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Revision 1.1, Tue Mar 4 16:07:07 2008 UTC (16 years, 2 months ago) by nbrk
Branch point for: MAIN

Initial revision

*	$OpenBSD: util.sa,v 1.2 1996/05/29 21:05:45 niklas Exp $
*	$NetBSD: util.sa,v 1.3 1994/10/26 07:50:20 cgd Exp $

*	MOTOROLA MICROPROCESSOR & MEMORY TECHNOLOGY GROUP
*	M68000 Hi-Performance Microprocessor Division
*	M68040 Software Package 
*
*	M68040 Software Package Copyright (c) 1993, 1994 Motorola Inc.
*	All rights reserved.
*
*	THE SOFTWARE is provided on an "AS IS" basis and without warranty.
*	To the maximum extent permitted by applicable law,
*	MOTOROLA DISCLAIMS ALL WARRANTIES WHETHER EXPRESS OR IMPLIED,
*	INCLUDING IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A
*	PARTICULAR PURPOSE and any warranty against infringement with
*	regard to the SOFTWARE (INCLUDING ANY MODIFIED VERSIONS THEREOF)
*	and any accompanying written materials. 
*
*	To the maximum extent permitted by applicable law,
*	IN NO EVENT SHALL MOTOROLA BE LIABLE FOR ANY DAMAGES WHATSOEVER
*	(INCLUDING WITHOUT LIMITATION, DAMAGES FOR LOSS OF BUSINESS
*	PROFITS, BUSINESS INTERRUPTION, LOSS OF BUSINESS INFORMATION, OR
*	OTHER PECUNIARY LOSS) ARISING OF THE USE OR INABILITY TO USE THE
*	SOFTWARE.  Motorola assumes no responsibility for the maintenance
*	and support of the SOFTWARE.  
*
*	You are hereby granted a copyright license to use, modify, and
*	distribute the SOFTWARE so long as this entire notice is retained
*	without alteration in any modified and/or redistributed versions,
*	and that such modified versions are clearly identified as such.
*	No licenses are granted by implication, estoppel or otherwise
*	under any patents or trademarks of Motorola, Inc.

*
*	util.sa 3.7 7/29/91
*
*	This file contains routines used by other programs.
*
*	ovf_res: used by overflow to force the correct
*		 result. ovf_r_k, ovf_r_x2, ovf_r_x3 are 
*		 derivatives of this routine.
*	get_fline: get user's opcode word
*	g_dfmtou: returns the destination format.
*	g_opcls: returns the opclass of the float instruction.
*	g_rndpr: returns the rounding precision. 
*	reg_dest: write byte, word, or long data to Dn
*

UTIL	IDNT    2,1 Motorola 040 Floating Point Software Package

	section	8

	include	fpsp.h

	xref	mem_read

	xdef	g_dfmtou
	xdef	g_opcls
	xdef	g_rndpr
	xdef	get_fline
	xdef	reg_dest

*
* Final result table for ovf_res. Note that the negative counterparts
* are unnecessary as ovf_res always returns the sign separately from
* the exponent.
*					;+inf
EXT_PINF	dc.l	$7fff0000,$00000000,$00000000,$00000000	
*					;largest +ext
EXT_PLRG	dc.l	$7ffe0000,$ffffffff,$ffffffff,$00000000	
*					;largest magnitude +sgl in ext
SGL_PLRG	dc.l	$407e0000,$ffffff00,$00000000,$00000000	
*					;largest magnitude +dbl in ext
DBL_PLRG	dc.l	$43fe0000,$ffffffff,$fffff800,$00000000	
*					;largest -ext

tblovfl:
	dc.l	EXT_RN
	dc.l	EXT_RZ
	dc.l	EXT_RM
	dc.l	EXT_RP
	dc.l	SGL_RN
	dc.l	SGL_RZ
	dc.l	SGL_RM
	dc.l	SGL_RP
	dc.l	DBL_RN
	dc.l	DBL_RZ
	dc.l	DBL_RM
	dc.l	DBL_RP
	dc.l	error
	dc.l	error
	dc.l	error
	dc.l	error


*
*	ovf_r_k --- overflow result calculation
*
* This entry point is used by kernel_ex.  
*
* This forces the destination precision to be extended
*
* Input:	operand in ETEMP
* Output:	a result is in ETEMP (internal extended format)
*
	xdef	ovf_r_k
ovf_r_k:
	lea	ETEMP(a6),a0	;a0 points to source operand	
	bclr.b	#sign_bit,ETEMP_EX(a6)
	sne	ETEMP_SGN(a6)	;convert to internal IEEE format

*
*	ovf_r_x2 --- overflow result calculation
*
* This entry point used by x_ovfl.  (opclass 0 and 2)
*
* Input		a0  points to an operand in the internal extended format
* Output	a0  points to the result in the internal extended format
*
* This sets the round precision according to the user's FPCR unless the
* instruction is fsgldiv or fsglmul or fsadd, fdadd, fsub, fdsub, fsmul,
* fdmul, fsdiv, fddiv, fssqrt, fsmove, fdmove, fsabs, fdabs, fsneg, fdneg.
* If the instruction is fsgldiv of fsglmul, the rounding precision must be
* extended.  If the instruction is not fsgldiv or fsglmul but a force-
* precision instruction, the rounding precision is then set to the force
* precision.

	xdef	ovf_r_x2
ovf_r_x2:
	btst.b	#E3,E_BYTE(a6)		;check for nu exception
	beq.l	ovf_e1_exc		;it is cu exception
ovf_e3_exc:
	move.w	CMDREG3B(a6),d0		;get the command word
	andi.w	#$00000060,d0		;clear all bits except 6 and 5
	cmpi.l	#$00000040,d0
	beq.l	ovff_sgl		;force precision is single
	cmpi.l	#$00000060,d0
	beq.l	ovff_dbl		;force precision is double
	move.w	CMDREG3B(a6),d0		;get the command word again
	andi.l	#$7f,d0			;clear all except operation
	cmpi.l	#$33,d0			
	beq.l	ovf_fsgl		;fsglmul or fsgldiv
	cmpi.l	#$30,d0
	beq.l	ovf_fsgl		
	bra	ovf_fpcr		;instruction is none of the above
*					;use FPCR
ovf_e1_exc:
	move.w	CMDREG1B(a6),d0		;get command word
	andi.l	#$00000044,d0		;clear all bits except 6 and 2
	cmpi.l	#$00000040,d0
	beq.l	ovff_sgl		;the instruction is force single
	cmpi.l	#$00000044,d0
	beq.l	ovff_dbl		;the instruction is force double
	move.w	CMDREG1B(a6),d0		;again get the command word
	andi.l	#$0000007f,d0		;clear all except the op code
	cmpi.l	#$00000027,d0
	beq.l	ovf_fsgl		;fsglmul
	cmpi.l 	#$00000024,d0
	beq.l	ovf_fsgl		;fsgldiv
	bra	ovf_fpcr		;none of the above, use FPCR
* 
*
* Inst is either fsgldiv or fsglmul.  Force extended precision.
*
ovf_fsgl:
	clr.l	d0
	bra.b	ovf_res

ovff_sgl:
	move.l	#$00000001,d0		;set single
	bra.b	ovf_res
ovff_dbl:
	move.l	#$00000002,d0		;set double
	bra.b	ovf_res
*
* The precision is in the fpcr.
*
ovf_fpcr:
	bfextu	FPCR_MODE(a6){0:2},d0 ;set round precision
	bra.b	ovf_res
	
*
*
*	ovf_r_x3 --- overflow result calculation
*
* This entry point used by x_ovfl. (opclass 3 only)
*
* Input		a0  points to an operand in the internal extended format
* Output	a0  points to the result in the internal extended format
*
* This sets the round precision according to the destination size.
*
	xdef	ovf_r_x3
ovf_r_x3:
	bsr	g_dfmtou	;get dest fmt in d0{1:0}
*				;for fmovout, the destination format
*				;is the rounding precision

*
*	ovf_res --- overflow result calculation
*
* Input:
*	a0 	points to operand in internal extended format
* Output:
*	a0 	points to result in internal extended format
*
	xdef	ovf_res
ovf_res:
	lsl.l	#2,d0		;move round precision to d0{3:2}
	bfextu	FPCR_MODE(a6){2:2},d1 ;set round mode
	or.l	d1,d0		;index is fmt:mode in d0{3:0}
	lea.l	tblovfl,a1	;load a1 with table address
	move.l	(a1,d0*4),a1	;use d0 as index to the table
	jmp	(a1)		;go to the correct routine
*
*case DEST_FMT = EXT
*
EXT_RN:
	lea.l	EXT_PINF,a1	;answer is +/- infinity
	bset.b	#inf_bit,FPSR_CC(a6)
	bra	set_sign	;now go set the sign	
EXT_RZ:
	lea.l	EXT_PLRG,a1	;answer is +/- large number
	bra	set_sign	;now go set the sign
EXT_RM:
	tst.b	LOCAL_SGN(a0)	;if negative overflow
	beq.b	e_rm_pos
e_rm_neg:
	lea.l	EXT_PINF,a1	;answer is negative infinity
	or.l	#neginf_mask,USER_FPSR(a6)
	bra	end_ovfr
e_rm_pos:
	lea.l	EXT_PLRG,a1	;answer is large positive number
	bra	end_ovfr
EXT_RP:
	tst.b	LOCAL_SGN(a0)	;if negative overflow
	beq.b	e_rp_pos
e_rp_neg:
	lea.l	EXT_PLRG,a1	;answer is large negative number
	bset.b	#neg_bit,FPSR_CC(a6)
	bra	end_ovfr
e_rp_pos:
	lea.l	EXT_PINF,a1	;answer is positive infinity
	bset.b	#inf_bit,FPSR_CC(a6)
	bra	end_ovfr
*
*case DEST_FMT = DBL
*
DBL_RN:
	lea.l	EXT_PINF,a1	;answer is +/- infinity
	bset.b	#inf_bit,FPSR_CC(a6)
	bra	set_sign
DBL_RZ:
	lea.l	DBL_PLRG,a1	;answer is +/- large number
	bra	set_sign	;now go set the sign
DBL_RM:
	tst.b	LOCAL_SGN(a0)	;if negative overflow
	beq.b	d_rm_pos
d_rm_neg:
	lea.l	EXT_PINF,a1	;answer is negative infinity
	or.l	#neginf_mask,USER_FPSR(a6)
	bra	end_ovfr	;inf is same for all precisions (ext,dbl,sgl)
d_rm_pos:
	lea.l	DBL_PLRG,a1	;answer is large positive number
	bra	end_ovfr
DBL_RP:
	tst.b	LOCAL_SGN(a0)	;if negative overflow
	beq.b	d_rp_pos
d_rp_neg:
	lea.l	DBL_PLRG,a1	;answer is large negative number
	bset.b	#neg_bit,FPSR_CC(a6)
	bra	end_ovfr
d_rp_pos:
	lea.l	EXT_PINF,a1	;answer is positive infinity
	bset.b	#inf_bit,FPSR_CC(a6)
	bra	end_ovfr
*
*case DEST_FMT = SGL
*
SGL_RN:
	lea.l	EXT_PINF,a1	;answer is +/-  infinity
	bset.b	#inf_bit,FPSR_CC(a6)
	bra.b	set_sign
SGL_RZ:
	lea.l	SGL_PLRG,a1	;anwer is +/- large number
	bra.b	set_sign
SGL_RM:
	tst.b	LOCAL_SGN(a0)	;if negative overflow
	beq.b	s_rm_pos
s_rm_neg:
	lea.l	EXT_PINF,a1	;answer is negative infinity
	or.l	#neginf_mask,USER_FPSR(a6)
	bra.b	end_ovfr
s_rm_pos:
	lea.l	SGL_PLRG,a1	;answer is large positive number
	bra.b	end_ovfr
SGL_RP:
	tst.b	LOCAL_SGN(a0)	;if negative overflow
	beq.b	s_rp_pos
s_rp_neg:
	lea.l	SGL_PLRG,a1	;answer is large negative number
	bset.b	#neg_bit,FPSR_CC(a6)
	bra.b	end_ovfr
s_rp_pos:
	lea.l	EXT_PINF,a1	;answer is postive infinity
	bset.b	#inf_bit,FPSR_CC(a6)
	bra.b	end_ovfr

set_sign:
	tst.b	LOCAL_SGN(a0)	;if negative overflow
	beq.b	end_ovfr
neg_sign:
	bset.b	#neg_bit,FPSR_CC(a6)

end_ovfr:
	move.w	LOCAL_EX(a1),LOCAL_EX(a0) ;do not overwrite sign
	move.l	LOCAL_HI(a1),LOCAL_HI(a0)
	move.l	LOCAL_LO(a1),LOCAL_LO(a0)
	rts


*
*	ERROR
*
error:
	rts
*
*	get_fline --- get f-line opcode of interrupted instruction
*
*	Returns opcode in the low word of d0.
*
get_fline:
	move.l	USER_FPIAR(a6),a0	;opcode address
	clr.l	-(a7)		;reserve a word on the stack
	lea.l	2(a7),a1	;point to low word of temporary
	move.l	#2,d0		;count
	bsr.l	mem_read
	move.l	(a7)+,d0
	rts
*
* 	g_rndpr --- put rounding precision in d0{1:0}
*	
*	valid return codes are:
*		00 - extended 
*		01 - single
*		10 - double
*
* begin
* get rounding precision (cmdreg3b{6:5})
* begin
*  case	opclass = 011 (move out)
*	get destination format - this is the also the rounding precision
*
*  case	opclass = 0x0
*	if E3
*	    *case RndPr(from cmdreg3b{6:5} = 11  then RND_PREC = DBL
*	    *case RndPr(from cmdreg3b{6:5} = 10  then RND_PREC = SGL
*	     case RndPr(from cmdreg3b{6:5} = 00 | 01
*		use precision from FPCR{7:6}
*			case 00 then RND_PREC = EXT
*			case 01 then RND_PREC = SGL
*			case 10 then RND_PREC = DBL
*	else E1
*	     use precision in FPCR{7:6}
*	     case 00 then RND_PREC = EXT
*	     case 01 then RND_PREC = SGL
*	     case 10 then RND_PREC = DBL
* end
*
g_rndpr:
	bsr.w	g_opcls		;get opclass in d0{2:0}
	cmp.w	#$0003,d0	;check for opclass 011
	bne.b	op_0x0

*
* For move out instructions (opclass 011) the destination format
* is the same as the rounding precision.  Pass results from g_dfmtou.
*
	bsr.w 	g_dfmtou	
	rts
op_0x0:
	btst.b	#E3,E_BYTE(a6)
	beq.l	unf_e1_exc	;branch to e1 underflow
unf_e3_exc:
	move.l	CMDREG3B(a6),d0	;rounding precision in d0{10:9}
	bfextu	d0{9:2},d0	;move the rounding prec bits to d0{1:0}
	cmpi.l	#$2,d0
	beq.l	unff_sgl	;force precision is single
	cmpi.l	#$3,d0		;force precision is double
	beq.l	unff_dbl
	move.w	CMDREG3B(a6),d0	;get the command word again
	andi.l	#$7f,d0		;clear all except operation
	cmpi.l	#$33,d0			
	beq.l	unf_fsgl	;fsglmul or fsgldiv
	cmpi.l	#$30,d0
	beq.l	unf_fsgl	;fsgldiv or fsglmul
	bra	unf_fpcr
unf_e1_exc:
	move.l	CMDREG1B(a6),d0	;get 32 bits off the stack, 1st 16 bits
*				;are the command word
	andi.l	#$00440000,d0	;clear all bits except bits 6 and 2
	cmpi.l	#$00400000,d0
	beq.l	unff_sgl	;force single
	cmpi.l	#$00440000,d0	;force double
	beq.l	unff_dbl
	move.l	CMDREG1B(a6),d0	;get the command word again
	andi.l	#$007f0000,d0	;clear all bits except the operation
	cmpi.l	#$00270000,d0
	beq.l	unf_fsgl	;fsglmul
	cmpi.l	#$00240000,d0
	beq.l	unf_fsgl	;fsgldiv
	bra	unf_fpcr

*
* Convert to return format.  The values from cmdreg3b and the return
* values are:
*	cmdreg3b	return	     precision
*	--------	------	     ---------
*	  00,01		  0		ext
*	   10		  1		sgl
*	   11		  2		dbl
* Force single
*
unff_sgl:
	move.l	#1,d0		;return 1
	rts
*
* Force double
*
unff_dbl:
	move.l	#2,d0		;return 2
	rts
*
* Force extended
*
unf_fsgl:
	clr.l	d0		
	rts
*
* Get rounding precision set in FPCR{7:6}.
*
unf_fpcr:
	move.l	USER_FPCR(a6),d0 ;rounding precision bits in d0{7:6}
	bfextu	d0{24:2},d0	;move the rounding prec bits to d0{1:0}
	rts
*
*	g_opcls --- put opclass in d0{2:0}
*
g_opcls:
	btst.b	#E3,E_BYTE(a6)
	beq.b	opc_1b		;if set, go to cmdreg1b
opc_3b:
	clr.l	d0		;if E3, only opclass 0x0 is possible
	rts
opc_1b:
	move.l	CMDREG1B(a6),d0
	bfextu	d0{0:3},d0	;shift opclass bits d0{31:29} to d0{2:0}
	rts
*
*	g_dfmtou --- put destination format in d0{1:0}
*
*	If E1, the format is from cmdreg1b{12:10}
*	If E3, the format is extended.
*
*	Dest. Fmt.	
*		extended  010 -> 00
*		single    001 -> 01
*		double    101 -> 10
*
g_dfmtou:
	btst.b	#E3,E_BYTE(a6)
	beq.b	op011
	clr.l	d0		;if E1, size is always ext
	rts
op011:
	move.l	CMDREG1B(a6),d0
	bfextu	d0{3:3},d0	;dest fmt from cmdreg1b{12:10}
	cmp.b	#1,d0		;check for single
	bne.b	not_sgl
	move.l	#1,d0
	rts
not_sgl:
	cmp.b	#5,d0		;check for double
	bne.b	not_dbl
	move.l	#2,d0
	rts
not_dbl:
	clr.l	d0		;must be extended
	rts

*
*
* Final result table for unf_sub. Note that the negative counterparts
* are unnecessary as unf_sub always returns the sign separately from
* the exponent.
*					;+zero
EXT_PZRO	dc.l	$00000000,$00000000,$00000000,$00000000	
*					;+zero
SGL_PZRO	dc.l	$3f810000,$00000000,$00000000,$00000000	
*					;+zero
DBL_PZRO	dc.l	$3c010000,$00000000,$00000000,$00000000	
*					;smallest +ext denorm
EXT_PSML	dc.l	$00000000,$00000000,$00000001,$00000000	
*					;smallest +sgl denorm
SGL_PSML	dc.l	$3f810000,$00000100,$00000000,$00000000	
*					;smallest +dbl denorm
DBL_PSML	dc.l	$3c010000,$00000000,$00000800,$00000000	
*
*	UNF_SUB --- underflow result calculation
*
* Input:
*	d0 	contains round precision
*	a0	points to input operand in the internal extended format
*
* Output:
*	a0 	points to correct internal extended precision result.
*

tblunf:
	dc.l	uEXT_RN
	dc.l	uEXT_RZ
	dc.l	uEXT_RM
	dc.l	uEXT_RP
	dc.l	uSGL_RN
	dc.l	uSGL_RZ
	dc.l	uSGL_RM
	dc.l	uSGL_RP
	dc.l	uDBL_RN
	dc.l	uDBL_RZ
	dc.l	uDBL_RM
	dc.l	uDBL_RP
	dc.l	uDBL_RN
	dc.l	uDBL_RZ
	dc.l	uDBL_RM
	dc.l	uDBL_RP

	xdef	unf_sub
unf_sub:
	lsl.l	#2,d0		;move round precision to d0{3:2}
	bfextu	FPCR_MODE(a6){2:2},d1 ;set round mode
	or.l	d1,d0		;index is fmt:mode in d0{3:0}
	lea.l	tblunf,a1	;load a1 with table address
	move.l	(a1,d0*4),a1	;use d0 as index to the table
	jmp	(a1)		;go to the correct routine
*
*case DEST_FMT = EXT
*
uEXT_RN:
	lea.l	EXT_PZRO,a1	;answer is +/- zero
	bset.b	#z_bit,FPSR_CC(a6)
	bra	uset_sign	;now go set the sign	
uEXT_RZ:
	lea.l	EXT_PZRO,a1	;answer is +/- zero
	bset.b	#z_bit,FPSR_CC(a6)
	bra	uset_sign	;now go set the sign
uEXT_RM:
	tst.b	LOCAL_SGN(a0)	;if negative underflow
	beq.b	ue_rm_pos
ue_rm_neg:
	lea.l	EXT_PSML,a1	;answer is negative smallest denorm
	bset.b	#neg_bit,FPSR_CC(a6)
	bra	end_unfr
ue_rm_pos:
	lea.l	EXT_PZRO,a1	;answer is positive zero
	bset.b	#z_bit,FPSR_CC(a6)
	bra	end_unfr
uEXT_RP:
	tst.b	LOCAL_SGN(a0)	;if negative underflow
	beq.b	ue_rp_pos
ue_rp_neg:
	lea.l	EXT_PZRO,a1	;answer is negative zero
	ori.l	#negz_mask,USER_FPSR(a6)
	bra	end_unfr
ue_rp_pos:
	lea.l	EXT_PSML,a1	;answer is positive smallest denorm
	bra	end_unfr
*
*case DEST_FMT = DBL
*
uDBL_RN:
	lea.l	DBL_PZRO,a1	;answer is +/- zero
	bset.b	#z_bit,FPSR_CC(a6)
	bra	uset_sign
uDBL_RZ:
	lea.l	DBL_PZRO,a1	;answer is +/- zero
	bset.b	#z_bit,FPSR_CC(a6)
	bra	uset_sign	;now go set the sign
uDBL_RM:
	tst.b	LOCAL_SGN(a0)	;if negative overflow
	beq.b	ud_rm_pos
ud_rm_neg:
	lea.l	DBL_PSML,a1	;answer is smallest denormalized negative
	bset.b	#neg_bit,FPSR_CC(a6)
	bra	end_unfr
ud_rm_pos:
	lea.l	DBL_PZRO,a1	;answer is positive zero
	bset.b	#z_bit,FPSR_CC(a6)
	bra	end_unfr
uDBL_RP:
	tst.b	LOCAL_SGN(a0)	;if negative overflow
	beq.b	ud_rp_pos
ud_rp_neg:
	lea.l	DBL_PZRO,a1	;answer is negative zero
	ori.l	#negz_mask,USER_FPSR(a6)
	bra	end_unfr
ud_rp_pos:
	lea.l	DBL_PSML,a1	;answer is smallest denormalized negative
	bra	end_unfr
*
*case DEST_FMT = SGL
*
uSGL_RN:
	lea.l	SGL_PZRO,a1	;answer is +/- zero
	bset.b	#z_bit,FPSR_CC(a6)
	bra.b	uset_sign
uSGL_RZ:
	lea.l	SGL_PZRO,a1	;answer is +/- zero
	bset.b	#z_bit,FPSR_CC(a6)
	bra.b	uset_sign
uSGL_RM:
	tst.b	LOCAL_SGN(a0)	;if negative overflow
	beq.b	us_rm_pos
us_rm_neg:
	lea.l	SGL_PSML,a1	;answer is smallest denormalized negative
	bset.b	#neg_bit,FPSR_CC(a6)
	bra.b	end_unfr
us_rm_pos:
	lea.l	SGL_PZRO,a1	;answer is positive zero
	bset.b	#z_bit,FPSR_CC(a6)
	bra.b	end_unfr
uSGL_RP:
	tst.b	LOCAL_SGN(a0)	;if negative overflow
	beq.b	us_rp_pos
us_rp_neg:
	lea.l	SGL_PZRO,a1	;answer is negative zero
	ori.l	#negz_mask,USER_FPSR(a6)
	bra.b	end_unfr
us_rp_pos:
	lea.l	SGL_PSML,a1	;answer is smallest denormalized positive
	bra.b	end_unfr

uset_sign:
	tst.b	LOCAL_SGN(a0)	;if negative overflow
	beq.b	end_unfr
uneg_sign:
	bset.b	#neg_bit,FPSR_CC(a6)

end_unfr:
	move.w	LOCAL_EX(a1),LOCAL_EX(a0) ;be careful not to overwrite sign
	move.l	LOCAL_HI(a1),LOCAL_HI(a0)
	move.l	LOCAL_LO(a1),LOCAL_LO(a0)
	rts
*
*	reg_dest --- write byte, word, or long data to Dn
*
*
* Input:
*	L_SCR1: Data 
*	d1:     data size and dest register number formatted as:
*
*	32		5    4     3     2     1     0
*       -----------------------------------------------
*       |        0        |    Size   |  Dest Reg #   |
*       -----------------------------------------------
*
*	Size is:
*		0 - Byte
*		1 - Word
*		2 - Long/Single
*
pregdst:
	dc.l	byte_d0
	dc.l	byte_d1
	dc.l	byte_d2
	dc.l	byte_d3
	dc.l	byte_d4
	dc.l	byte_d5
	dc.l	byte_d6
	dc.l	byte_d7
	dc.l	word_d0
	dc.l	word_d1
	dc.l	word_d2
	dc.l	word_d3
	dc.l	word_d4
	dc.l	word_d5
	dc.l	word_d6
	dc.l	word_d7
	dc.l	long_d0
	dc.l	long_d1
	dc.l	long_d2
	dc.l	long_d3
	dc.l	long_d4
	dc.l	long_d5
	dc.l	long_d6
	dc.l	long_d7

reg_dest:
	lea.l	pregdst,a0
	move.l	(a0,d1*4),a0
	jmp	(a0)

byte_d0:
	move.b	L_SCR1(a6),USER_D0+3(a6)
	rts
byte_d1:
	move.b	L_SCR1(a6),USER_D1+3(a6)
	rts
byte_d2:
	move.b	L_SCR1(a6),d2
	rts
byte_d3:
	move.b	L_SCR1(a6),d3
	rts
byte_d4:
	move.b	L_SCR1(a6),d4
	rts
byte_d5:
	move.b	L_SCR1(a6),d5
	rts
byte_d6:
	move.b	L_SCR1(a6),d6
	rts
byte_d7:
	move.b	L_SCR1(a6),d7
	rts
word_d0:
	move.w	L_SCR1(a6),USER_D0+2(a6)
	rts
word_d1:
	move.w	L_SCR1(a6),USER_D1+2(a6)
	rts
word_d2:
	move.w	L_SCR1(a6),d2
	rts
word_d3:
	move.w	L_SCR1(a6),d3
	rts
word_d4:
	move.w	L_SCR1(a6),d4
	rts
word_d5:
	move.w	L_SCR1(a6),d5
	rts
word_d6:
	move.w	L_SCR1(a6),d6
	rts
word_d7:
	move.w	L_SCR1(a6),d7
	rts
long_d0:
	move.l	L_SCR1(a6),USER_D0(a6)
	rts
long_d1:
	move.l	L_SCR1(a6),USER_D1(a6)
	rts
long_d2:
	move.l	L_SCR1(a6),d2
	rts
long_d3:
	move.l	L_SCR1(a6),d3
	rts
long_d4:
	move.l	L_SCR1(a6),d4
	rts
long_d5:
	move.l	L_SCR1(a6),d5
	rts
long_d6:
	move.l	L_SCR1(a6),d6
	rts
long_d7:
	move.l	L_SCR1(a6),d7
	rts
	end