|
|
|
@ -60,8 +60,8 @@ |
|
|
|
; 3. This notice may not be removed or altered from any source distribution. |
|
|
|
; |
|
|
|
|
|
|
|
; #DEFINE BACKWARD_DECOMPRESS ; uncomment for data compressed with option -b (+5 bytes, -3% speed) |
|
|
|
; #DEFINE AVOID_SELFMODIFYING_CODE ; uncomment to disallow self-modifying code (-1 byte, -4% speed) |
|
|
|
; #DEFINE BACKWARD_DECOMPRESS ; uncomment for data compressed with option -b (+5 bytes, -3% speed) |
|
|
|
; #DEFINE AVOID_SELFMODIFYING_CODE ; uncomment to disallow self-modifying code (-1 byte, -4% speed) |
|
|
|
|
|
|
|
#IFNDEF BACKWARD_DECOMPRESS |
|
|
|
|
|
|
|
@ -79,7 +79,7 @@ |
|
|
|
|
|
|
|
#DEFINE ADD_OFFSET \ |
|
|
|
#DEFCONT \ ld a,e \ sub l \ ld l,a |
|
|
|
#DEFCONT \ ld a,d \ sbc h \ ld h,a ; 6*4 = 24t / 6 bytes |
|
|
|
#DEFCONT \ ld a,d \ sbc h \ ld h,a ; 6*4 = 24t / 6 bytes |
|
|
|
|
|
|
|
#DEFINE BLOCKCOPY \ |
|
|
|
#DEFCONT \ lddr |
|
|
|
@ -118,7 +118,7 @@ MatchLen: and %00000111 \ add a,2 \ cp 9 |
|
|
|
call z,ExtendedCode |
|
|
|
|
|
|
|
CopyMatch: ld c,a |
|
|
|
push hl ; BC = len, DE = dest, HL = -offset, SP -> [src] |
|
|
|
push hl ; BC = len, DE = dest, HL = -offset, SP -> [src] |
|
|
|
|
|
|
|
#IFNDEF AVOID_SELFMODIFYING_CODE |
|
|
|
PrevOffset .EQU $+1 \ ld hl,0 |
|
|
|
@ -126,8 +126,8 @@ PrevOffset .EQU $+1 \ ld hl,0 |
|
|
|
push ix \ pop hl |
|
|
|
#ENDIF |
|
|
|
ADD_OFFSET |
|
|
|
BLOCKCOPY ; BC = 0, DE = dest |
|
|
|
pop hl ; HL = src |
|
|
|
BLOCKCOPY ; BC = 0, DE = dest |
|
|
|
pop hl ; HL = src |
|
|
|
|
|
|
|
ReadToken: ld a,(hl) \ NEXT_HL \ push af |
|
|
|
and %00011000 \ jr z,NoLiterals |
|
|
|
@ -163,12 +163,16 @@ ExtendedCode: call ReadNibble \ inc a \ jr z,ExtraByte |
|
|
|
ExtraByte ld a,15 \ add a,c \ add a,(hl) \ NEXT_HL \ ret nc |
|
|
|
ld a,(hl) \ NEXT_HL |
|
|
|
ld b,(hl) \ NEXT_HL \ ret nz |
|
|
|
pop bc ; RET is not needed, because RET from ReadNibble is sufficient |
|
|
|
pop bc ; RET is not needed, because RET from ReadNibble is sufficient |
|
|
|
|
|
|
|
|
|
|
|
ReadNibble: ld c,a |
|
|
|
skipLDCA xor a \ ex af,af' \ ret m |
|
|
|
skipLDCA xor a \ nop \ ex af,af' \ ret m ; NOP for Z280 bug |
|
|
|
ld a,(hl) \ or $F0 \ ex af,af' |
|
|
|
ld a,(hl) \ NEXT_HL \ or $0F |
|
|
|
rrca \ rrca \ rrca \ rrca \ ret |
|
|
|
|
|
|
|
; The extraneous NOP instruction above is to workaround a bug in the |
|
|
|
; Z280 processor where ex af,af' can copy rather than swap the flags |
|
|
|
; register. |
|
|
|
; See https://www.retrobrewcomputers.org/forum/index.php?t=msg&goto=10183& |
|
|
|
|
Wayne Warthen
3 years ago