GMP 4.3.1 misdetects intel X7460

[David Harvey]

Hi,

GMP 4.3.1 is misdetecting the following chip (intel xeon X7460  
dunnington):

processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 29
model name      : Intel(R) Xeon(R) CPU           X7460  @ 2.66GHz
stepping        : 1
cpu MHz         : 2666.761
cache size      : 16384 KB
physical id     : 0
siblings        : 6
core id         : 0
cpu cores       : 6
fpu             : yes
fpu_exception   : yes
cpuid level     : 11
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr  
pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm  
pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good pni  
monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr dca sse4_1 lahf_lm
bogomips        : 5336.60
clflush size    : 64
cache_alignment : 64
address sizes   : 40 bits physical, 48 bits virtual
power management:

I get

checking build system type... atom-unknown-linux-gnu
checking host system type... atom-unknown-linux-gnu
[...]
using ABI="64"
       CC="gcc"
       CFLAGS="-O2 -pedantic -m64 -m486"
       CPPFLAGS=""
       MPN_PATH=" x86_64/atom x86_64 generic"

and consequently

$ ./speed -C -s 1000 mpn_mul_n
overhead 6.12 cycles, precision 10000 units of 3.75e-10 secs, CPU  
freq 2666.76 MHz
             mpn_mul_n
1000        1061.9900

whereas if I build with "./configure --build=core2-unknown-linux- 
gnu" (which is what GMP 4.2.4 does), I get

             mpn_mul_n
1000         780.3300

I also tried with the current GMP repo and the same thing happens.

david