/*
 * Copyright (c) 2015-2017, Intel Corporation
 * Copyright (c) 2020, 2021, VectorCamp PC
 * Copyright (c) 2021, Arm Limited
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
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 *    this list of conditions and the following disclaimer.
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 *    notice, this list of conditions and the following disclaimer in the
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 *    may be used to endorse or promote products derived from this software
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 */

/** \file
 * \brief Shufti: character class acceleration.
 *
 * Utilises the SSSE3 pshufb shuffle instruction
 */

#include "shufti.h"
#include "ue2common.h"
#include "util/arch.h"
#include "util/bitutils.h"

/** \brief Naive byte-by-byte implementation. */
static really_inline
const u8 *shuftiFwdSlow(const u8 *lo, const u8 *hi, const u8 *buf,
                        const u8 *buf_end) {
    DEBUG_PRINTF("buf %p end %p \n", buf, buf_end);
    for (; buf < buf_end; ++buf) {
        u8 c = *buf;
        if (lo[c & 0xf] & hi[c >> 4]) {
            break;
        }
    }
    return buf;
}

/** \brief Naive byte-by-byte implementation. */
static really_inline
const u8 *shuftiRevSlow(const u8 *lo, const u8 *hi, const u8 *buf,
                        const u8 *buf_end) {
    for (buf_end--; buf_end >= buf; buf_end--) {
        u8 c = *buf_end;
        if (lo[c & 0xf] & hi[c >> 4]) {
            break;
        }
    }
    return buf_end;
}

#ifdef HAVE_SVE
#include "shufti_sve.hpp"
#else
#include "shufti_simd.hpp"
#endif