/* sgetem.s - Motorola 68040 FP exponent and mantissa routines (EXC) *//* Copyright 1991-1993 Wind River Systems, Inc. */	.data	.globl	_copyright_wind_river	.long	_copyright_wind_river/*modification history--------------------01e,21jul93,kdl  added .text (SPR #2372).01d,23aug92,jcf  changed bxxx to jxx.01c,26may92,rrr  the tree shuffle01b,10jan92,kdl  added modification history; general cleanup.01a,15aug91,kdl  original version, from Motorola FPSP v2.0.*//*DESCRIPTION	sgetemsa 3.1 12/10/90	The entry point sGETEXP returns the exponent portion	of the input argument.  The exponent bias is removed	and the exponent value is returned as an extended	precision number in fp0.  sGETEXPD handles denormalized	numbers.	The entry point sGETMAN extracts the mantissa of the	input argument.  The mantissa is converted to an	extended precision number and returned in fp0.  The	range of the result is [1.0 - 2.0).	Input:  Double-extended number X in the ETEMP space in		the floating-point save stack.	Output:	The functions return exp(X) or man(X) in fp0.	Modified: fp0.		Copyright (C) Motorola, Inc. 1990			All Rights Reserved	THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF MOTOROLA	The copyright notice above does not evidence any	actual or intended publication of such source code.SGETEM	idnt	2,1 Motorola 040 Floating Point Software Package	section 8NOMANUAL*/#include "fpsp040E.h"|	xref	__x_nrm_set|| This entry point is used by the unimplemented instruction exception| handler.  It points a0 to the input operand.||||	SGETEXP|	.text	.globl	__x_sgetexp__x_sgetexp:	movew	a0@(LOCAL_EX),d0	| get the exponent	bclr	#15,d0			| clear the sign bit	subw	#0x3fff,d0		| subtract off the bias	fmovew  d0,fp0			| move the exp to fp0	rts	.globl	__x_sgetexpd__x_sgetexpd:	bclr	#sign_bit,a0@(LOCAL_EX)	bsrl	__x_nrm_set		| normalize (exp will go negative)	movew	a0@(LOCAL_EX),d0	| load resulting exponent into d0	subw	#0x3fff,d0		| subtract off the bias	fmovew	d0,fp0			| move the exp to fp0	rts||| This entry point is used by the unimplemented instruction exception| handler.  It points a0 to the input operand.||||	SGETMAN||| For normalized numbers, leave the mantissa alone, simply load| with an exponent of +/- 0x3fff.|	.globl	__x_sgetman__x_sgetman:	movel	a6@(USER_FPCR),d0	andil	#0xffffff00,d0		| clear rounding precision and mode	fmovel	d0,fpcr			| this fpcr setting is used by the 882	movew	a0@(LOCAL_EX),d0	| get the exp (really just want sign bit)	orw	#0x7fff,d0		| clear old exp	bclr	#14,d0	 		| make it the new exp +-3fff	movew	d0,a0@(LOCAL_EX)	| move the sign # exp back to fsave stack	fmovex	a0@,fp0	| put new value back in fp0	rts|| For denormalized numbers, shift the mantissa until the j-bit = 1,| then load the exponent with +/1 0x3fff.|	.globl	__x_sgetmand__x_sgetmand:	movel	a0@(LOCAL_HI),d0	| load ms mant in d0	movel	a0@(LOCAL_LO),d1	| load ls mant in d1	bsrl	shft			| shift mantissa bits till msbit is set	movel	d0,a0@(LOCAL_HI)	| put ms mant back on stack	movel	d1,a0@(LOCAL_LO)	| put ls mant back on stack	jra 	__x_sgetman||	SHFT||	Shifts the mantissa bits until msbit is set.|	input:|		ms mantissa part in d0|		ls mantissa part in d1|	output:|		shifted bits in d0 and d1shft:	tstl	d0			| if any bits set in ms mant	jne 	upper			| then branch|					| else no bits set in ms mant	tstl	d1			| test if any bits set in ls mant	jne 	cont			| if set then continue	jra 	shft_end		| else returncont:	movel	d3,a7@-			| save d3	exg	d0,d1			| shift ls mant to ms mant	bfffo	d0{#0:#32},d3		| find first 1 in ls mant to d0	lsll	d3,d0			| shift first 1 to int bit in ms mant	movel	a7@+,d3			| restore d3	jra 	shft_endupper:	moveml	d3/d5/d6,a7@-		| save registers	bfffo	d0{#0:#32},d3		| find first 1 in ls mant to d0	lsll	d3,d0			| shift ms mant until j-bit is set	movel	d1,d6			| save ls mant in d6	lsll	d3,d1			| shift ls mant by count	movel	#32,d5	subl	d3,d5			| sub 32 from shift for ls mant	lsrl	d5,d6			| shift off all bits but those that will|					| be shifted into ms mant	orl	d6,d0			| shift the ls mant bits into ms mant	moveml	a7@+,d3/d5/d6		| restore registersshft_end:	rts|	end