------- Additional Comments From vda at port dot imtp dot ilyichevsk dot odessa
dot ua 2005-04-27 05:38 -------
Marking as invalid. I found out that this happens on Celeron
but doesn't happen on Athlon. Must be instruction scheduling
artifact.
Same binaries were used:
# gcc -O2 -o twofish_O2 twofish.c
# gcc -O3 -o twofish_O3 twofish.c
# gcc -Os -o twofish_Os twofish.c
# gcc -o twofish twofish.c
On Celeron:
# ./twofish
Iterations/sec: 63584
# ./twofish_O2
Iterations/sec: 41836
# ./twofish_O3
Iterations/sec: 42604
# ./twofish_Os
Iterations/sec: 45956
# gcc -v
gcc version 3.4.3
# cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 11
model name : Intel(R) Celeron(TM) CPU
stepping : 1
cpu MHz : 1196.222
cache size : 256 KB
physical id : 0
siblings : 1
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 2
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov
pat pse36 mmx fxsr sse
bogomips : 2359.29
On Athlon:
# ./twofish
Iterations/sec: 65648
# ./twofish_O2
Iterations/sec: 64484
# ./twofish_O3
Iterations/sec: 71596
# ./twofish_Os
Iterations/sec: 63560
# cat /proc/cpuinfo
processor : 0
vendor_id : AuthenticAMD
cpu family : 6
model : 8
model name : AMD Athlon(tm) XP 2400+
stepping : 1
cpu MHz : 2009.954
cache size : 256 KB
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 1
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov
pat pse36
mmx fxsr sse pni syscall mmxext 3dnowext 3dnow
bogomips : 3964.92
--
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution| |INVALID
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21147
