vectorscan/src/nfagraph/ng_limex_accel.h
2016-04-20 13:34:56 +10:00

127 lines
4.5 KiB
C++

/*
* Copyright (c) 2015-2016, 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 NFA acceleration analysis code.
*/
#ifndef NG_LIMEX_ACCEL_H
#define NG_LIMEX_ACCEL_H
#include "ng_holder.h"
#include "ng_misc_opt.h"
#include "ue2common.h"
#include "nfa/accelcompile.h"
#include "util/charreach.h"
#include "util/order_check.h"
#include "util/ue2_containers.h"
#include <map>
#include <vector>
namespace ue2 {
/* compile time accel defs */
#define MAX_ACCEL_DEPTH 4
#define MAX_MERGED_ACCEL_STOPS 200
#define ACCEL_MAX_STOP_CHAR 24
#define ACCEL_MAX_FLOATING_STOP_CHAR 192 /* accelerating sds is important */
#define MULTIACCEL_MIN_LEN 3
#define MULTIACCEL_MAX_LEN_SSE 15
#define MULTIACCEL_MAX_LEN_AVX2 31
// forward-declaration of CompileContext
struct CompileContext;
void findAccelFriends(const NGHolder &g, NFAVertex v,
const std::map<NFAVertex, BoundedRepeatSummary> &br_cyclic,
u32 offset,
ue2::flat_set<NFAVertex> *friends);
struct DoubleAccelInfo {
DoubleAccelInfo() : offset(0) {}
u32 offset; //!< offset correction to apply
CharReach stop1; //!< single-byte accel stop literals
flat_set<std::pair<u8, u8>> stop2; //!< double-byte accel stop literals
};
DoubleAccelInfo findBestDoubleAccelInfo(const NGHolder &g, NFAVertex v);
struct AccelScheme {
AccelScheme(const CharReach &cr_in, u32 offset_in)
: cr(cr_in), offset(offset_in) {
assert(offset <= MAX_ACCEL_DEPTH);
}
AccelScheme() : cr(CharReach::dot()), offset(MAX_ACCEL_DEPTH + 1) {}
bool operator<(const AccelScheme &b) const {
const AccelScheme &a = *this;
// Don't use ORDER_CHECK as it will (stupidly) eval count() too many
// times.
const size_t a_count = cr.count(), b_count = b.cr.count();
if (a_count != b_count) {
return a_count < b_count;
}
/* TODO: give bonus if one is a 'caseless' character */
ORDER_CHECK(offset);
ORDER_CHECK(cr);
return false;
}
bool operator>(const AccelScheme &b) const {
return b < *this;
}
CharReach cr;
u32 offset;
};
NFAVertex get_sds_or_proxy(const NGHolder &g);
AccelScheme nfaFindAccel(const NGHolder &g, const std::vector<NFAVertex> &verts,
const std::vector<CharReach> &refined_cr,
const std::map<NFAVertex, BoundedRepeatSummary> &br_cyclic,
bool allow_wide);
/** \brief Check if vertex \a v is an accelerable state (for a limex NFA). */
bool nfaCheckAccel(const NGHolder &g, NFAVertex v,
const std::vector<CharReach> &refined_cr,
const std::map<NFAVertex, BoundedRepeatSummary> &br_cyclic,
AccelScheme *as, bool allow_wide);
/** \brief Check if vertex \a v is a multi accelerable state (for a limex NFA). */
MultibyteAccelInfo nfaCheckMultiAccel(const NGHolder &g,
const std::vector<NFAVertex> &verts,
const CompileContext &cc);
} // namespace ue2
#endif