;Adobe Helvetica normal
;-------------------------------------------------
;Errechnet die gerundete Wurzel eines 64Bit Integerwertes
;-------------------------------------------------
;The result is a rounded squareroot of a 64-Bit integer value
;-------------------------------------------------

;	Code for the best assembler: The Netwide Assembler: NASM
;	Copyright (C) 2004 by Sebastian Beck; sebastian.bw@freenet.de

;	Wenn Sie eine Spende machen wollen, fragen Sie mich über E-Mail
;	nach meiner Bankverbindung.

;	If you want to make a donation, please question me by e-mail for
;	my banking connection.

;	This program is free software; you can redistribute it and/or modify
;	it under the terms of the GNU General Public License as
;	published by the Free Software Foundation.

;	This program is distributed in the hope that it will be useful,
;	but WITHOUT ANY WARRANTY; without even the implied warranty of
;	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;	GNU	General Public License for more details.
;	http://www.gnu.org/

;-------------------------------------------------
;%include "./INC/sqrt64.inc"

;To your global or the declaration of the calling process.

;Wert			dd	0,0	;value	-unchanged
;Ergebnis		dd	0,0	;result
;-------------------------------------------------

sqrt64:

section .text
	pushad

	bsr	ecx,[Wert+4]
	jnz	.a2
	mov	ecx,0
	jmp	.a4
.a2:
	add	ecx,32
	jmp	.a8
.a4:
	bsr	ecx,[Wert]
	jnz	.a8
	mov	dword[Ergebnis],0
	jmp	.ende
.a8:
	shr	ecx,1		;geteilt durch 2
	mov	ebx,0
	bts	ebx,ecx
.b4
	cmp	ecx,0
	je	.c2
	dec	ecx
	bts	ebx,ecx
	mov	edx,0
	mov	eax,ebx
	mul	ebx
	cmp	edx,[Wert+4]
	je	.b6
	jb	.b4
.b5:
	btr	ebx,ecx
	jmp	.b4
.b6:
	cmp	eax,[Wert]
	jb	.b4
	jz	.c2
	jmp	.b5
.c2
	mov	edx,0
	mov	eax,ebx
	inc	eax
	jc	.c8
	mul	ebx
	cmp	edx,[Wert+4]
	je	.c4
	jb	.c6
	mov	[Ergebnis],ebx
	jmp	.ende
.c4:
	cmp	eax,[Wert]
	jb	.c6

	mov	[Ergebnis],ebx
	jmp	.ende
.c6:

	inc	ebx
.c8:
	mov	[Ergebnis],ebx

.ende:
	popad
	ret