4.3BSD-Reno/src/sys/tahoemath/Ksfnorm.s

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/*	Ksfnorm.s	1.3	86/01/05	*/

#include "../tahoemath/fp.h"
#include "../tahoemath/Kfp.h"
#include "../tahoe/SYS.h"

/*
 * Ksfnorm(hfs)
 */
	.text
ENTRY(Ksfnorm, R6|R5|R4|R3|R2)
	clrl	r1
	movl	r0,r4		/* copy to temporary. */
	jeql	retzero
	clrl	r3		/* r3 - pos of m.s.b */
inr00:	ffs	r4,r6
	incl	r6
	addl2	r6,r3
	shrl	r6,r4,r4
	jneq	inr00

cmpshift:
				/* compute the shift (r4). */
	subl3	r3,$HID_POS,r4
	jlss	shiftr		/* if less then zero we shift right. */
	shll	r4,r0,r0	/* else we shift left. */
	subl2	r4,r2		/* uodate exponent. */
	jleq	underflow	/* if less then 0 (biased) it is underflow. */
	jmp	combine		/* go to combine exponent and fraction. */
shiftr:
	mnegl	r4,r4
	shrl	r4,r0,r0	/* shift right. */
	addl2	r4,r2		/* update exponent */
	cmpl	r2,$256
	jgeq	overflow	/* check for overflow. */
combine:
	andl2	$CLEARHID,r0	/* clear the hidden bit. */
	shal	$EXPSHIFT,r2,r2	/* shift the exponent to its proper place. */
	orl2	r2,r0
	ret

underflow:
	orl2	$HFS_UNDF,*4(fp)	
	ret

overflow:
	orl2	$HFS_OVF,*4(fp)
	ret
retzero:
	clrl	r0
	ret