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[Bug rtl-optimization/13712] Executable runs 25% slower than when compiled with INTEL compiler
- From: "uros at kss-loka dot si" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 24 Jan 2005 11:16:07 -0000
- Subject: [Bug rtl-optimization/13712] Executable runs 25% slower than when compiled with INTEL compiler
- References: <20040116211131.13712.william.crocker@analog.com>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Additional Comments From uros at kss-loka dot si 2005-01-24 11:16 -------
(In reply to comment #14)
> Where are we standing with this one today?
gcc version 4.0.0 20050124 (experimental)
g++ -O3 -ffast-math y.cc
real 0m27.102s
user 0m26.980s
sys 0m0.016s
g++ -O3 -ffast-math -D__NO_MATH_INLINES y.cc
real 0m23.484s
user 0m23.307s
sys 0m0.076s
g++ -O3 -march=pentium4 -ffast-math -D__NO_MATH_INLINES y.cc
real 0m23.101s
user 0m23.014s
sys 0m0.078s
g++ -O3 -march=pentium4 -mfpmath=sse -ffast-math -D__NO_MATH_INLINES y.cc
real 0m31.650s
user 0m31.605s
sys 0m0.025s
g++ -O3 -march=pentium4 -mfpmath=sse -ffast-math y.cc
real 0m29.068s
user 0m28.863s
sys 0m0.023s
g++ -O3 -march=pentium4 -mfpmath=sse y.cc
real 0m35.343s
user 0m34.848s
sys 0m0.047s
g++ -O3 -march=pentium4 -mfpmath=sse -ffast-math -mno-80387 -D__NO_MATH_INLINES y.cc
*** FAILED: X422 = nan ***
real 2m56.700s
user 2m55.615s
sys 0m0.145s
g++ -O3 -march=pentium4 -mfpmath=sse -mno-80387 -D__NO_MATH_INLINES y.cc
*** TIMEOUT AFTER 3min ***
-mfpmath=sse runs a bit slow.
-mno-80387 IMHO generates wrong code.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13712