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/* Copyright (C) 1995, 1996, 1997, 1998, 1999 Aladdin Enterprises. All rights reserved.
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This software is provided AS-IS with no warranty, either express or
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implied.
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This software is distributed under license and may not be copied,
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modified or distributed except as expressly authorized under the terms
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of the license contained in the file LICENSE in this distribution.
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For more information about licensing, please refer to
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http://www.ghostscript.com/licensing/. For information on
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commercial licensing, go to http://www.artifex.com/licensing/ or
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contact Artifex Software, Inc., 101 Lucas Valley Road #110,
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San Rafael, CA 94903, U.S.A., +1(415)492-9861.
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*/
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/* $Id: gsbittab.c,v 1.5 2002/06/16 05:48:55 lpd Exp $ */
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/* Tables for bit operations */
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#include "stdpre.h"
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#include "gsbittab.h"
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/* ---------------- Byte processing tables ---------------- */
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/*
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* byte_reverse_bits[B] = the byte B with the order of bits reversed.
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*/
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const byte byte_reverse_bits[256] = {
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bit_table_8(0, 1, 2, 4, 8, 0x10, 0x20, 0x40, 0x80)
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};
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/*
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* byte_right_mask[N] = a byte with N trailing 1s, 0 <= N <= 8.
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*/
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const byte byte_right_mask[9] = {
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0, 1, 3, 7, 0xf, 0x1f, 0x3f, 0x7f, 0xff
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};
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/*
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* byte_count_bits[B] = the number of 1-bits in a byte with value B.
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*/
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const byte byte_count_bits[256] = {
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bit_table_8(0, 1, 1, 1, 1, 1, 1, 1, 1)
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};
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/* ---------------- Scanning tables ---------------- */
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/*
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* byte_bit_run_length_N[B], for 0 <= N <= 7, gives the length of the
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* run of 1-bits starting at bit N in a byte with value B,
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* numbering the bits in the byte as 01234567. If the run includes
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* the low-order bit (i.e., might be continued into a following byte),
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* the run length is increased by 8.
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*/
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#define t8(n) n,n,n,n,n+1,n+1,n+2,n+11
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#define r8(n) n,n,n,n,n,n,n,n
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#define r16(n) r8(n),r8(n)
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#define r32(n) r16(n),r16(n)
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#define r64(n) r32(n),r32(n)
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#define r128(n) r64(n),r64(n)
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const byte byte_bit_run_length_0[256] = {
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r128(0), r64(1), r32(2), r16(3), r8(4), t8(5)
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};
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const byte byte_bit_run_length_1[256] = {
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r64(0), r32(1), r16(2), r8(3), t8(4),
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r64(0), r32(1), r16(2), r8(3), t8(4)
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};
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const byte byte_bit_run_length_2[256] = {
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r32(0), r16(1), r8(2), t8(3),
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r32(0), r16(1), r8(2), t8(3),
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r32(0), r16(1), r8(2), t8(3),
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r32(0), r16(1), r8(2), t8(3)
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};
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const byte byte_bit_run_length_3[256] = {
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r16(0), r8(1), t8(2), r16(0), r8(1), t8(2),
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r16(0), r8(1), t8(2), r16(0), r8(1), t8(2),
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r16(0), r8(1), t8(2), r16(0), r8(1), t8(2),
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r16(0), r8(1), t8(2), r16(0), r8(1), t8(2)
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};
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const byte byte_bit_run_length_4[256] = {
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r8(0), t8(1), r8(0), t8(1), r8(0), t8(1), r8(0), t8(1),
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r8(0), t8(1), r8(0), t8(1), r8(0), t8(1), r8(0), t8(1),
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r8(0), t8(1), r8(0), t8(1), r8(0), t8(1), r8(0), t8(1),
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r8(0), t8(1), r8(0), t8(1), r8(0), t8(1), r8(0), t8(1),
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};
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#define rr8(a,b,c,d,e,f,g,h)\
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a,b,c,d,e,f,g,h, a,b,c,d,e,f,g,h, a,b,c,d,e,f,g,h, a,b,c,d,e,f,g,h,\
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a,b,c,d,e,f,g,h, a,b,c,d,e,f,g,h, a,b,c,d,e,f,g,h, a,b,c,d,e,f,g,h,\
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a,b,c,d,e,f,g,h, a,b,c,d,e,f,g,h, a,b,c,d,e,f,g,h, a,b,c,d,e,f,g,h,\
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a,b,c,d,e,f,g,h, a,b,c,d,e,f,g,h, a,b,c,d,e,f,g,h, a,b,c,d,e,f,g,h,\
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a,b,c,d,e,f,g,h, a,b,c,d,e,f,g,h, a,b,c,d,e,f,g,h, a,b,c,d,e,f,g,h,\
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a,b,c,d,e,f,g,h, a,b,c,d,e,f,g,h, a,b,c,d,e,f,g,h, a,b,c,d,e,f,g,h,\
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a,b,c,d,e,f,g,h, a,b,c,d,e,f,g,h, a,b,c,d,e,f,g,h, a,b,c,d,e,f,g,h,\
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a,b,c,d,e,f,g,h, a,b,c,d,e,f,g,h, a,b,c,d,e,f,g,h, a,b,c,d,e,f,g,h
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const byte byte_bit_run_length_5[256] = {
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rr8(0, 0, 0, 0, 1, 1, 2, 11)
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};
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const byte byte_bit_run_length_6[256] = {
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rr8(0, 0, 1, 10, 0, 0, 1, 10)
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};
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const byte byte_bit_run_length_7[256] = {
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rr8(0, 9, 0, 9, 0, 9, 0, 9)
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};
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/* Pointer tables indexed by bit number. */
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const byte *const byte_bit_run_length[8] = {
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byte_bit_run_length_0, byte_bit_run_length_1,
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byte_bit_run_length_2, byte_bit_run_length_3,
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byte_bit_run_length_4, byte_bit_run_length_5,
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byte_bit_run_length_6, byte_bit_run_length_7
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};
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const byte *const byte_bit_run_length_neg[8] = {
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byte_bit_run_length_0, byte_bit_run_length_7,
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byte_bit_run_length_6, byte_bit_run_length_5,
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byte_bit_run_length_4, byte_bit_run_length_3,
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byte_bit_run_length_2, byte_bit_run_length_1
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};
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/*
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* byte_acegbdfh_to_abcdefgh[acegbdfh] = abcdefgh, where the letters
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* denote the individual bits of the byte.
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*/
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const byte byte_acegbdfh_to_abcdefgh[256] = {
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bit_table_8(0, 0x80, 0x20, 0x08, 0x02, 0x40, 0x10, 0x04, 0x01)
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};
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/* Some C compilers insist on having executable code in every file.... */
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void gsbittab_dummy(void); /* for picky compilers */
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void
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gsbittab_dummy(void)
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{
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}
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