core2 popcnt

[frankp]

Does the core2 (Yorkfield 45nm) have hardware popcount, or is it only the i7 Nahalem - and later cores?

[Nick C]

Does the core2 (Yorkfield 45nm) have hardware popcount, or is it only the i7 Nahalem - and later cores?

The latter, unfortunately my QX9650 (Yorkfield 45nm) does not have POPCNT. The AMD 10h processor range has POPCNT also.

[trojanfoe]

During runtime you can test CPU capabilities using the 'cpuid' instruction:

Code: Select all

get_cpu_caps PROC
	mov eax, 01h
	cpuid					; ecx=feature info 1, edx=feature info 2

	xor eax, eax			; prepare return value

	test edx, 1 SHL 0
	jz not_fpu
	or eax, CPUCAP_FPU

not_fpu:
	test edx, 1 SHL 23

... blah blah blah ....

	test ecx, 1 SHL 23
	jz not_popcnt
	or eax, CPUCAP_POPCNT

not_popcnt:
	ret

get_cpu_caps ENDP