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Remove unused code

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Emmanuel Marty 2020-03-24 20:18:22 +01:00 committed by GitHub
parent 26a64de95e
commit 47e54ac110
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2 changed files with 16 additions and 170 deletions
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41
asm/6502/decompress_faster_v1.asm
View File

@ -29,15 +29,6 @@
; Decompression Options & Macros
;
;
; Save 6 bytes of code and 21 cycles by swapping the order
; of bytes in the 16-bit length encoding?
;
; N.B. Setting this breaks compatibility with LZSA v1.2
;
LZSA_SWAP_LEN16 = 0
;
; Choose size over space (within sane limits)?
;
@ -80,14 +71,6 @@ LZSA_SHORT_LZ = 1
LZSA_SHORT_LZ = 0
}
;
; Assume that we're decompessing from a large multi-bank
; compressed data file, and that the next bank may need to
; paged in when a page-boundary is crossed.
;
LZSA_FROM_BANK = 0
;
; Macro to increment the source pointer to the next page.
;
@ -95,14 +78,8 @@ LZSA_FROM_BANK = 0
; has been crossed, and a new bank should be paged in.
;
!if LZSA_FROM_BANK {
!macro LZSA_INC_PAGE {
jsr lzsa1_next_page
}
} else {
!macro LZSA_INC_PAGE {
!macro LZSA_INC_PAGE {
inc <lzsa_srcptr + 1
}
}
;
@ -159,9 +136,6 @@ LZSA_DST_HI = $FF
; Args: lzsa_dstptr = ptr to output buffer
; Uses: lots!
;
; If compiled with LZSA_FROM_BANK, then lzsa_srcptr should be within the bank
; window range.
;
DECOMPRESS_LZSA1_FAST:
lzsa1_unpack: ldy #0 ; Initialize source index.
@ -355,14 +329,6 @@ lzsa1_unpack: ldy #0 ; Initialize source index.
.extra_byte: inx
jmp lzsa1_get_byte ; So rare, this can be slow!
!if LZSA_SWAP_LEN16 {
.extra_word: jsr lzsa1_get_byte ; So rare, this can be slow!
tax
beq .finished ; Length-hi == 0 at EOF.
} else {
.extra_word: jsr lzsa1_get_byte ; So rare, this can be slow!
pha
jsr lzsa1_get_byte ; So rare, this can be slow!
@ -371,8 +337,6 @@ lzsa1_unpack: ldy #0 ; Initialize source index.
pla ; Length-lo.
rts
}
lzsa1_get_byte:
lda (lzsa_srcptr),y ; Subroutine version for when
inc <lzsa_srcptr + 0 ; inlining isn't advantageous.
@ -381,9 +345,6 @@ lzsa1_get_byte:
lzsa1_next_page:
inc <lzsa_srcptr + 1 ; Inc & test for bank overflow.
!if LZSA_FROM_BANK {
bmi lzsa1_next_bank ; Change for target hardware!
}
rts
.finished: pla ; Length-lo.

145
asm/6502/decompress_faster_v2.asm
View File

@ -29,24 +29,6 @@
; Decompression Options & Macros
;
;
; Save 7 bytes of code, and 21 cycles every time that a
; 16-bit length is decoded?
;
; N.B. Setting this breaks compatibility with LZSA v1.2
;
LZSA_SWAP_LEN16 = 0
;
; Save 3 bytes of code, and 4 or 8 cycles when decoding
; an offset?
;
; N.B. Setting this breaks compatibility with LZSA v1.2
;
LZSA_SWAP_XZY = 0
;
; Choose size over space (within sane limits)?
;
@ -77,14 +59,6 @@ LZSA_SHORT_CP = 1
LZSA_SHORT_CP = 0
}
;
; Assume that we're decompressing from a large multi-bank
; compressed data file, and that the next bank may need to
; paged in when a page-boundary is crossed.
;
LZSA_FROM_BANK = 0
;
; We will read from or write to $FFFF. This prevents the
; use of the "INC ptrhi / BNE" trick and reduces speed.
@ -96,14 +70,8 @@ LZSA_USE_FFFF = 0
; Macro to increment the source pointer to the next page.
;
!if LZSA_FROM_BANK {
!macro LZSA_INC_PAGE {
jsr lzsa2_next_page
}
} else {
!macro LZSA_INC_PAGE {
!macro LZSA_INC_PAGE {
inc <lzsa_srcptr + 1
}
}
;
@ -189,15 +157,12 @@ LZSA_DST_HI = $FF
; Args: lzsa_dstptr = ptr to output buffer
; Uses: lots!
;
; If compiled with LZSA_FROM_BANK, then lzsa_srcptr should be within the bank
; window range.
;
DECOMPRESS_LZSA2_FAST:
lzsa2_unpack: ldy #0 ; Initialize source index.
sty <lzsa_nibflg ; Initialize nibble buffer.
!if (LZSA_FROM_BANK | LZSA_NO_INLINE | LZSA_USE_FFFF) = 0 {
!if (LZSA_NO_INLINE | LZSA_USE_FFFF) = 0 {
beq .cp_length ; always taken
.incsrc1:
@ -223,7 +188,7 @@ lzsa2_unpack: ldy #0 ; Initialize source index.
.cp_length: ldx #$00 ; Hi-byte of length or offset.
!if (LZSA_FROM_BANK | LZSA_NO_INLINE | LZSA_USE_FFFF) {
!if (LZSA_NO_INLINE | LZSA_USE_FFFF) {
+LZSA_GET_SRC
@ -262,7 +227,7 @@ lzsa2_unpack: ldy #0 ; Initialize source index.
sta (lzsa_dstptr),y
inc <lzsa_srcptr + 0
!if (LZSA_FROM_BANK | LZSA_NO_INLINE | LZSA_USE_FFFF) {
!if (LZSA_NO_INLINE | LZSA_USE_FFFF) {
bne .skip1
inc <lzsa_srcptr + 1
@ -322,70 +287,13 @@ lzsa2_unpack: ldy #0 ; Initialize source index.
}
!if LZSA_SWAP_XZY {
;
; Shorter and faster path with NEW order of bits.
;
; STD NEW
; ================================
; xyz xzy
; 00z 0z0 5-bit offset
; 01z 0z1 9-bit offset
; 10z 1z0 13-bit offset
; 110 101 16-bit offset
; 111 111 repeat offset
; NVZ for a BIT instruction
;
; N.B. Saves 3 bytes in code length.
; get5 and get13 are 8 cycles faster.
; get9, get16, and rep are 4 cycles faster.
;
.lz_offset: lda #$20 ; Y bit in lzsa_cmdbuf.
bit <lzsa_cmdbuf
bmi .get_13_16_rep
bne .get_9_bits
.get_5_bits: dex ; X=$FF
.get_13_bits: +LZSA_GET_NIBL ; Always returns with CS.
bvc .get_5_skip
clc
.get_5_skip: rol ; Shift into position, set C.
cpx #$00 ; X=$FF for a 5-bit offset.
bne .set_offset
sbc #2 ; Subtract 512 because 13-bit
tax ; offset starts at $FE00.
bne .get_low8 ; Always NZ from previous TAX.
.get_9_bits: dex ; X=$FF if VC, X=$FE if VS.
bvc .get_low8
dex
bvs .get_low8 ; Always VS from previous BIT.
.get_13_16_rep: beq .get_13_bits ; Shares code with 5-bit path.
.get_16_rep: bvs .lz_length ; Repeat previous offset.
} else {
;
; Slower and longer path with STD order of bits.
;
; STD NEW
; ================================
; xyz xzy
; 00z 0z0 5-bit offset
; 01z 0z1 9-bit offset
; 10z 1z0 13-bit offset
; 110 101 16-bit offset
; 111 111 repeat offset
; NVZ for a BIT instruction
;
; N.B. Costs 3 bytes in code length.
; get5 and get13 are 8 cycles slower.
; get9, get16, and rep are 4 cycles slower.
;
; xyz
; 00z 5-bit offset
; 01z 9-bit offset
; 10z 13-bit offset
; 110 16-bit offset
; 111 repeat offset
.lz_offset: lda <lzsa_cmdbuf
asl
@ -417,8 +325,6 @@ lzsa2_unpack: ldy #0 ; Initialize source index.
.get_16_rep: bmi .lz_length ; Repeat previous offset.
}
;
; Copy bytes from decompressed window.
;
@ -430,7 +336,7 @@ lzsa2_unpack: ldy #0 ; Initialize source index.
.get_low8x: tax
.get_low8:
!if (LZSA_FROM_BANK | LZSA_NO_INLINE | LZSA_USE_FFFF) {
!if (LZSA_NO_INLINE | LZSA_USE_FFFF) {
+LZSA_GET_SRC ; Get lo-byte of offset.
@ -491,7 +397,7 @@ lzsa2_unpack: ldy #0 ; Initialize source index.
jmp .cp_length ; Loop around to the beginning.
!if (LZSA_FROM_BANK | LZSA_NO_INLINE | LZSA_USE_FFFF) = 0 {
!if (LZSA_NO_INLINE | LZSA_USE_FFFF) = 0 {
.incsrc3:
inc <lzsa_srcptr + 1
@ -526,13 +432,6 @@ lzsa2_unpack: ldy #0 ; Initialize source index.
bcc .got_length
beq .finished
!if LZSA_SWAP_LEN16 {
.word_length: jsr lzsa2_get_byte ; So rare, this can be slow!
tax
} else {
.word_length: jsr lzsa2_get_byte ; So rare, this can be slow!
pha
jsr lzsa2_get_byte ; So rare, this can be slow!
@ -540,8 +439,6 @@ lzsa2_unpack: ldy #0 ; Initialize source index.
pla
rts
}
lzsa2_get_byte:
lda (lzsa_srcptr),y ; Subroutine version for when
inc <lzsa_srcptr + 0 ; inlining isn't advantageous.
@ -550,9 +447,6 @@ lzsa2_get_byte:
lzsa2_next_page:
inc <lzsa_srcptr + 1 ; Inc & test for bank overflow.
!if LZSA_FROM_BANK {
bmi lzsa2_next_bank ; Change for target hardware!
}
rts
.finished: pla ; Decompression completed, pop
@ -571,7 +465,7 @@ lzsa2_get_nibble:
bcs .got_nibble
inc <lzsa_nibflg ; Reset the flag.
!if (LZSA_FROM_BANK | LZSA_NO_INLINE | LZSA_USE_FFFF) {
!if (LZSA_NO_INLINE | LZSA_USE_FFFF) {
+LZSA_GET_SRC
@ -590,10 +484,6 @@ lzsa2_get_nibble:
lsr
lsr
!if LZSA_SWAP_XZY {
sec ; Offset code relies on CS.
}
.got_nibble: ora #$F0
rts
@ -601,7 +491,7 @@ lzsa2_get_nibble:
lzsa2_new_nibble:
inc <lzsa_nibflg ; Reset the flag.
!if (LZSA_FROM_BANK | LZSA_NO_INLINE | LZSA_USE_FFFF) {
!if (LZSA_NO_INLINE | LZSA_USE_FFFF) {
+LZSA_GET_SRC
@ -619,16 +509,11 @@ lzsa2_new_nibble:
lsr
lsr
lsr
!if LZSA_SWAP_XZY {
sec ; Offset code relies on CS.
}
rts
}
!if (LZSA_FROM_BANK | LZSA_NO_INLINE | LZSA_USE_FFFF) = 0 {
!if (LZSA_NO_INLINE | LZSA_USE_FFFF) = 0 {
.incsrc4:
inc <lzsa_srcptr + 1