From: Piotr Fusik <fox@scene.pl>
Date: Mon, 6 Nov 2017 18:46:26 +0000 (+0100)
Subject: Fix 256 codes of same length
X-Git-Tag: V2.17~79^2
X-Git-Url: https://git.sur5r.net/?a=commitdiff_plain;h=refs%2Fpull%2F513%2Fhead;p=cc65

Fix 256 codes of same length
---

diff --git a/libsrc/zlib/inflatemem.s b/libsrc/zlib/inflatemem.s
index 27802fbff..f49c5fc79 100644
--- a/libsrc/zlib/inflatemem.s
+++ b/libsrc/zlib/inflatemem.s
@@ -1,5 +1,5 @@
 ;
-; 2017-02-12, Piotr Fusik
+; 2017-11-06, Piotr Fusik
 ;
 ; unsigned __fastcall__ inflatemem (char* dest, const char* source);
 ;
@@ -103,7 +103,7 @@ inflate_blockLoop:
 ;       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
+        jsr     getWord         ; get the one's complement length
         sta     inflateStored_pageCounter
         bcs     inflateStored_firstByte ; jmp
 inflateStored_copyByte:
@@ -332,7 +332,7 @@ inflateDynamic_storeControl:
 ; Build Huffman trees basing on code lengths (in bits)
 ; stored in the *SymbolCodeLength arrays
 buildHuffmanTree:
-; Clear nBitCode_totalCount, nBitCode_literalCount, nBitCode_controlCount
+; Clear nBitCode_literalCount, nBitCode_controlCount
         tya
 ;       lda     #0
 buildHuffmanTree_clear:
@@ -344,22 +344,20 @@ buildHuffmanTree_clear:
 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
+        ldx     #$100-4*TREE_SIZE
 buildHuffmanTree_calculateOffsets:
-        sta     nBitCode_literalOffset+3*TREE_SIZE-$100,x
+        sta     nBitCode_literalOffset+4*TREE_SIZE-$100,x
         clc
-        adc     nBitCode_literalCount+3*TREE_SIZE-$100,x
+        adc     nBitCode_literalCount+4*TREE_SIZE-$100,x
         inx
         bne     buildHuffmanTree_calculateOffsets
 ; Put symbols in their place in the sorted array
@@ -397,26 +395,26 @@ fetchCode_nextBit:
         rol     a
         inx
         sec
-        sbc     nBitCode_totalCount,x
+        sbc     nBitCode_literalCount,x
+        bcc     fetchCode_literal
+;       sec
+        sbc     nBitCode_controlCount,x
         bcs     fetchCode_nextBit
 ;       clc
-        adc     nBitCode_controlCount,x
-        bcs     fetchCode_control
+        adc     nBitCode_controlOffset,x
+        tax
+        lda     codeToControlSymbol,x
+        and     #$1f    ; make distance symbols zero-based
+        tax
+;       sec
+        rts
+fetchCode_literal:
 ;       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
 
 ; Read A minus 1 bits, but no more than 8
 getAMinus1BitsMax8:
@@ -517,14 +515,12 @@ controlSymbolCodeLength:
 ; Huffman trees.
 
 nBitCode_clearFrom:
-nBitCode_totalCount:
-        .res    2*TREE_SIZE
 nBitCode_literalCount:
-        .res    TREE_SIZE
+        .res    2*TREE_SIZE
 nBitCode_controlCount:
         .res    2*TREE_SIZE
 nBitCode_literalOffset:
-        .res    TREE_SIZE
+        .res    2*TREE_SIZE
 nBitCode_controlOffset:
         .res    2*TREE_SIZE