right
>> place! If anyone wants an even more painless way of reproducing
>> this problem, please contact me and I will provide a tarball that
>> you can simply unpack, configure, make. I'd also appreciate it if
>> someone could confirm exactly what has changed between the
>> 3.3.5-11 and 3.3.5-12 packages of gcc, gcc-base and g++. diffing
>> gcc-3.3_3.3.5-11.diff and gcc-3.3_3.3.5-12.diff, I can't see
>> anything obviously responsible for this regression, so I wonder
>> if perhaps some sort of changed environment on whatever machine
>> built gcc-3.3.5-12 might be responsible for this regression.
>>
>> Finally, note that this is all on ia64. I imagine it is likely
>> that this regression is platform specific, but the only Debian
>> systems I have ready access to are ia64 ones, so I can't test
>> this.
>>
>> Many thanks in advance,
>>
>> Duraid
>>
>>
>> --
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