Introduce Comper-X compression format and toolset.

CMakeLists.txt

@@ -305,6 +305,7 @@ endfunction()
 
 define_lib(artc42   "src/lib/artc42.cc"   "include/mdcomp/artc42.hh")
 define_lib(comper   "src/lib/comper.cc"   "include/mdcomp/comper.hh")
+define_lib(comperx  "src/lib/comperx.cc"  "include/mdcomp/comperx.hh")
 define_lib(enigma   "src/lib/enigma.cc"   "include/mdcomp/enigma.hh")
 define_lib(kosinski "src/lib/kosinski.cc" "include/mdcomp/kosinski.hh")
 define_lib(kosplus  "src/lib/kosplus.cc"  "include/mdcomp/kosplus.hh")
@@ -315,6 +316,7 @@ define_lib(saxman   "src/lib/saxman.cc"   "include/mdcomp/saxman.hh")
 define_lib(snkrle   "src/lib/snkrle.cc"   "include/mdcomp/snkrle.hh")
 
 define_exe(compercmp   "src/tools/compcmp.cc"  comper   compcmp)
+define_exe(comperxcmp  "src/tools/comperx.cc"  comperx  comperx)
 define_exe(enigmacmp   "src/tools/enicmp.cc"   enigma   enicmp)
 define_exe(kosinskicmp "src/tools/koscmp.cc"   kosinski koscmp)
 define_exe(kospluscmp  "src/tools/kosplus.cc"  kosplus  kosplus)
@@ -336,6 +338,7 @@ install(
         bigendian_io
         artc42
         comper
+        comperx
         enigma
         kosinski
         kosplus
@@ -345,6 +348,7 @@ install(
         saxman
         snkrle
         compercmp
+        comperxcmp
         enigmacmp
         kosinskicmp
         kospluscmp
@@ -372,6 +376,7 @@ export(
         bigendian_io
         artc42
         comper
+        comperx
         enigma
         kosinski
         kosplus

include/mdcomp/comperx.hh

@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) Flamewing 2013-2016 <[email protected]>
+ *
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef LIB_COMPERX_HH
+#define LIB_COMPERX_HH
+
+#include <mdcomp/basic_decoder.hh>
+#include <mdcomp/moduled_adaptor.hh>
+
+#include <iosfwd>
+
+class comperx;
+using basic_comperx   = BasicDecoder<comperx, PadMode::PadEven>;
+using moduled_comperx = ModuledAdaptor<comperx, 4096U, 1U>;
+
+class comperx : public basic_comperx, public moduled_comperx {
+    friend basic_comperx;
+    friend moduled_comperx;
+    static bool encode(std::ostream& Dst, uint8_t const* data, size_t Size);
+
+public:
+    using basic_comperx::encode;
+    static bool decode(std::istream& Src, std::iostream& Dst);
+};
+
+#endif    // LIB_COMPERX_HH

src/asm/ComperX.asm

@@ -0,0 +1,142 @@
+; -----------------------------------------------------------------------------
+; Comper-X a newer, much faster implementation of Comper compression
+;
+; (c) 2021, vladikcomper
+; -----------------------------------------------------------------------------
+; Permission to use, copy, modify, and/or distribute this software for any
+; purpose with or without fee is hereby granted.
+;
+; THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+; WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+; MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+; ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+; WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+; ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+; OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+; -----------------------------------------------------------------------------
+; INPUT:
+;		a0		- Source Offset
+;		a1		- Destination Offset
+; 
+; USES:
+;		d0-d4, a2
+; -----------------------------------------------------------------------------
+
+; -----------------------------------------------------------------------------
+; Copy device for RLE transfers
+;
+; This is located above the compressor for accesibility reasons.
+; -----------------------------------------------------------------------------
+
+		rts									; copy length = 0 stops decompression
+		rept 127
+			move.l	d4, (a1)+
+		endm
+ComperXDec_CopyDevice_RLE:
+		dbf 	d3, ComperXDec.fetch_flag	; if bits counter remains, parse the next word
+		;bra	ComperXDec.load_flags_field	; ... fall through ...
+
+; -----------------------------------------------------------------------------
+; Decompressor starts here ...
+; -----------------------------------------------------------------------------
+
+ComperXDec:
+		moveq	#-1, d1					; d1 is used for negative sign-extended displacement
+		moveq	#0, d2					; d2 is used as 8-bit index for copy jump tables
+
+.load_flags_field:
+		moveq	#16-1, d3				; d3 = description field bits counter
+		move.w	(a0)+, d0				; d0 = description field data
+
+.fetch_flag:
+		add.w	d0, d0					; roll description field
+		bcs.s	.flag					; if a flag issued, branch
+		move.w	(a0)+, (a1)+ 			; otherwise, do uncompressed data
+
+.flag_next:
+		dbf 	d3, .fetch_flag			; if bits counter remains, parse the next word
+		bra.s	.load_flags_field		; start a new block
+
+; -----------------------------------------------------------------------------
+.end	rts
+
+; -----------------------------------------------------------------------------
+.flag:	move.b	(a0)+, d1				; d1 = Displacement (words) (sign-extended)
+		beq.s	.copy_rle				; displacement value of 0 (-1) triggers RLE mode
+		move.b	(a0)+, d2				; d2 = Copy length field
+
+		add.w	d1, d1					; d1 = Displacement * 2 (sign-extended)
+		lea 	-2(a1,d1.w), a2			; a2 = Start copy address
+
+		moveq	#-1, d1					; restore the value of d1 now ...
+
+		add.b	d2, d2					; test MSB of copy length field ...
+		bcc.s	.copy_long_start		; if not set, then transfer is even words, branch ...
+		move.w	(a2)+, (a1)+			; otherwise, copy odd word before falling into longwords loop ...
+
+.copy_long_start:
+		jmp		ComperXDec_CopyDevice(pc,d2.w)	; d2 = 0..$FE
+
+; -----------------------------------------------------------------------------
+.copy_rle:
+		move.b	(a0)+, d1				; d1 = - $100 + Copy length
+
+		move.w	-(a1), d4
+		swap	d4
+		move.w	(a1)+, d4				; d4 = data to copy
+
+		add.b	d1, d1					; test MSB of copy length field ...
+		bcc.s	.copy_long_rle_start	; if not set, then transfer is even words, branch ...
+		move.w	d4, (a1)+				; otherwise, copy odd word before falling into longwords loop ...
+
+.copy_long_rle_start:
+		jmp		ComperXDec_CopyDevice_RLE(pc,d1.w) ; d1 = -$100..-2
+
+; -----------------------------------------------------------------------------
+; Copy device for RLE transfers
+;
+; This is located below the compressor for accesibility reasons.
+; -----------------------------------------------------------------------------
+
+ComperXDec_CopyDevice:
+		rts										; copy length = 0 stops decompression
+		rept 127
+			move.l	(a2)+, (a1)+
+		endm
+		dbf 	d3, ComperXDec.fetch_flag		; if bits counter remains, parse the next word
+		bra		ComperXDec.load_flags_field
+
+; =============================================================================
+
+
+
+
+
+
+
+
+
+; =============================================================================
+; -----------------------------------------------------------------------------
+; Subroutine to decompress Moduled Comper-X
+; -----------------------------------------------------------------------------
+; INPUT:
+;		a0		- Source Offset
+;		a1		- Destination buffer
+; -----------------------------------------------------------------------------
+
+ComperXMDec:
+		lea		ComperXDec(pc), a3
+
+		move.w	(a0)+, d0
+		subq.w	#1, d0						; this is a trick to reduce number of blocks by one if size is modulo $1000
+		rol.w	#5, d0
+		and.w	#$1E, d0					; d0 = Number of blocks to decompress * 2 (0..1E)
+		neg.w	d0
+		jmp		.decompress_device(pc,d0)
+
+		rept 16-1
+			jsr		(a3)
+		endm
+.decompress_device:
+		jmp		(a3)