From 9bcf1e97960c0da7322a868efdbc07e2650716fe Mon Sep 17 00:00:00 2001 From: "Juan J. Martinez" Date: Sat, 9 Jan 2021 09:01:05 +0000 Subject: Extra libs: ap.lib aPLib support with apultra. --- tools/apultra/asm/6809/unaplib_6309_b.s | 143 ++++++++++++++++++++++++++++++++ 1 file changed, 143 insertions(+) create mode 100644 tools/apultra/asm/6809/unaplib_6309_b.s (limited to 'tools/apultra/asm/6809/unaplib_6309_b.s') diff --git a/tools/apultra/asm/6809/unaplib_6309_b.s b/tools/apultra/asm/6809/unaplib_6309_b.s new file mode 100644 index 0000000..8343edf --- /dev/null +++ b/tools/apultra/asm/6809/unaplib_6309_b.s @@ -0,0 +1,143 @@ +; unaplib_6309_b.s - aPLib backward decompressor for H6309 - 139 bytes +; +; in: x = last byte of compressed data +; y = last byte of decompression buffer +; out: y = first byte of decompressed data +; +; Copyright (C) 2020 Emmanuel Marty +; +; This software is provided 'as-is', without any express or implied +; warranty. In no event will the authors be held liable for any damages +; arising from the use of this software. +; +; Permission is granted to anyone to use this software for any purpose, +; including commercial applications, and to alter it and redistribute it +; freely, subject to the following restrictions: +; +; 1. The origin of this software must not be misrepresented; you must not +; claim that you wrote the original software. If you use this software +; in a product, an acknowledgment in the product documentation would be +; appreciated but is not required. +; 2. Altered source versions must be plainly marked as such, and must not be +; misrepresented as being the original software. +; 3. This notice may not be removed or altered from any source distribution. + + +; Original M6809 version written by Emmanuel Marty with Hitachi 6309 enhancements +; added by Doug Masten. +; +; Main advantage of H6309 CPU is the "TFM" instruction which can copy one +; byte of memory in 3 clock cycles vs a traditional copy loop that takes +; 20 clock cycles. + +; Options: +; APLIB_VAR +; Define variable to point to a DP memory location for a memory space +; and speed optimization. +; ex. APLIB_VAR equ +; +; APLIB_LONG_OFFSET_DISABLE +; Defined variable to disable long offsets >= 32000 for a speed and space +; optimization. Only enable this if you know what you are doing. +; ex. APLIB_LONG_OFFSET_DISABLE equ 1 + + +; define options + ifdef APLIB_VAR +apbitbuf equ APLIB_VAR ; bit queue (use DP memory for mem & space optimization) + else +apbitbuf fcb 0 ; bit queue (DEFAULT - use extended memory) + endc + + +apl_decompress + lda #$80 ; initialize empty bit queue + sta apbitbuf ; plus bit to roll into carry + leau 1,x + leay 1,y + +apcplit ldb ,-u ; copy literal byte +apwtlit stb ,-y + + ldb #3 ; set 'follows literal' flag + +aptoken bsr apgetbit ; read 'literal or match' bit + bcc apcplit ; if 0: literal + + bsr apgetbit ; read '8+n bits or other type' bit + bcs apother ; if 11x: other type of match + + bsr apgamma2 ; 10: read gamma2-coded high offset bits + clra + subr d,w ; high offset bits == 2 when follows_literal == 3 ? + bcc apnorep ; if not, not a rep-match + + bsr apgamma2 ; read repmatch length + bra apgotlen ; go copy large match + +apnorep tfr f,a ; transfer high offset bits to A + ldb ,-u ; read low offset byte in B + tfr d,x ; save match offset + + bsr apgamma2 ; read match length + + ifndef APLIB_LONG_OFFSET_DISABLE + cmpx #$7D00 ; offset >= 32000 ? + bge apincby2 ; if so, increase match len by 2 + endc + cmpx #$0500 ; offset >= 1280 ? + bge apincby1 ; if so, increase match len by 1 + cmpx #$80 ; offset < 128 ? + bge apgotlen ; if so, increase match len by 2 +apincby2 incw +apincby1 incw + +apgotlen tfr y,d ; transfer dst to D + addr x,d ; put backreference start address in D (dst + offset) + decd + leay -1,y + tfm d-,y- ; copy matched bytes + leay 1,y + + ldb #2 ; clear 'follows literal' flag + bra aptoken + +apgamma2 ldw #1 ; init to 1 so it gets shifted to 2 below +loop@ bsr apgetbit ; read data bit + rolw ; shift into W + bsr apgetbit ; read continuation bit + bcs loop@ ; loop until a zero continuation bit is read + rts + +apdibits bsr apgetbit ; read bit + rolb ; push into B +apgetbit lsl apbitbuf ; shift bit queue, and high bit into carry + bne aprts ; queue not empty, bits remain + lda ,-u ; read 8 new bits + rola ; shift bit queue, and high bit into carry + sta apbitbuf ; save bit queue +aprts rts + +apshort clrb + bsr apdibits ; read 2 offset bits + rolb + bsr apdibits ; read 4 offset bits + rolb + beq apwtlit ; if zero, go write it + + decb ; we load below without predecrement, adjust here + ldb b,y ; load backreferenced byte from dst+offset + bra apwtlit ; go write it + +apother bsr apgetbit ; read '7+1 match or short literal' bit + bcs apshort ; if 111: 4 bit offset for 1-byte copy + + ldb ,-u ; read low bits of offset + length bit in B + beq aprts ; check for EOD and exit if so + clra ; clear high bits in A + lsrb ; shift offset in place, shift length bit into carry + tfr d,x ; save match offset + ldb #1 ; len in B will be 2*1+carry: + rolb ; shift length, and carry into B + tfr d,w + bra apgotlen ; go copy match -- cgit v1.2.3