"Stroller" 写入消息
news:0bead785-392b-49e3-a3d1-0f015b954...@stellar.eclipse.co.uk...
Hi there,
I have a Sun / Cobalt Qube 3 with an AMD K6-2+ CPU, and gcc seems to be
misdetecting it as an Athlon when using -march=native
# gcc -v -Q --help=target -march=native 2>&1 | grep march
/usr/libexec/gcc/i586-pc-linux-gnu/4.5.2/cc1 -v
help-dummy -D_FORTIFY_SOURCE=2 -march=athlon --param
l1-cache-size=32 --param l1-cache-line-size=32 --param
l2-cache-size=128 -mtune=athlon -dumpbase help-dummy -auxbase
help-dummy -version -fhelp=target -o /tmp/ccQrke9q.s
-march= athlon
#
I've tried a couple of different versions of gcc - 4.4.4 and 4.5.2 - but
they both show the same.
Someone on the linux-cobalt mailing list can also reproduce.
When I compile nano using `-march=i586`, `-march=k6-2` or `-march=k6-3` it
works fine.
If I compile it with `-march=native` then nano crashes on startup saying
"illegal instruction".
/proc/cpuinfo seems to show the CPU correctly:
# cat /proc/cpuinfo
processor : 0
vendor_id : AuthenticAMD
cpu family : 5
model : 13
model name : AMD-K6(tm)-III Processor
stepping : 4
cpu MHz : 448.140
cache size : 128 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 cx8 pge mmx syscall 3dnowext
3dnow k6_mtrr
bogomips : 896.28
clflush size : 32
cache_alignment : 32
address sizes : 32 bits physical, 32 bits virtual
power management: ts fid vid
#
AIUI the K6-2+ is architecturally the same as a K6-3, so I assume this is
fine. The family & model above match what wikipedia says it should be for
a K6-2+ (although they're also the same for a K6-3+).
It's a bug in GCC. Can you try the patch at
http://gcc.gnu.org/bugzilla/attachment.cgi?id=24233?
--
Zuxy
