How to identify 32 or 64 bits -

Bryn M. Reeves bmr at redhat.com
Thu Dec 17 13:56:23 UTC 2009


On Thu, 2009-12-17 at 13:48 +0000, Patrick O'Callaghan wrote:
> bash-4.0$ grep lm /proc/cpuinfo
> flags           : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx constant_tsc arch_perfmon pebs bts pni dtes64 monitor ds_cpl est tm2 ssse3 xtpr pdcm movbe lahf_lm
> flags           : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx constant_tsc arch_perfmon pebs bts pni dtes64 monitor ds_cpl est tm2 ssse3 xtpr pdcm movbe lahf_lm
> bash-4.0$
> 
> (the lahf_lm flag matches, though I've no idea what it means).

arch/x86/include/asm/cpufeature.h says it indicates whether the
LAHF/SAHF (load status flags to AH /save AH to status flags)
instructions are available in long mode.

I'm not sure what it implies if you have lahf_lm but not lm!

Regards,
Bryn.





More information about the fedora-list mailing list