This is the mail archive of the gcc-bugs@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

[Bug optimization/13712] Executable runs 25% slower than when compiled with INTEL compiler


------- Additional Comments From uros at kss-loka dot si  2004-02-16 14:55 -------
I have done some experiments with CVS gcc-3.5 [3.5.0 20040216 (experimental)]
and gcc-3.2 [3.2 20020903 (Red Hat Linux 8.0 3.2-7)] on P4 3.2GHz, using various
options.

gcc-3.2: g++ -O3
X422 = 469.196

real    0m35.219s
user    0m35.143s
sys     0m0.061s

gcc-3.2: g++ -march=i686 -O3 -ffast-math
X422 = 469.196

real    0m29.439s
user    0m29.410s
sys     0m0.021s

gcc-3.5: g++ -march=i686 -O3 -ffast-math
X422 = 469.196

real    0m26.380s
user    0m26.287s
sys     0m0.004s

gcc-3.5: g++ -march=i686 -msse2 -mfpmath=sse -O3 -ffast-math
X422 = 469.196

real    0m26.591s
user    0m26.359s
sys     0m0.059s

gcc-3.5: g++ -march=i686 -O3 -ffast-math,
with all functions in source changed to __builtin_<function>:
HUGE_VAL => __builtin_huge_val()
sqrt() => __builtin_sqrt()
log() => __builtin_log()
exp() => __built_in_exp()
X422 = 469.196

real    0m23.145s
user    0m23.115s
sys     0m0.018s


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13712


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]