This is the mail archive of the
gcc-bugs@gcc.gnu.org
mailing list for the GCC project.
[Bug tree-optimization/17050] [4.0 Regression] Performance pessimisation as compared to GCC 3.4
- From: "dberlin at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 26 Nov 2004 22:33:14 -0000
- Subject: [Bug tree-optimization/17050] [4.0 Regression] Performance pessimisation as compared to GCC 3.4
- References: <20040816152907.17050.coyote@coyotegulch.com>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Additional Comments From dberlin at gcc dot gnu dot org 2004-11-26 22:33 -------
On my pentium-m, 3.4 gets:
dberlin@linux:~> gcc -O3 -std=c99 coyotebench_mole.i -ffast-math -lrt -lm
dberlin@linux:~> time ./a.out
run time: 23.438668
real 0m24.187s
user 0m23.147s
sys 0m0.368s
and the tree-cleanup-branch gets
dberlin@linux:~/gcc-tcb/build/gcc> ./xgcc -B./ -std=c99 -O3 -ffast-math
~/coyotebench_mole.i -lrt -lm
timdberlin@linux:~/gcc-tcb/build/gcc> time ./a.out
run time: 8.626844
real 0m8.919s
user 0m8.803s
sys 0m0.039s
I haven't redone mainline yet.
But it's good to know that TCB has this problem fixed, which means it will
likely be gone in 4.1 if not sooner.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17050