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[Bug c++/14809] performance depends on allocation methods
- From: "aleks at physik dot tu-berlin dot de" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 3 May 2004 17:26:21 -0000
- Subject: [Bug c++/14809] performance depends on allocation methods
- References: <20040401120607.14809.boeck@fhi-berlin.mpg.de>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Additional Comments From aleks at physik dot tu-berlin dot de 2004-05-03 17:26 -------
REOPEN the bug 14809: i can verify the problem partly.
performance with global static arrays of double's is up to 10% higher as with
pointers to dynamic (new or malloc) arrays of same size and type!!
PSA .. pointer to static arrays
time(average over 5runs): (big matrix multiplications, g++)
static=21.8sec; PSA=23.4sec ;dyn.new=23.4sec; dyn.malloc=23.0sec
(last week i had up to 3 sec diff.!?)
result: pointers slow down my prog!?
used memory: ca. 05 megabyte
computer: kernel 2.4.23-1.SMP i686
Dual Processor Pentium III, 1.2 GHz, 512K L2-Cache, 2530 bogomips
Red Hat Linux(2years old, but some updates (gcc,kernel,libs)
GCC: -3.3.3 --enable-shared --enable-languages=c,c++,f77
Thread model: posix, gcc version 3.3.3
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14809