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(lz) *

This commit is contained in:
neauoire 2023-11-18 12:19:30 -08:00
parent a6343d0697
commit 9101bda743
2 changed files with 67 additions and 5 deletions
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6
cli/lz/ulzenc.c
View File

@ -36,15 +36,17 @@ uxn_lz_compress(const void *input, int input_size)
/* DEBUG: printf("%04x %04x \n", dict_len, string_len); */
/* Iterate through the dictionary */
for(dict = in - dict_len, match_len = 0; dict_len; dict++, dict_len -= 1) {
match_len = 0;
dict = in - dict_len;
for(; dict_len; dict++, dict_len -= 1) {
/* Find common prefix length with the string */
/* If we reach the end of the string, this is the best possible match. End. */
for(i = 0;; i++) {
if(i == string_len) {
match_len = i;
dict_best = dict;
goto done_search;
}
/* ^ If we reach the end of the string, this is the best possible match. End. */
/* Dictionary repeats if we hit the end */
if(in[i] != dict[i % dict_len])
break;

64
cli/lz/ulzenc.tal
View File

@ -8,6 +8,7 @@
@src $30
@dst $30
@ptr $1
@match-len $2
|0100
@ -34,6 +35,10 @@
( halt ) #800f DEO
BRK
@<append-byte> ( byte -- )
.output-ptr LDZ2 INC2k .output-ptr STZ2 STA
JMP2r
@uxn_lz_compress ( input* length* -- )
ADD2k NIP2 SWP2
&w ( -- )
@ -44,8 +49,63 @@
SUB2k #3fff #0004 ADD2 LTH2k ?{ SWP2 }
POP2 ,&string-len STR2
( | itterate through the dictionary )
[ LIT2 &dict-len $2 ] phex #2018 DEO
[ LIT2 &string-len $2 ] phex #0a18 DEO
#0000 .match-len STZ2
[ LIT2 &dict-len $2 ] SUB2k .dict STZ2
( | create a few inlines )
DUP2 ,&in STR2
&for1 ( dict-len != 0 )
( Find common prefix length with the string )
#0000
&for2 ( i != 0 )
( If we reach the end of the string, it's the best possible match. )
DUP2 [ LIT2 &string-len $2 ] NEQ2 ?{
DUP2 .match-len STZ2
.dict LDZ2 .dict-best STZ2
POP2 POP2 !&done-search }
( Dictionary repeats if we hit the end )
( in[i] != dict[i % dict_len] break; )
DUP2 [ LIT2 &in $2 ] ADD2 LDA2
OVR2 ,&dict-len LDR2 DIV2k MUL2 SUB2
.dict LDZ2 ADD2 LDA2 NEQ2 ?&end
INC2 ORAk ?&for2
&end
( i > match_len )
DUP2 .match-len LDZ2 GTH2 #00 EQU ?{
DUP2 .match-len STZ2
.dict-len LDZ2 .dict STZ2 }
POP2
.dict LDZ2 INC2 .dict STZ2
#0001 SUB2 ORAk ?&for1
POP2
&done-search ( -- )
( CPY )
.match-len LDZ2 #0004 LTH2 ?&no-cpy
( More numeric range: treat 0 as 4, 1 as 5, etc. )
.match-len LDZ2 #0004 SUB2 .match-ctl STZ2
( CPY2 )
.match-ctl LDZ2 #003f GTH2 ?&cpy2
( CPY1 )
( *output_ptr++ = match_ctl | 0x80; )
.match-ctl LDZ2 #0080 ORA2 <append-byte>
!&cpy-resume
&cpy2
( TODO )
&cpy-resume
( *output_ptr++ = in - dict_best - 1; )
DUP2 .dict-best LDZ2 #0001 SUB2 SUB2 <append-byte>
&no-cpy
( LIT )
phex #2018 DEO
phex #0a18 DEO
( TODO: remove me!! ) INC2 NEQ2k ?&w
JMP2r