add Jaguar RISC versions

asm_unpackers/unpack_jagrisc_fast.js

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+;;; -*-asm-*-
+;;; ukpr unpacker for Atari Jaguar RISC. (quick version)
+
+;;; lyxass syntax
+
+
+; input:
+;;; R20 : packed buffer
+;;; R21 : output buffer
+;;; r30 : return address
+;;;
+;;; Register usage (destroyed!)
+;;; r0-r17,r20,r21
+;;;
+
+DST		REG 21
+SRC		REG 20
+
+	REGTOP 17
+LR_save		REG 99
+LR_save2	REG 99
+GETBIT		REG 99
+GETLENGTH	REG 99
+LITERAL		REG 99
+LOOP		REG 99
+index		REG 99
+bit_pos		REG 99
+state		REG 99
+prev_was_match	REG 99
+offset		REG 99
+prob		reg 99
+byte		REG 99
+ndata		reg 99
+PROBS		reg 99
+tmp2		reg 2
+tmp1		REG 1
+tmp0		REG 0
+
+	REGMAP
+
+upkr_probs	equ $200
+
+SIZEOF_PROBS	EQU 1+255+1+2*32+2*32
+
+unupkr::
+	move	LR,LR_save
+	movei	#$80808080,tmp0
+	movei	#upkr_probs,PROBS
+	movei	#SIZEOF_PROBS,tmp2
+	move	PROBS,tmp1
+.init	store	tmp0,(tmp1)
+	subq	#4,tmp2
+	jr	pl,.init
+	addq	#4,tmp1
+
+	loadb	(SRC),ndata
+	addq	#1,SRC
+	moveq	#0,offset
+	moveq	#0,state
+	movei	#getlength,GETLENGTH
+	movei	#getbit,GETBIT
+.looppc	move	PC,LOOP
+	addq	#.loop-.looppc,LOOP
+	move	pc,LITERAL
+	jr	.start
+	addq	#6,LITERAL
+
+.literal
+	moveq	#1,byte
+	move	pc,LR
+	jr	.into
+	addq	#6,LR		; LR = .getbit
+.getbit
+	addc	byte,byte
+.into
+	btst	#8,byte
+	jump	eq,(GETBIT)
+	move	byte,index
+
+	storeb	byte,(DST)
+	addq	#1,DST
+.start
+	moveq	#0,prev_was_match
+
+.loop
+	moveq	#0,index
+	BL	(GETBIT)
+	jump	cc,(LITERAL)
+	addq	#14,LR
+	cmpq	#1,prev_was_match
+	jr	eq,.newoff
+	shlq	#8,r0
+	jump	(GETBIT)
+	move	r0,index
+	jr	cc,.oldoff
+	shlq	#8,r0
+.newoff
+	addq	#1,r0		; r0 = 257
+	BL	(GETLENGTH)
+	subq	#1,r0
+	move	r0,offset
+	jump	eq,(LR_save)
+	nop
+.oldoff
+	movei	#257+64,r0
+	BL	(GETLENGTH)
+
+	move	DST,r2
+	move	DST,r1
+	or	offset,r2
+	btst	#0,r2
+	moveq	#1,prev_was_match
+	jr	ne,.cpymatch1
+	sub	offset,r1
+.cpymatch2
+	loadw	(r1),r2
+	addqt	#2,r1
+	subq	#2,r0
+	storew	r2,(DST)
+	jump	eq,(LOOP)
+	addqt	#2,DST
+	jr	pl,.cpymatch2
+	nop
+	jump	(LOOP)
+	subq	#1,DST
+
+.cpymatch1
+	loadb	(r1),r2
+	subq	#1,r0
+	addqt	#1,r1
+	storeb	r2,(DST)
+	jr	ne,.cpymatch1
+	addq	#1,DST
+
+	jump	(LOOP)
+//->	nop
+
+getlength:
+	move	LR,LR_save2
+	moveq	#0,byte
+	move	r0,index
+	moveq	#0,bit_pos
+	move	pc,LR
+	jump	(GETBIT)
+	addq	#6,LR
+.gl
+	jr	cc,.exit
+	addq	#8,LR		; => return to "sh ..."
+	jump	(GETBIT)
+	nop
+	sh	bit_pos,r0
+	subq	#1,bit_pos	; sh < 0 => shift left!
+	or	r0,byte
+	jump	(GETBIT)
+	subq	#8,LR
+.exit
+	moveq	#1,r0
+	sh	bit_pos,r0
+	jump	(LR_save2)
+	or	byte,r0
+
+.newbyte:
+	move	ndata,r2
+	shlq	#8,state
+	loadb	(SRC),ndata
+	or	r2,state
+	addq	#1,SRC
+	move	state,r2
+	shrq	#12,r2
+	jr	ne,.done
+	move	state,r2
+	jr	.newbyte
+getbit
+	move	state,r2
+	move	PROBS,r1
+	add	index,r1		; r1 = &probs[index]
+	shrq	#12,r2
+	loadb	(r1),prob
+	jr	eq,.newbyte
+	move	state,r2
+.done
+	move	state,r0
+	shlq	#24,r2
+	shrq	#8,r0		; sh
+	shrq	#24,r2		; sl
+	cmp	prob,r2
+	addqt	#1,index
+	jr	cs,.one
+	mult	prob,r0
+
+	;; state -= ((state >> 8) + 1)*prob
+	;; prob -= (prob+8)>>4
+	move	prob,r2
+	add	prob,r0
+	addq	#8,r2
+	sub	r0,state
+	shrq	#4,r2
+	moveq	#0,r0
+	sub	r2,prob
+	shrq	#1,r0		; C = 0, r0 = 0
+	jump	(LR)
+	storeb	prob,(r1)
+
+.one
+	;; state = (state >> 8)*prob+(state & 0xff)
+	;; prob += (256 + 8 - prob) >> 4
+	move	r2,state
+	movei	#256+8,r2
+	add	r0,state
+	sub	prob,r2		; 256-prob+8
+	shrq	#4,r2
+	add	r2,prob
+
+	moveq	#3,r0
+	storeb	prob,(r1)
+	jump	(LR)
+	shrq	#1,r0		; C = 0, r0 = 1