vectorscan/src/nfa/shufti.c
2016-03-01 11:21:39 +11:00

540 lines
17 KiB
C

/*
* Copyright (c) 2015, 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 Shufti: character class acceleration.
*
* Utilises the SSSE3 pshufb shuffle instruction
*/
#include "shufti.h"
#include "ue2common.h"
#include "util/bitutils.h"
#include "util/simd_utils.h"
#include "util/unaligned.h"
#include "shufti_common.h"
#include "util/simd_utils_ssse3.h"
/** \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) {
assert(buf < 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;
}
#if !defined(__AVX2__)
/* Normal SSSE3 shufti */
static really_inline
const u8 *firstMatch(const u8 *buf, u32 z) {
if (unlikely(z != 0xffff)) {
u32 pos = ctz32(~z & 0xffff);
assert(pos < 16);
return buf + pos;
} else {
return NULL; // no match
}
}
static really_inline
const u8 *fwdBlock(m128 mask_lo, m128 mask_hi, m128 chars, const u8 *buf,
const m128 low4bits, const m128 zeroes) {
u32 z = block(mask_lo, mask_hi, chars, low4bits, zeroes);
return firstMatch(buf, z);
}
const u8 *shuftiExec(m128 mask_lo, m128 mask_hi, const u8 *buf,
const u8 *buf_end) {
assert(buf && buf_end);
assert(buf < buf_end);
// Slow path for small cases.
if (buf_end - buf < 16) {
return shuftiFwdSlow((const u8 *)&mask_lo, (const u8 *)&mask_hi,
buf, buf_end);
}
const m128 zeroes = zeroes128();
const m128 low4bits = _mm_set1_epi8(0xf);
const u8 *rv;
size_t min = (size_t)buf % 16;
assert(buf_end - buf >= 16);
// Preconditioning: most of the time our buffer won't be aligned.
m128 chars = loadu128(buf);
rv = fwdBlock(mask_lo, mask_hi, chars, buf, low4bits, zeroes);
if (rv) {
return rv;
}
buf += (16 - min);
// Unrolling was here, but it wasn't doing anything but taking up space.
// Reroll FTW.
const u8 *last_block = buf_end - 16;
while (buf < last_block) {
m128 lchars = load128(buf);
rv = fwdBlock(mask_lo, mask_hi, lchars, buf, low4bits, zeroes);
if (rv) {
return rv;
}
buf += 16;
}
// Use an unaligned load to mop up the last 16 bytes and get an accurate
// picture to buf_end.
assert(buf <= buf_end && buf >= buf_end - 16);
chars = loadu128(buf_end - 16);
rv = fwdBlock(mask_lo, mask_hi, chars, buf_end - 16, low4bits, zeroes);
if (rv) {
return rv;
}
return buf_end;
}
static really_inline
const u8 *lastMatch(const u8 *buf, m128 t, m128 compare) {
#ifdef DEBUG
DEBUG_PRINTF("confirming match in:"); dumpMsk128(t); printf("\n");
#endif
u32 z = movemask128(eq128(t, compare));
if (unlikely(z != 0xffff)) {
u32 pos = clz32(~z & 0xffff);
DEBUG_PRINTF("buf=%p, pos=%u\n", buf, pos);
assert(pos >= 16 && pos < 32);
return buf + (31 - pos);
} else {
return NULL; // no match
}
}
static really_inline
const u8 *revBlock(m128 mask_lo, m128 mask_hi, m128 chars, const u8 *buf,
const m128 low4bits, const m128 zeroes) {
m128 c_lo = pshufb(mask_lo, GET_LO_4(chars));
m128 c_hi = pshufb(mask_hi, GET_HI_4(chars));
m128 t = and128(c_lo, c_hi);
#ifdef DEBUG
DEBUG_PRINTF(" chars: "); dumpMsk128AsChars(chars); printf("\n");
DEBUG_PRINTF(" char: "); dumpMsk128(chars); printf("\n");
DEBUG_PRINTF(" c_lo: "); dumpMsk128(c_lo); printf("\n");
DEBUG_PRINTF(" c_hi: "); dumpMsk128(c_hi); printf("\n");
DEBUG_PRINTF(" t: "); dumpMsk128(t); printf("\n");
#endif
return lastMatch(buf, t, zeroes);
}
const u8 *rshuftiExec(m128 mask_lo, m128 mask_hi, const u8 *buf,
const u8 *buf_end) {
assert(buf && buf_end);
assert(buf < buf_end);
// Slow path for small cases.
if (buf_end - buf < 16) {
return shuftiRevSlow((const u8 *)&mask_lo, (const u8 *)&mask_hi,
buf, buf_end);
}
const m128 zeroes = zeroes128();
const m128 low4bits = _mm_set1_epi8(0xf);
const u8 *rv;
assert(buf_end - buf >= 16);
// Preconditioning: most of the time our buffer won't be aligned.
m128 chars = loadu128(buf_end - 16);
rv = revBlock(mask_lo, mask_hi, chars, buf_end - 16, low4bits, zeroes);
if (rv) {
return rv;
}
buf_end = (const u8 *)((size_t)buf_end & ~((size_t)0xf));
// Unrolling was here, but it wasn't doing anything but taking up space.
// Reroll FTW.
const u8 *last_block = buf + 16;
while (buf_end > last_block) {
buf_end -= 16;
m128 lchars = load128(buf_end);
rv = revBlock(mask_lo, mask_hi, lchars, buf_end, low4bits, zeroes);
if (rv) {
return rv;
}
}
// Use an unaligned load to mop up the last 16 bytes and get an accurate
// picture to buf.
chars = loadu128(buf);
rv = revBlock(mask_lo, mask_hi, chars, buf, low4bits, zeroes);
if (rv) {
return rv;
}
return buf - 1;
}
static really_inline
const u8 *fwdBlock2(m128 mask1_lo, m128 mask1_hi, m128 mask2_lo, m128 mask2_hi,
m128 chars, const u8 *buf, const m128 low4bits,
const m128 ones) {
m128 chars_lo = GET_LO_4(chars);
m128 chars_hi = GET_HI_4(chars);
m128 c_lo = pshufb(mask1_lo, chars_lo);
m128 c_hi = pshufb(mask1_hi, chars_hi);
m128 t = or128(c_lo, c_hi);
#ifdef DEBUG
DEBUG_PRINTF(" chars: "); dumpMsk128AsChars(chars); printf("\n");
DEBUG_PRINTF(" char: "); dumpMsk128(chars); printf("\n");
DEBUG_PRINTF(" c_lo: "); dumpMsk128(c_lo); printf("\n");
DEBUG_PRINTF(" c_hi: "); dumpMsk128(c_hi); printf("\n");
DEBUG_PRINTF(" t: "); dumpMsk128(t); printf("\n");
#endif
m128 c2_lo = pshufb(mask2_lo, chars_lo);
m128 c2_hi = pshufb(mask2_hi, chars_hi);
m128 t2 = or128(t, shiftRight8Bits(or128(c2_lo, c2_hi)));
#ifdef DEBUG
DEBUG_PRINTF(" c2_lo: "); dumpMsk128(c2_lo); printf("\n");
DEBUG_PRINTF(" c2_hi: "); dumpMsk128(c2_hi); printf("\n");
DEBUG_PRINTF(" t2: "); dumpMsk128(t2); printf("\n");
#endif
u32 z = movemask128(eq128(t2, ones));
return firstMatch(buf, z);
}
const u8 *shuftiDoubleExec(m128 mask1_lo, m128 mask1_hi,
m128 mask2_lo, m128 mask2_hi,
const u8 *buf, const u8 *buf_end) {
const m128 ones = ones128();
const m128 low4bits = _mm_set1_epi8(0xf);
const u8 *rv;
size_t min = (size_t)buf % 16;
// Preconditioning: most of the time our buffer won't be aligned.
m128 chars = loadu128(buf);
rv = fwdBlock2(mask1_lo, mask1_hi, mask2_lo, mask2_hi,
chars, buf, low4bits, ones);
if (rv) {
return rv;
}
buf += (16 - min);
// Unrolling was here, but it wasn't doing anything but taking up space.
// Reroll FTW.
const u8 *last_block = buf_end - 16;
while (buf < last_block) {
m128 lchars = load128(buf);
rv = fwdBlock2(mask1_lo, mask1_hi, mask2_lo, mask2_hi,
lchars, buf, low4bits, ones);
if (rv) {
return rv;
}
buf += 16;
}
// Use an unaligned load to mop up the last 16 bytes and get an accurate
// picture to buf_end.
chars = loadu128(buf_end - 16);
rv = fwdBlock2(mask1_lo, mask1_hi, mask2_lo, mask2_hi,
chars, buf_end - 16, low4bits, ones);
if (rv) {
return rv;
}
return buf_end;
}
#else // AVX2 - 256 wide shuftis
static really_inline
const u8 *firstMatch(const u8 *buf, u32 z) {
if (unlikely(z != 0xffffffff)) {
u32 pos = ctz32(~z);
assert(pos < 32);
return buf + pos;
} else {
return NULL; // no match
}
}
static really_inline
const u8 *fwdBlock(m256 mask_lo, m256 mask_hi, m256 chars, const u8 *buf,
const m256 low4bits, const m256 zeroes) {
u32 z = block(mask_lo, mask_hi, chars, low4bits, zeroes);
return firstMatch(buf, z);
}
/* takes 128 bit masks, but operates on 256 bits of data */
const u8 *shuftiExec(m128 mask_lo, m128 mask_hi, const u8 *buf,
const u8 *buf_end) {
assert(buf && buf_end);
assert(buf < buf_end);
// Slow path for small cases.
if (buf_end - buf < 32) {
return shuftiFwdSlow((const u8 *)&mask_lo, (const u8 *)&mask_hi,
buf, buf_end);
}
const m256 zeroes = zeroes256();
const m256 low4bits = set32x8(0xf);
const m256 wide_mask_lo = set2x128(mask_lo);
const m256 wide_mask_hi = set2x128(mask_hi);
const u8 *rv;
size_t min = (size_t)buf % 32;
assert(buf_end - buf >= 32);
// Preconditioning: most of the time our buffer won't be aligned.
m256 chars = loadu256(buf);
rv = fwdBlock(wide_mask_lo, wide_mask_hi, chars, buf, low4bits, zeroes);
if (rv) {
return rv;
}
buf += (32 - min);
// Unrolling was here, but it wasn't doing anything but taking up space.
// Reroll FTW.
const u8 *last_block = buf_end - 32;
while (buf < last_block) {
m256 lchars = load256(buf);
rv = fwdBlock(wide_mask_lo, wide_mask_hi, lchars, buf, low4bits, zeroes);
if (rv) {
return rv;
}
buf += 32;
}
// Use an unaligned load to mop up the last 32 bytes and get an accurate
// picture to buf_end.
assert(buf <= buf_end && buf >= buf_end - 32);
chars = loadu256(buf_end - 32);
rv = fwdBlock(wide_mask_lo, wide_mask_hi, chars, buf_end - 32, low4bits, zeroes);
if (rv) {
return rv;
}
return buf_end;
}
static really_inline
const u8 *lastMatch(const u8 *buf, m256 t, m256 compare) {
#ifdef DEBUG
DEBUG_PRINTF("confirming match in:"); dumpMsk256(t); printf("\n");
#endif
u32 z = movemask256(eq256(t, compare));
if (unlikely(z != 0xffffffff)) {
u32 pos = clz32(~z);
DEBUG_PRINTF("buf=%p, pos=%u\n", buf, pos);
return buf + (31 - pos);
} else {
return NULL; // no match
}
}
static really_inline
const u8 *revBlock(m256 mask_lo, m256 mask_hi, m256 chars, const u8 *buf,
const m256 low4bits, const m256 zeroes) {
m256 c_lo = vpshufb(mask_lo, GET_LO_4(chars));
m256 c_hi = vpshufb(mask_hi, GET_HI_4(chars));
m256 t = and256(c_lo, c_hi);
#ifdef DEBUG
DEBUG_PRINTF(" chars: "); dumpMsk256AsChars(chars); printf("\n");
DEBUG_PRINTF(" char: "); dumpMsk256(chars); printf("\n");
DEBUG_PRINTF(" c_lo: "); dumpMsk256(c_lo); printf("\n");
DEBUG_PRINTF(" c_hi: "); dumpMsk256(c_hi); printf("\n");
DEBUG_PRINTF(" t: "); dumpMsk256(t); printf("\n");
#endif
return lastMatch(buf, t, zeroes);
}
/* takes 128 bit masks, but operates on 256 bits of data */
const u8 *rshuftiExec(m128 mask_lo, m128 mask_hi, const u8 *buf,
const u8 *buf_end) {
assert(buf && buf_end);
assert(buf < buf_end);
// Slow path for small cases.
if (buf_end - buf < 64) {
return shuftiRevSlow((const u8 *)&mask_lo, (const u8 *)&mask_hi,
buf, buf_end);
}
const m256 zeroes = zeroes256();
const m256 low4bits = set32x8(0xf);
const m256 wide_mask_lo = set2x128(mask_lo);
const m256 wide_mask_hi = set2x128(mask_hi);
const u8 *rv;
assert(buf_end - buf >= 32);
// Preconditioning: most of the time our buffer won't be aligned.
m256 chars = loadu256(buf_end - 32);
rv = revBlock(wide_mask_lo, wide_mask_hi, chars, buf_end - 32, low4bits, zeroes);
if (rv) {
return rv;
}
buf_end = (const u8 *)((size_t)buf_end & ~((size_t)0x1f));
// Unrolling was here, but it wasn't doing anything but taking up space.
// Reroll FTW.
const u8 *last_block = buf + 32;
while (buf_end > last_block) {
buf_end -= 32;
m256 lchars = load256(buf_end);
rv = revBlock(wide_mask_lo, wide_mask_hi, lchars, buf_end, low4bits, zeroes);
if (rv) {
return rv;
}
}
// Use an unaligned load to mop up the last 32 bytes and get an accurate
// picture to buf.
chars = loadu256(buf);
rv = revBlock(wide_mask_lo, wide_mask_hi, chars, buf, low4bits, zeroes);
if (rv) {
return rv;
}
return buf - 1;
}
static really_inline
const u8 *fwdBlock2(m256 mask1_lo, m256 mask1_hi, m256 mask2_lo, m256 mask2_hi,
m256 chars, const u8 *buf, const m256 low4bits,
const m256 ones) {
DEBUG_PRINTF("buf %p\n", buf);
m256 chars_lo = GET_LO_4(chars);
m256 chars_hi = GET_HI_4(chars);
m256 c_lo = vpshufb(mask1_lo, chars_lo);
m256 c_hi = vpshufb(mask1_hi, chars_hi);
m256 t = or256(c_lo, c_hi);
#ifdef DEBUG
DEBUG_PRINTF(" chars: "); dumpMsk256AsChars(chars); printf("\n");
DEBUG_PRINTF(" char: "); dumpMsk256(chars); printf("\n");
DEBUG_PRINTF(" c_lo: "); dumpMsk256(c_lo); printf("\n");
DEBUG_PRINTF(" c_hi: "); dumpMsk256(c_hi); printf("\n");
DEBUG_PRINTF(" t: "); dumpMsk256(t); printf("\n");
#endif
m256 c2_lo = vpshufb(mask2_lo, chars_lo);
m256 c2_hi = vpshufb(mask2_hi, chars_hi);
m256 t2 = or256(t, shift256Right8Bits(or256(c2_lo, c2_hi)));
#ifdef DEBUG
DEBUG_PRINTF(" c2_lo: "); dumpMsk256(c2_lo); printf("\n");
DEBUG_PRINTF(" c2_hi: "); dumpMsk256(c2_hi); printf("\n");
DEBUG_PRINTF(" t2: "); dumpMsk256(t2); printf("\n");
#endif
u32 z = movemask256(eq256(t2, ones));
return firstMatch(buf, z);
}
/* takes 128 bit masks, but operates on 256 bits of data */
const u8 *shuftiDoubleExec(m128 mask1_lo, m128 mask1_hi,
m128 mask2_lo, m128 mask2_hi,
const u8 *buf, const u8 *buf_end) {
if (buf_end - buf < 32) {
// not worth it
return buf;
}
const m256 ones = ones256();
const m256 low4bits = set32x8(0xf);
const m256 wide_mask1_lo = set2x128(mask1_lo);
const m256 wide_mask1_hi = set2x128(mask1_hi);
const m256 wide_mask2_lo = set2x128(mask2_lo);
const m256 wide_mask2_hi = set2x128(mask2_hi);
const u8 *rv;
size_t min = (size_t)buf % 32;
// Preconditioning: most of the time our buffer won't be aligned.
m256 chars = loadu256(buf);
rv = fwdBlock2(wide_mask1_lo, wide_mask1_hi, wide_mask2_lo, wide_mask2_hi,
chars, buf, low4bits, ones);
if (rv) {
return rv;
}
buf += (32 - min);
// Unrolling was here, but it wasn't doing anything but taking up space.
// Reroll FTW.
const u8 *last_block = buf_end - 32;
while (buf < last_block) {
m256 lchars = load256(buf);
rv = fwdBlock2(wide_mask1_lo, wide_mask1_hi, wide_mask2_lo, wide_mask2_hi,
lchars, buf, low4bits, ones);
if (rv) {
return rv;
}
buf += 32;
}
// Use an unaligned load to mop up the last 32 bytes and get an accurate
// picture to buf_end.
chars = loadu256(buf_end - 32);
rv = fwdBlock2(wide_mask1_lo, wide_mask1_hi, wide_mask2_lo, wide_mask2_hi,
chars, buf_end - 32, low4bits, ones);
if (rv) {
return rv;
}
return buf_end;
}
#endif //AVX2