Category : C Source Code
Archive   : LHA211S.ZIP
Filename : MAKETBL_.ASM

;***********************************************
; maketbl_.asm -- makes decoding table
;***********************************************
page 0, 128

include amscls.inc
$_init GEN

TEXT segment byte public 'CODE'
TEXT ends

DATA segment word public 'DATA'
DATA ends

BSS segment word public 'DATA'
extrn nchar:word
extrn bitlen:word
extrn tablebits:word
extrn table:word
extrn avail_mt:word
extrn len_cnt:word
extrn start:word
extrn weight:word

extrn right_:word
extrn left_:word
extrn BROKENARC_:byte
extrn error_:near
BSS ends

DGROUP group DATA, BSS

TEXT segment byte public 'CODE'
assume cs:TEXT, ds:DGROUP
;---------------------------------------------------------------
; void make_table(short nchar, uchar bitlen[],
; ax bx
; short tablebits, ushort table[])
; cx dx
;---------------------------------------------------------------
public make_table_
make_table_ proc near
push cx
push dx
push si
push di
push bp

mov nchar, ax
shl ax, 1
mov avail_mt, ax
mov bitlen, bx
mov tablebits, cx
mov table, dx

push ds
pop es
cld

; /* clear len_cnt */
xor ax, ax
mov cx, 16
mov di, offset DGROUP:len_cnt + 2
rep stosw

; /* count bitlen into len_cnt */
xor bx, bx
mov cx, nchar
mov si, bitlen
$_do
mov bl, [si]
inc si
shl bx, 1
inc len_cnt[bx]
$_until

; /* initialize weight, start, table */
mov cx, tablebits
mov bp, 1
shl bp, cl
mov bx, offset DGROUP:len_cnt + 2
mov si, offset DGROUP:weight + 2
mov di, offset DGROUP:start + 2
mov ax, table
$_do
stosw
mov dx, [bx]
add bx, 2
shl dx, cl
add ax, dx
shr bp, 1
mov [si], bp
add si, 2
$_until
push ax
sub ax, table
mov cl, 15
sub cx, tablebits
shl ax, cl
shl bp, cl
$_do
stosw
mov dx, [bx]
add bx, 2
shl dx, cl
add ax, dx
mov [si], bp
add si, 2
dec cx
$_until , Z
$_if , NZ
mov ax, offset DGROUP:BROKENARC_
xor bx, bx
call error_
$_endif
pop di
mov ax, di
sub ax, table
shr ax, 1
mov bx, 1
mov cx, tablebits
shl bx, cl
mov cx, bx
sub cx, ax
xor ax, ax
rep stosw

; /* make table & additional tree */
xor ax, ax
$_do
mov si, ax
add si, bitlen
mov bl, [si]

or bl, bl
jz make_table_1
xor bh, bh

mov dx, bx
shl bx, 1
mov di, start[bx]
mov cx, weight[bx]
$_if , BE
rep stosw
mov start[bx], di
$_else
add start[bx], cx

mov si, di
mov bx, tablebits
mov cl, 16
sub cl, bl

shr di, cl
shl di, 1
add di, table

mov cl, bl
shl si, cl

xor cx, cx
mov cl, dl
sub cx, tablebits
; /* ‚‚³ n ‚Ì tree ‚ðì‚é */
$_do
$_if , E
; /* Ž}‚ª‚Ü‚¾‰„‚Ñ‚Ä‚¢‚È‚¯‚ê‚΍ì‚é */
mov bx, avail_mt
mov right_[bx], 0
mov left_[bx], 0
;; shr bx, 1
mov [di], bx
add avail_mt, 2
$_endif
mov di, [di]
;; shl di, 1
$_if , C
add di, offset DGROUP:right_
$_else
add di, offset DGROUP:left_
$_endif
$_until
mov [di], ax
$_endif
make_table_1:
inc ax
$_until , AE

pop bp
pop di
pop si
pop dx
pop cx
ret
make_table_ endp
TEXT ends
end