From 4266e712f25383a2a5dbabb0161240f8c989b9f1 Mon Sep 17 00:00:00 2001 From: Piotr Fusik Date: Sun, 12 Feb 2017 11:41:11 +0100 Subject: [PATCH] Optimize inflatemem. The new version is 30% shorter and 10% faster. It also avoids the indirect-X addressing mode, which was a problem for PC-Engine. --- libsrc/zlib/inflatemem.s | 936 +++++++++++++++++---------------------- 1 file changed, 395 insertions(+), 541 deletions(-) diff --git a/libsrc/zlib/inflatemem.s b/libsrc/zlib/inflatemem.s index b3a0510c5..27802fbff 100644 --- a/libsrc/zlib/inflatemem.s +++ b/libsrc/zlib/inflatemem.s @@ -1,43 +1,41 @@ ; -; 2003-09-21, Piotr Fusik -; 2017-02-07, Greg King +; 2017-02-12, Piotr Fusik ; ; unsigned __fastcall__ inflatemem (char* dest, const char* source); ; - -; Two "lda (0,x)" instructions can't be assembled for the PC-Engine library -; because an implied ".setdp $2000" changes $00 into a non-zero-page address. -; Therefore, this file isn't assembled for that target. -.ifndef __PCE__ +; NOTE: Be extremely careful with modifications, because this code is heavily +; optimized for size (for example assumes certain register and flag values +; when its internal routines return). Test with the gunzip65 sample. +; .export _inflatemem .import incsp2 - .importzp sp, sreg, ptr1, ptr2, ptr3, ptr4, tmp1 - - .macpack cpu + .importzp sp, sreg, ptr1, ptr2, ptr3, ptr4 ; -------------------------------------------------------------------------- ; ; Constants ; -; Maximum length of a Huffman code. -MAX_BITS = 15 - -; All Huffman trees are stored in the bitsCount, bitsPointer_l -; and bitsPointer_h arrays. There may be two trees: the literal/length tree -; and the distance tree, or just one - the temporary tree. +; Argument values for getBits. +GET_1_BIT = $81 +GET_2_BITS = $82 +GET_3_BITS = $84 +GET_4_BITS = $88 +GET_5_BITS = $90 +GET_6_BITS = $a0 +GET_7_BITS = $c0 -; Index in the mentioned arrays for the beginning of the literal/length tree -; or the temporary tree. -PRIMARY_TREE = 0 +; Huffman trees. +TREE_SIZE = 16 +PRIMARY_TREE = 0 +DISTANCE_TREE = TREE_SIZE -; Index in the mentioned arrays for the beginning of the distance tree. -DISTANCE_TREE = MAX_BITS - -; Size of each array. -TREES_SIZE = 2*MAX_BITS +; Alphabet. +LENGTH_SYMBOLS = 1+29+2 ; EOF, 29 length symbols, two unused symbols +DISTANCE_SYMBOLS = 30 +CONTROL_SYMBOLS = LENGTH_SYMBOLS+DISTANCE_SYMBOLS ; -------------------------------------------------------------------------- @@ -46,30 +44,26 @@ TREES_SIZE = 2*MAX_BITS ; ; Pointer to the compressed data. -inputPointer := ptr1 ; 2 bytes +inputPointer := ptr1 ; 2 bytes ; Pointer to the uncompressed data. -outputPointer := ptr2 ; 2 bytes +outputPointer := ptr2 ; 2 bytes ; Local variables. ; As far as there is no conflict, same memory locations are used ; for different variables. -inflateDynamicBlock_cnt := ptr3 ; 1 byte -inflateCodes_src := ptr3 ; 2 bytes -buildHuffmanTree_src := ptr3 ; 2 bytes -getNextLength_last := ptr3 ; 1 byte -getNextLength_index := ptr3+1 ; 1 byte - -buildHuffmanTree_ptr := ptr4 ; 2 bytes -fetchCode_ptr := ptr4 ; 2 bytes -getBits_tmp := ptr4 ; 1 byte - -moveBlock_len := sreg ; 2 bytes -inflateDynamicBlock_np := sreg ; 1 byte -inflateDynamicBlock_nd := sreg+1 ; 1 byte - -getBit_hold := tmp1 ; 1 byte +inflateStored_pageCounter := ptr3 ; 1 byte +inflateDynamic_symbol := ptr3 ; 1 byte +inflateDynamic_lastLength := ptr3+1 ; 1 byte + .assert ptr4 = ptr3 + 2, error, "Need three bytes for inflateDynamic_tempCodes" +inflateDynamic_tempCodes := ptr3+1 ; 3 bytes +inflateDynamic_allCodes := inflateDynamic_tempCodes+1 ; 1 byte +inflateDynamic_primaryCodes := inflateDynamic_tempCodes+2 ; 1 byte +inflateCodes_sourcePointer := ptr3 ; 2 bytes +inflateCodes_lengthMinus2 := ptr4 ; 1 byte +getBits_base := sreg ; 1 byte +getBit_buffer := sreg+1 ; 1 byte ; -------------------------------------------------------------------------- @@ -83,45 +77,59 @@ _inflatemem: sta inputPointer stx inputPointer+1 ; outputPointer = dest -.if (.cpu & CPU_ISET_65SC02) - lda (sp) ldy #1 -.else - ldy #0 - lda (sp),y - iny -.endif - sta outputPointer lda (sp),y sta outputPointer+1 + dey + lda (sp),y + sta outputPointer + +; ldy #0 + sty getBit_buffer -; ldy #1 - sty getBit_hold -inflatemem_1: +inflate_blockLoop: ; Get a bit of EOF and two bits of block type - ldx #3 - lda #0 +; ldy #0 + sty getBits_base + lda #GET_3_BITS jsr getBits lsr a ; A and Z contain block type, C contains EOF flag ; Save EOF flag php -; Go to the routine decompressing this block - jsr callExtr + bne inflateCompressed + +; Decompress a 'stored' data block. +; ldy #0 + sty getBit_buffer ; ignore bits until byte boundary + jsr getWord ; skip the length we don't need + jsr getWord ; get the two's complement length + sta inflateStored_pageCounter + bcs inflateStored_firstByte ; jmp +inflateStored_copyByte: + jsr getByte +; sec +inflateStoreByte: + jsr storeByte + bcc inflateCodes_loop +inflateStored_firstByte: + inx + bne inflateStored_copyByte + inc inflateStored_pageCounter + bne inflateStored_copyByte + +; Block decompressed. +inflate_nextBlock: plp - bcc inflatemem_1 -; C flag is set! + bcc inflate_blockLoop -; return outputPointer - dest; +; Decompression complete. +; return outputPointer - dest lda outputPointer -.if (.cpu & CPU_ISET_65SC02) - sbc (sp) ; C flag is set - ldy #1 -.else - ldy #0 - sbc (sp),y ; C flag is set +; ldy #0 +; sec + sbc (sp),y iny -.endif pha lda outputPointer+1 sbc (sp),y @@ -130,442 +138,346 @@ inflatemem_1: ; pop dest jmp incsp2 -; -------------------------------------------------------------------------- -; Go to proper block decoding routine. - -callExtr: - bne inflateCompressedBlock - -; -------------------------------------------------------------------------- -; Decompress a 'stored' data block. - -inflateCopyBlock: -; Ignore bits until byte boundary - ldy #1 - sty getBit_hold -; Get 16-bit length - ldx #inputPointer - lda (0,x) - sta moveBlock_len - lda (inputPointer),y - sta moveBlock_len+1 -; Skip the length and one's complement of it - lda #4 - clc - adc inputPointer - sta inputPointer - bcc moveBlock - inc inputPointer+1 -; jmp moveBlock - -; -------------------------------------------------------------------------- -; Copy block of length moveBlock_len from (0,x) to the output. - -moveBlock: - ldy moveBlock_len - beq moveBlock_1 -.if (.cpu & CPU_ISET_65SC02) -.else - ldy #0 -.endif - inc moveBlock_len+1 -moveBlock_1: - lda (0,x) -.if (.cpu & CPU_ISET_65SC02) - sta (outputPointer) -.else - sta (outputPointer),y -.endif - inc 0,x - bne moveBlock_2 - inc 1,x -moveBlock_2: - inc outputPointer - bne moveBlock_3 - inc outputPointer+1 -moveBlock_3: -.if (.cpu & CPU_ISET_65SC02) - dey -.else - dec moveBlock_len -.endif - bne moveBlock_1 - dec moveBlock_len+1 - bne moveBlock_1 - rts - -; -------------------------------------------------------------------------- +inflateCompressed: ; Decompress a Huffman-coded data block -; (A = 1: fixed, A = 2: dynamic). +; A=1: fixed block, initialize with fixed codes +; A=2: dynamic block, start by clearing all code lengths +; A=3: invalid compressed data, not handled in this routine + eor #2 -inflateCompressedBlock: - lsr a - bne inflateDynamicBlock -; Note: inflateDynamicBlock may assume that A = 1 - -; -------------------------------------------------------------------------- -; Decompress a Huffman-coded data block with default Huffman trees -; (defined by the DEFLATE format): -; literalCodeLength: 144 times 8, 112 times 9 -; endCodeLength: 7 -; lengthCodeLength: 23 times 7, 6 times 8 -; distanceCodeLength: 30 times 5+DISTANCE_TREE, 2 times 8 -; (two 8-bit codes from the primary tree are not used). - -inflateFixedBlock: - ldx #159 - stx distanceCodeLength+32 - lda #8 -inflateFixedBlock_1: - sta literalCodeLength-1,x - sta literalCodeLength+159-1,x - dex - bne inflateFixedBlock_1 - ldx #112 -; lda #9 -inflateFixedBlock_2: - inc literalCodeLength+144-1,x ; sta - dex - bne inflateFixedBlock_2 - ldx #24 -; lda #7 -inflateFixedBlock_3: - dec endCodeLength-1,x ; sta - dex - bne inflateFixedBlock_3 - ldx #30 - lda #5+DISTANCE_TREE -inflateFixedBlock_4: - sta distanceCodeLength-1,x - dex - bne inflateFixedBlock_4 - beq inflateCodes ; branch always - -; -------------------------------------------------------------------------- -; Decompress a Huffman-coded data block, reading Huffman trees first. - -inflateDynamicBlock: -; numberOfPrimaryCodes = 257 + getBits(5) - ldx #5 -; lda #1 - jsr getBits - sta inflateDynamicBlock_np -; numberOfDistanceCodes = 1 + getBits(5) - ldx #5 - lda #1+29+1 - jsr getBits - sta inflateDynamicBlock_nd -; numberOfTemporaryCodes = 4 + getBits(4) - lda #4 +; ldy #0 +inflateCompressed_setCodeLengths: tax - jsr getBits - sta inflateDynamicBlock_cnt -; Get lengths of temporary codes in the order stored in tempCodeLengthOrder - txa ; lda #0 - tay -inflateDynamicBlock_1: - ldx #3 ; A = 0 - jsr getBits ; does not change Y -inflateDynamicBlock_2: - ldx tempCodeLengthOrder,y - sta literalCodeLength,x - lda #0 + beq inflateCompressed_setLiteralCodeLength +; fixed Huffman literal codes: +; 144 8-bit codes +; 112 9-bit codes + lda #4 + cpy #144 + rol a +inflateCompressed_setLiteralCodeLength: + sta literalSymbolCodeLength,y + beq inflateCompressed_setControlCodeLength +; fixed Huffman control codes: +; 24 7-bit codes +; 6 8-bit codes +; 2 meaningless 8-bit codes +; 30 5-bit distance codes + lda #5+DISTANCE_TREE + cpy #LENGTH_SYMBOLS + bcs inflateCompressed_setControlCodeLength + cpy #24 + adc #$100+2-DISTANCE_TREE +inflateCompressed_setControlCodeLength: + cpy #CONTROL_SYMBOLS + bcs inflateCompressed_noControlSymbol + sta controlSymbolCodeLength,y +inflateCompressed_noControlSymbol: iny - cpy inflateDynamicBlock_cnt - bcc inflateDynamicBlock_1 - cpy #19 - bcc inflateDynamicBlock_2 - ror literalCodeLength+19 ; C flag is set, so this will set b7 -; Build the tree for temporary codes - jsr buildHuffmanTree + bne inflateCompressed_setCodeLengths -; Use temporary codes to get lengths of literal/length and distance codes - ldx #0 - ldy #1 - stx getNextLength_last -inflateDynamicBlock_3: - jsr getNextLength - sta literalCodeLength,x - inx - bne inflateDynamicBlock_3 -inflateDynamicBlock_4: - jsr getNextLength -inflateDynamicBlock_5: - sta endCodeLength,x - inx - cpx inflateDynamicBlock_np - bcc inflateDynamicBlock_4 - lda #0 - cpx #1+29 - bcc inflateDynamicBlock_5 -inflateDynamicBlock_6: - jsr getNextLength - cmp #0 - beq inflateDynamicBlock_7 - adc #DISTANCE_TREE-1 ; C flag is set -inflateDynamicBlock_7: - sta endCodeLength,x - inx - cpx inflateDynamicBlock_nd - bcc inflateDynamicBlock_6 - ror endCodeLength,x ; C flag is set, so this will set b7 -; jmp inflateCodes - -; -------------------------------------------------------------------------- -; Decompress a data block basing on given Huffman trees. + tax + beq inflateDynamic +; Decompress a block inflateCodes: jsr buildHuffmanTree -inflateCodes_1: +inflateCodes_loop: jsr fetchPrimaryCode - bcs inflateCodes_2 -; Literal code -.if (.cpu & CPU_ISET_65SC02) - sta (outputPointer) -.else - ldy #0 - sta (outputPointer),y -.endif - inc outputPointer - bne inflateCodes_1 - inc outputPointer+1 - bcc inflateCodes_1 ; branch always -; End of block -inflateCodes_ret: - rts -inflateCodes_2: - beq inflateCodes_ret -; Restore a block from the look-behind buffer - jsr getValue - sta moveBlock_len + bcc inflateStoreByte + beq inflate_nextBlock +; Copy sequence from look-behind buffer +; ldy #0 + sty getBits_base + cmp #9 + bcc inflateCodes_setSequenceLength tya - jsr getBits - sta moveBlock_len+1 +; lda #0 + cpx #1+28 + bcs inflateCodes_setSequenceLength + dex + txa + lsr a + ror getBits_base + inc getBits_base + lsr a + rol getBits_base + jsr getAMinus1BitsMax8 +; sec + adc #0 +inflateCodes_setSequenceLength: + sta inflateCodes_lengthMinus2 ldx #DISTANCE_TREE jsr fetchCode - jsr getValue - sec + cmp #4 + bcc inflateCodes_setOffsetLowByte + inc getBits_base + lsr a + jsr getAMinus1BitsMax8 +inflateCodes_setOffsetLowByte: eor #$ff - adc outputPointer - sta inflateCodes_src - php - tya + sta inflateCodes_sourcePointer + lda getBits_base + cpx #10 + bcc inflateCodes_setOffsetHighByte + lda getNPlus1Bits_mask-10,x jsr getBits - plp + clc +inflateCodes_setOffsetHighByte: eor #$ff +; clc adc outputPointer+1 - sta inflateCodes_src+1 - ldx #inflateCodes_src - jsr moveBlock - beq inflateCodes_1 ; branch always - -; -------------------------------------------------------------------------- -; Build Huffman trees basing on code lengths (in bits). -; stored in the *CodeLength arrays. -; A byte with its highest bit set marks the end. + sta inflateCodes_sourcePointer+1 + jsr copyByte + jsr copyByte +inflateCodes_copyByte: + jsr copyByte + dec inflateCodes_lengthMinus2 + bne inflateCodes_copyByte + beq inflateCodes_loop ; jmp + +inflateDynamic: +; Decompress a block reading Huffman trees first +; ldy #0 +; numberOfPrimaryCodes = 257 + getBits(5) +; numberOfDistanceCodes = 1 + getBits(5) +; numberOfTemporaryCodes = 4 + getBits(4) + ldx #3 +inflateDynamic_getHeader: + lda inflateDynamic_headerBits-1,x + jsr getBits +; sec + adc inflateDynamic_headerBase-1,x + sta inflateDynamic_tempCodes-1,x + dex + bne inflateDynamic_getHeader -buildHuffmanTree: - lda #literalCodeLength - sta buildHuffmanTree_src+1 -; Clear bitsCount and bitsPointer_l - ldy #2*TREES_SIZE+1 - lda #0 -buildHuffmanTree_1: - sta bitsCount-1,y - dey - bne buildHuffmanTree_1 - beq buildHuffmanTree_3 ; branch always -; Count number of codes of each length -buildHuffmanTree_2: - tax - inc bitsPointer_l,x - iny - bne buildHuffmanTree_3 - inc buildHuffmanTree_src+1 -buildHuffmanTree_3: - lda (buildHuffmanTree_src),y - bpl buildHuffmanTree_2 -; Calculate a pointer for each length - ldx #0 - lda #sortedCodes - clc -buildHuffmanTree_4: - sta bitsPointer_l,x - tya - sta bitsPointer_h,x - lda bitsPointer_l+1,x - adc bitsPointer_l,x ; C flag is zero - bcc buildHuffmanTree_5 - iny -buildHuffmanTree_5: - inx - cpx #TREES_SIZE - bcc buildHuffmanTree_4 - lda #>literalCodeLength - sta buildHuffmanTree_src+1 +; Get lengths of temporary codes in the order stored in inflateDynamic_tempSymbols +; ldx #0 +inflateDynamic_getTempCodeLengths: + lda #GET_3_BITS + jsr getBits + ldy inflateDynamic_tempSymbols,x + sta literalSymbolCodeLength,y ldy #0 - bcs buildHuffmanTree_9 ; branch always -; Put codes into their place in sorted table -buildHuffmanTree_6: - beq buildHuffmanTree_7 - tax - lda bitsPointer_l-1,x - sta buildHuffmanTree_ptr - lda bitsPointer_h-1,x - sta buildHuffmanTree_ptr+1 - tya - ldy bitsCount-1,x - inc bitsCount-1,x - sta (buildHuffmanTree_ptr),y - tay -buildHuffmanTree_7: - iny - bne buildHuffmanTree_9 - inc buildHuffmanTree_src+1 - ldx #MAX_BITS-1 -buildHuffmanTree_8: - lda bitsCount,x - sta literalCount,x - dex - bpl buildHuffmanTree_8 -buildHuffmanTree_9: - lda (buildHuffmanTree_src),y - bpl buildHuffmanTree_6 - rts + inx + cpx inflateDynamic_tempCodes + bcc inflateDynamic_getTempCodeLengths -; -------------------------------------------------------------------------- -; Decode next code length using temporary codes. +; Build the tree for temporary codes + jsr buildHuffmanTree -getNextLength: - stx getNextLength_index - dey - bne getNextLength_1 +; Use temporary codes to get lengths of literal/length and distance codes +; ldx #0 +; sec +inflateDynamic_decodeLength: +; C=1: literal codes +; C=0: control codes + stx inflateDynamic_symbol + php ; Fetch a temporary code jsr fetchPrimaryCode ; Temporary code 0..15: put this length - ldy #1 - cmp #16 - bcc getNextLength_2 + bpl inflateDynamic_storeLengths ; Temporary code 16: repeat last length 3 + getBits(2) times ; Temporary code 17: put zero length 3 + getBits(3) times ; Temporary code 18: put zero length 11 + getBits(7) times - tay - ldx tempExtraBits-16,y - lda tempBaseValue-16,y + tax jsr getBits - cpy #17 + cpx #GET_3_BITS + bcc inflateDynamic_code16 + beq inflateDynamic_code17 +; sec + adc #7 +inflateDynamic_code17: +; ldy #0 + sty inflateDynamic_lastLength +inflateDynamic_code16: tay - txa ; lda #0 - bcs getNextLength_2 -getNextLength_1: - lda getNextLength_last -getNextLength_2: - sta getNextLength_last - ldx getNextLength_index - rts + lda inflateDynamic_lastLength + iny + iny +inflateDynamic_storeLengths: + iny + plp + ldx inflateDynamic_symbol +inflateDynamic_storeLength: + bcc inflateDynamic_controlSymbolCodeLength + sta literalSymbolCodeLength,x + inx + cpx #1 +inflateDynamic_storeNext: + dey + bne inflateDynamic_storeLength + sta inflateDynamic_lastLength + beq inflateDynamic_decodeLength ; jmp +inflateDynamic_controlSymbolCodeLength: + cpx inflateDynamic_primaryCodes + bcc inflateDynamic_storeControl +; the code lengths we skip here were zero-initialized +; in inflateCompressed_setControlCodeLength + bne inflateDynamic_noStartDistanceTree + ldx #LENGTH_SYMBOLS +inflateDynamic_noStartDistanceTree: + ora #DISTANCE_TREE +inflateDynamic_storeControl: + sta controlSymbolCodeLength,x + inx + cpx inflateDynamic_allCodes + bcc inflateDynamic_storeNext + dey +; ldy #0 + jmp inflateCodes -; -------------------------------------------------------------------------- -; Read a code basing on the primary tree. +; Build Huffman trees basing on code lengths (in bits) +; stored in the *SymbolCodeLength arrays +buildHuffmanTree: +; Clear nBitCode_totalCount, nBitCode_literalCount, nBitCode_controlCount + tya +; lda #0 +buildHuffmanTree_clear: + sta nBitCode_clearFrom,y + iny + bne buildHuffmanTree_clear +; Count number of codes of each length +; ldy #0 +buildHuffmanTree_countCodeLengths: + ldx literalSymbolCodeLength,y + inc nBitCode_literalCount,x + inc nBitCode_totalCount,x + cpy #CONTROL_SYMBOLS + bcs buildHuffmanTree_noControlSymbol + ldx controlSymbolCodeLength,y + inc nBitCode_controlCount,x + inc nBitCode_totalCount,x +buildHuffmanTree_noControlSymbol: + iny + bne buildHuffmanTree_countCodeLengths +; Calculate offsets of symbols sorted by code length +; lda #0 + ldx #$100-3*TREE_SIZE +buildHuffmanTree_calculateOffsets: + sta nBitCode_literalOffset+3*TREE_SIZE-$100,x + clc + adc nBitCode_literalCount+3*TREE_SIZE-$100,x + inx + bne buildHuffmanTree_calculateOffsets +; Put symbols in their place in the sorted array +; ldy #0 +buildHuffmanTree_assignCode: + tya + ldx literalSymbolCodeLength,y + ldy nBitCode_literalOffset,x + inc nBitCode_literalOffset,x + sta codeToLiteralSymbol,y + tay + cpy #CONTROL_SYMBOLS + bcs buildHuffmanTree_noControlSymbol2 + ldx controlSymbolCodeLength,y + ldy nBitCode_controlOffset,x + inc nBitCode_controlOffset,x + sta codeToControlSymbol,y + tay +buildHuffmanTree_noControlSymbol2: + iny + bne buildHuffmanTree_assignCode + rts +; Read Huffman code using the primary tree fetchPrimaryCode: ldx #PRIMARY_TREE -; jmp fetchCode - -; -------------------------------------------------------------------------- -; Read a code from input basing on the tree specified in X. +; Read a code from input using the tree specified in X. ; Return low byte of this code in A. -; For the literal/length tree, the C flag is set if the code is non-literal. - +; Return C flag reset for literal code, set for length code. fetchCode: - lda #0 -fetchCode_1: +; ldy #0 + tya +fetchCode_nextBit: jsr getBit rol a inx sec - sbc bitsCount-1,x - bcs fetchCode_1 - adc bitsCount-1,x ; C flag is zero - cmp literalCount-1,x - sta fetchCode_ptr - ldy bitsPointer_l-1,x - lda bitsPointer_h-1,x - sta fetchCode_ptr+1 - lda (fetchCode_ptr),y + sbc nBitCode_totalCount,x + bcs fetchCode_nextBit +; clc + adc nBitCode_controlCount,x + bcs fetchCode_control +; clc + adc nBitCode_literalOffset,x + tax + lda codeToLiteralSymbol,x + clc + rts +fetchCode_control: +; sec + adc nBitCode_controlOffset-1,x + tax + lda codeToControlSymbol-1,x + and #$1f ; make distance symbols zero-based + tax + sec rts -; -------------------------------------------------------------------------- -; Decode low byte of a value (length or distance), basing on the code in A. -; The result is the base value for this code plus some bits read from input. - -getValue: - tay - ldx lengthExtraBits-1,y - lda lengthBaseValue_l-1,y - pha - lda lengthBaseValue_h-1,y - tay - pla -; jmp getBits - -; -------------------------------------------------------------------------- -; Read X-bit number from the input and add it to A. -; Increment Y if overflow. -; If X > 8, read only 8 bits. -; On return X holds number of unread bits: X = (X > 8 ? X - 8 : 0); - +; Read A minus 1 bits, but no more than 8 +getAMinus1BitsMax8: + rol getBits_base + tax + cmp #9 + bcs getByte + lda getNPlus1Bits_mask-2,x getBits: - cpx #0 - beq getBits_ret -.if (.cpu & CPU_ISET_65SC02) - stz getBits_tmp - dec getBits_tmp -.else - pha - lda #$ff - sta getBits_tmp - pla -.endif -getBits_1: - jsr getBit - bcc getBits_2 - sbc getBits_tmp ; C flag is set - bcc getBits_2 - iny -getBits_2: - dex - beq getBits_ret - asl getBits_tmp - bmi getBits_1 -getBits_ret: + jsr getBits_loop +getBits_normalizeLoop: + lsr getBits_base + ror a + bcc getBits_normalizeLoop rts -; -------------------------------------------------------------------------- -; Read a single bit from input, return it in the C flag. +; Read 16 bits +getWord: + jsr getByte + tax +; Read 8 bits +getByte: + lda #$80 +getBits_loop: + jsr getBit + ror a + bcc getBits_loop + rts +; Read one bit, return in the C flag getBit: - lsr getBit_hold - bne getBit_ret + lsr getBit_buffer + bne getBit_return pha -.if (.cpu & CPU_ISET_65SC02) - lda (inputPointer) -.else - sty getBit_hold - ldy #0 +; ldy #0 lda (inputPointer),y - ldy getBit_hold -.endif inc inputPointer - bne getBit_1 + bne getBit_samePage inc inputPointer+1 -getBit_1: - ror a ; (C flag was set) - sta getBit_hold +getBit_samePage: + sec + ror a + sta getBit_buffer pla -getBit_ret: +getBit_return: + rts + +; Copy a previously written byte +copyByte: + ldy outputPointer + lda (inflateCodes_sourcePointer),y + ldy #0 +; Write a byte +storeByte: +; ldy #0 + sta (outputPointer),y + inc outputPointer + bne storeByte_return + inc outputPointer+1 + inc inflateCodes_sourcePointer+1 +storeByte_return: rts @@ -575,57 +487,17 @@ getBit_ret: ; .rodata -; -------------------------------------------------------------------------- -; Arrays for the temporary codes. - -; Order, in which lengths of the temporary codes are stored. -tempCodeLengthOrder: - .byte 16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15 -; Base values. -tempBaseValue: - .byte 3,3,11 +getNPlus1Bits_mask: + .byte GET_1_BIT,GET_2_BITS,GET_3_BITS,GET_4_BITS,GET_5_BITS,GET_6_BITS,GET_7_BITS -; Number of extra bits to read. -tempExtraBits: - .byte 2,3,7 +inflateDynamic_tempSymbols: + .byte GET_2_BITS,GET_3_BITS,GET_7_BITS,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15 -; -------------------------------------------------------------------------- -; Arrays for the length and distance codes. - -; Base values. -lengthBaseValue_l: - .byte <3,<4,<5,<6,<7,<8,<9,<10 - .byte <11,<13,<15,<17,<19,<23,<27,<31 - .byte <35,<43,<51,<59,<67,<83,<99,<115 - .byte <131,<163,<195,<227,<258 -distanceBaseValue_l: - .byte <1,<2,<3,<4,<5,<7,<9,<13 - .byte <17,<25,<33,<49,<65,<97,<129,<193 - .byte <257,<385,<513,<769,<1025,<1537,<2049,<3073 - .byte <4097,<6145,<8193,<12289,<16385,<24577 -lengthBaseValue_h: - .byte >3,>4,>5,>6,>7,>8,>9,>10 - .byte >11,>13,>15,>17,>19,>23,>27,>31 - .byte >35,>43,>51,>59,>67,>83,>99,>115 - .byte >131,>163,>195,>227,>258 -distanceBaseValue_h: - .byte >1,>2,>3,>4,>5,>7,>9,>13 - .byte >17,>25,>33,>49,>65,>97,>129,>193 - .byte >257,>385,>513,>769,>1025,>1537,>2049,>3073 - .byte >4097,>6145,>8193,>12289,>16385,>24577 - -; Number of extra bits to read. -lengthExtraBits: - .byte 0,0,0,0,0,0,0,0 - .byte 1,1,1,1,2,2,2,2 - .byte 3,3,3,3,4,4,4,4 - .byte 5,5,5,5,0 -distanceExtraBits: - .byte 0,0,0,0,1,1,2,2 - .byte 3,3,4,4,5,5,6,6 - .byte 7,7,8,8,9,9,10,10 - .byte 11,11,12,12,13,13 +inflateDynamic_headerBits: + .byte GET_4_BITS,GET_5_BITS,GET_5_BITS +inflateDynamic_headerBase: + .byte 3,LENGTH_SYMBOLS,0 ; -------------------------------------------------------------------------- @@ -635,46 +507,28 @@ distanceExtraBits: .bss -; Number of literal codes of each length in the primary tree -; (MAX_BITS bytes, overlap with literalCodeLength). -literalCount: - -; -------------------------------------------------------------------------- -; Data for building the primary tree. +; Data for building trees. -; Lengths of literal codes. -literalCodeLength: +literalSymbolCodeLength: .res 256 -; Length of the end code. -endCodeLength: - .res 1 -; Lengths of length codes. -lengthCodeLength: - .res 29 - -; -------------------------------------------------------------------------- -; Data for building the distance tree. - -; Lengths of distance codes. -distanceCodeLength: - .res 30 -; For two unused codes in the fixed trees and an 'end' mark. - .res 3 - -; -------------------------------------------------------------------------- -; The Huffman trees. - -; Number of codes of each length. -bitsCount: - .res TREES_SIZE -; Pointers to sorted codes of each length. -bitsPointer_l: - .res TREES_SIZE+1 -bitsPointer_h: - .res TREES_SIZE - -; Sorted codes. -sortedCodes: - .res 256+1+29+30+2 - -.endif +controlSymbolCodeLength: + .res CONTROL_SYMBOLS + +; Huffman trees. + +nBitCode_clearFrom: +nBitCode_totalCount: + .res 2*TREE_SIZE +nBitCode_literalCount: + .res TREE_SIZE +nBitCode_controlCount: + .res 2*TREE_SIZE +nBitCode_literalOffset: + .res TREE_SIZE +nBitCode_controlOffset: + .res 2*TREE_SIZE + +codeToLiteralSymbol: + .res 256 +codeToControlSymbol: + .res CONTROL_SYMBOLS -- 2.39.5