/* x_store.s - Motorola 68040 FP storage 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	x_storesa 3.2 1/24/91	__x_store --- store operand to memory or register	Used by underflow and overflow handlers.	a6 = points to fp value to be stored.		Copyright (C) Motorola, Inc. 1990			All Rights Reserved	THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF MOTOROLA	The copyright notice above does not evidence any	actual or intended publication of such source code.X_STORE	idnt    2,1 Motorola 040 Floating Point Software Package	section	8NOMANUAL*/fpreg_mask:	.byte	0x80,0x40,0x20,0x10,0x08,0x04,0x02,0x01#include "fpsp040E.h"|	xref	__x_mem_write|	xref	__x_get_fline|	xref	__x_g_opcls|	xref	__x_g_dfmtou|	xref	__x_reg_dest	.globl	__x_dest_ext	.globl	__x_dest_dbl	.globl	__x_dest_sgl	.text	.globl	__x_store__x_store:	btst	#E3,a6@(E_BYTE)	jeq 	E1_stoE3_sto:	movel	a6@(CMDREG3B),d0	bfextu	d0{#6:#3},d0		| isolate dest. reg from cmdreg3bsto_fp:	lea	fpreg_mask,a1	moveb	a1@(d0:w),d0		| convert reg# to dynamic register mask	tstb	a0@(LOCAL_SGN)	jeq 	is_pos	bset	#sign_bit,a0@(LOCAL_EX)is_pos:	fmovemx	a0@,d0		| move to correct register||	if fp0-fp3 is being modified, we must put a copy|	in the USER_FPn variable on the stack because all exception|	handlers restore fp0-fp3 from there.|	cmpb	#0x80,d0	jne 	not_fp0	fmovemx fp0-fp0,a6@(USER_FP0)	rtsnot_fp0:	cmpb	#0x40,d0	jne 	not_fp1	fmovemx fp1-fp1,a6@(USER_FP1)	rtsnot_fp1:	cmpb	#0x20,d0	jne 	not_fp2	fmovemx fp2-fp2,a6@(USER_FP2)	rtsnot_fp2:	cmpb	#0x10,d0	jne 	not_fp3	fmovemx fp3-fp3,a6@(USER_FP3)	rtsnot_fp3:	rtsE1_sto:	bsrl	__x_g_opcls		| returns opclass in d0	cmpib	#3,d0	jeq 	opc011		| branch if opclass 3	movel	a6@(CMDREG1B),d0	bfextu	d0{#6:#3},d0	| extract destination register	jra 	sto_fpopc011:	bsrl	__x_g_dfmtou	| returns dest format in d0|				| ext=00, sgl=01, dbl=10	movel	a0,a1		| save source addr in a1	movel	a6@(EXC_EA),a0	| get the address	cmpil	#0,d0		| if dest format is extended	jeq 	__x_dest_ext	| then branch	cmpil	#1,d0		| if dest format is single	jeq 	__x_dest_sgl	| then branch||	fall through to __x_dest_dbl|||	__x_dest_dbl --- write double precision value to user space||Input|	a0 -> destination address|	a1 -> source in extended precision|Output|	a0 -> destroyed|	a1 -> destroyed|	d0 -> 0||Changes extended precision to double precision.| Note: no attempt is made to round the extended value to double.|	dbl_sign = ext_sign|	dbl_exp = ext_exp - 0x3fff(ext bias) + 0x7ff(dbl bias)|	get rid of ext integer bit|	dbl_mant = ext_mant{62:12}||	    	---------------   ---------------    ---------------|  extended ->  |s|    exp    |   |1| ms mant   |    | ls mant     ||	    	---------------   ---------------    ---------------|	   	 95	    64    63 62	      32      31     11	  0|				     |			     ||				     |			     ||				     |			     ||		 	             v   		     v|	    		      ---------------   ---------------|  double   ->  	      |s|exp| mant  |   |  mant       ||	    		      ---------------   ---------------|	   	 	      63     51   32   31	       0|__x_dest_dbl:	clrl	d0		| clear d0	movew	a1@(LOCAL_EX),d0	| get exponent	subw	#0x3fff,d0	| subtract extended precision bias	cmpw	#0x4000,d0	| check if inf	jeq 	inf		| if so, special case	addw	#0x3ff,d0	| add double precision bias	swap	d0		| d0 now in upper word	lsll	#4,d0		| d0 now in proper place for dbl prec exp	tstb	a1@(LOCAL_SGN)	jeq 	get_mant	| if postive, go process mantissa	bset	#31,d0		| if negative, put in sign information|				|  before continuing	jra 	get_mant	| go process mantissainf:	movel	#0x7ff00000,d0	| load dbl inf exponent	clrl	a1@(LOCAL_HI)	| clear msb	tstb	a1@(LOCAL_SGN)	jeq 	dbl_inf		| if positive, go ahead and write it	bset	#31,d0		| if negative put in sign informationdbl_inf:	movel	d0,a1@(LOCAL_EX)	| put the new exp back on the stack	jra 	dbl_wrtget_mant:	movel	a1@(LOCAL_HI),d1	| get ms mantissa	bfextu	d1{#1:#20},d1	| get upper 20 bits of ms	orl	d1,d0		| put these bits in ms word of double	movel	d0,a1@(LOCAL_EX)	| put the new exp back on the stack	movel	a1@(LOCAL_HI),d1	| get ms mantissa	movel	#21,d0		| load shift count	lsll	d0,d1		| put lower 11 bits in upper bits	movel	d1,a1@(LOCAL_HI)	| build lower lword in memory	movel	a1@(LOCAL_LO),d1	| get ls mantissa	bfextu	d1{#0:#21},d0	| get ls 21 bits of double	orl	d0,a1@(LOCAL_HI)	| put them in double resultdbl_wrt:	movel	#0x8,d0		| byte count for double precision number	exg	a0,a1		| a0=supervisor source, a1=user dest	bsrl	__x_mem_write	/* | move the number to the user's memory */	rts||	__x_dest_sgl --- write single precision value to user space||Input|	a0 -> destination address|	a1 -> source in extended precision||Output|	a0 -> destroyed|	a1 -> destroyed|	d0 -> 0||Changes extended precision to single precision.|	sgl_sign = ext_sign|	sgl_exp = ext_exp - 0x3fff(ext bias) + 0x7f(sgl bias)|	get rid of ext integer bit|	sgl_mant = ext_mant{62:12}||	    	---------------   ---------------    ---------------|  extended ->  |s|    exp    |   |1| ms mant   |    | ls mant     ||	    	---------------   ---------------    ---------------|	   	 95	    64    63 62	   40 32      31     12	  0|				     |	   ||				     |	   ||				     |	   ||		 	             v     v|	    		      ---------------|  single   ->  	      |s|exp| mant  ||	    		      ---------------|	   	 	      31     22     0|__x_dest_sgl:	clrl	d0	movew	a1@(LOCAL_EX),d0	| get exponent	subw	#0x3fff,d0	| subtract extended precision bias	cmpw	#0x4000,d0	| check if inf	jeq 	__x_sinf		| if so, special case	addw	#0x7f,d0		| add single precision bias	swap	d0		| put exp in upper word of d0	lsll	#7,d0		| shift it into single exp bits	tstb	a1@(LOCAL_SGN)	jeq 	get_sman	| if positive, continue	bset	#31,d0		| if negative, put in sign first	jra 	get_sman	| get mantissa__x_sinf:	movel	#0x7f800000,d0	| load single inf exp to d0	tstb	a1@(LOCAL_SGN)	jeq 	sgl_wrt		| if positive, continue	bset	#31,d0		| if negative, put in sign info	jra 	sgl_wrtget_sman:	movel	a1@(LOCAL_HI),d1	| get ms mantissa	bfextu	d1{#1:#23},d1	| get upper 23 bits of ms	orl	d1,d0		| put these bits in ms word of singlesgl_wrt:	movel	d0,a6@(L_SCR1)	| put the new exp back on the stack	movel	#0x4,d0		| byte count for single precision number	tstl	a0		| users destination address	jeq 	sgl_Dn		| destination is a data register	exg	a0,a1		| a0=supervisor source, a1=user dest	lea	a6@(L_SCR1),a0	| point a0 to data	bsrl	__x_mem_write	/* | move the number to the user's memory */	rtssgl_Dn:	bsrl	__x_get_fline	| returns fline word in d0	andw	#0x7,d0		| isolate register number	movel	d0,d1		| d1 has size:reg formatted for __x_reg_dest	orl	#0x10,d1		| reg_dest wants size added to reg#	jra 	__x_reg_dest	| size is X, rts in __x_reg_dest will|				| return to caller of __x_dest_sgl__x_dest_ext:	tstb	a1@(LOCAL_SGN)	| put back sign into exponent word	jeq 	dstx_cont	bset	#sign_bit,a1@(LOCAL_EX)dstx_cont:	clrb	a1@(LOCAL_SGN)	| clear out the sign byte	movel	#0x0c,d0		| byte count for extended number	exg	a0,a1		| a0=supervisor source, a1=user dest	bsrl	__x_mem_write	/* | move the number to the user's memory */	rts|	end