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I have been working on a way to convert a hex string to a dword, I have come up with this. It currently takes around 104 clocks to convert "0xffffffff" but I am sure it can be faster. Anyone have any optimization ideas ?

It has to handle trailing H or h and leading 0 or 0x. In my version if cbLen is 0 it will calculate the length but that is not necessary if it can be done faster...

hex2dw FRAME pString,cbLen

	uses edi,ebx



	mov edi,[pString]

	mov ebx,[cbLen]

	dec ebx

	or ebx,ebx

	jns >P1

	mov ebx,edi



	:

	mov al,[ebx]

	inc ebx

	or al,al

	jnz <

	sub ebx,edi

	sub ebx,2

	P1:



	mov al,[edi+ebx]

	or al,20h

	cmp al,"h"

	jne >

		dec ebx

	:



	xor ecx,ecx

	xor eax,eax

	xor edx,edx

	L1:

		mov edx,[edi+ebx]

		and edx,0FFh

		cmp edx,"x"

		je >L3

		sub edx,"0"

		js >L3

		cmp edx,9

		jle >L2

			and edx,07h

			add edx,9

		L2:

		shl edx,cl

		or eax,edx

		add ecx,4

		dec ebx

	jns <L1

	L3:



	RET



ENDF