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/* 
 * Copyright (c) 2015-2017, Intel Corporation
 * 
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions are met: 
 * 
 *  * Redistributions of source code must retain the above copyright notice, 
 *    this list of conditions and the following disclaimer. 
 *  * Redistributions in binary form must reproduce the above copyright 
 *    notice, this list of conditions and the following disclaimer in the 
 *    documentation and/or other materials provided with the distribution. 
 *  * Neither the name of Intel Corporation nor the names of its contributors 
 *    may be used to endorse or promote products derived from this software 
 *    without specific prior written permission. 
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
 * POSSIBILITY OF SUCH DAMAGE. 
 */ 
 
/** \file 
 * \brief Truffle compiler 
 * 
 * truffle is always able to represent an entire character class, providing a 
 * backstop to other acceleration engines. 
 */ 

#include "trufflecompile.h" 

#include "ue2common.h" 
#include "util/charreach.h" 
#include "util/dump_mask.h"
#include "util/simd_types.h" 
 
#include <cstring>

using namespace std; 
 
namespace ue2 { 
 
/* 
 * To represent an entire charclass (256 chars), truffle uses two 128 bit 
 * masks - the first is for chars that do not have the high bit/bit 7 set, 
 * i.e. chars {0..127}. The second mask is for chars with bit 7 set. 
 * 
 * Each char to be represented is split into the low nibble (bits {0..3}) and 
 * bits {4,5,6} - the low nibble is the offset into the mask and the value of 
 * bits 456 is the bit that is set at that offset. 
 */ 
 
void truffleBuildMasks(const CharReach &cr, u8 *shuf_mask_lo_highclear,
                       u8 *shuf_mask_lo_highset) {
    memset(shuf_mask_lo_highset, 0, sizeof(m128));
    memset(shuf_mask_lo_highclear, 0, sizeof(m128));
 
    for (size_t v = cr.find_first(); v != CharReach::npos; 
         v = cr.find_next(v)) { 
        DEBUG_PRINTF("adding 0x%02x to %s\n", (u8)v, (v & 0x80) ? "highset" : "highclear"); 
        u8 *change_mask = (v & 0x80) ? shuf_mask_lo_highset : shuf_mask_lo_highclear;
        u8 low_nibble = v & 0xf; 
        u8 bits_456 = (v & 0x70) >> 4; 
        change_mask[low_nibble] |= 1 << bits_456; 
    } 
} 
 
/* 
 * Reconstruct the charclass that the truffle masks represent 
 */ 
CharReach truffle2cr(const u8 *highclear, const u8 *highset) {
    CharReach cr; 
    for (u8 i = 0; i < 16; i++) { 
        u32 bits_456 = highclear[i];
        while (bits_456) { 
            u32 pos = findAndClearLSB_32(&bits_456); 
            assert(pos < 8); 
            cr.set(pos << 4 | i); 
        } 
        bits_456 = highset[i];
        while (bits_456) { 
            u32 pos = findAndClearLSB_32(&bits_456); 
            assert(pos < 8); 
            cr.set(0x80 | pos << 4 | i); 
        } 
    } 
    return cr; 
} 
 
} // namespc