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// Copyright 2020 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/wasm/simd-shuffle.h"
#include <algorithm>
#include "src/common/globals.h"
namespace v8 {
namespace internal {
namespace wasm {
bool SimdShuffle::TryMatchIdentity(const uint8_t* shuffle) {
for (int i = 0; i < kSimd128Size; ++i) {
if (shuffle[i] != i) return false;
}
return true;
}
bool SimdShuffle::TryMatch32x4Rotate(const uint8_t* shuffle,
uint8_t* shuffle32x4, bool is_swizzle) {
uint8_t offset;
bool is_concat = TryMatchConcat(shuffle, &offset);
DCHECK_NE(offset, 0); // 0 is identity, it should not be matched.
// Since we already have a concat shuffle, we know that the indices goes from:
// [ offset, ..., 15, 0, ... ], it suffices to check that the offset points
// to the low byte of a 32x4 element.
if (!is_concat || !is_swizzle || offset % 4 != 0) {
return false;
}
uint8_t offset_32 = offset / 4;
for (int i = 0; i < 4; i++) {
shuffle32x4[i] = (offset_32 + i) % 4;
}
return true;
}
bool SimdShuffle::TryMatch32x4Shuffle(const uint8_t* shuffle,
uint8_t* shuffle32x4) {
for (int i = 0; i < 4; ++i) {
if (shuffle[i * 4] % 4 != 0) return false;
for (int j = 1; j < 4; ++j) {
if (shuffle[i * 4 + j] - shuffle[i * 4 + j - 1] != 1) return false;
}
shuffle32x4[i] = shuffle[i * 4] / 4;
}
return true;
}
bool SimdShuffle::TryMatch32x8Shuffle(const uint8_t* shuffle,
uint8_t* shuffle32x8) {
for (int i = 0; i < 8; ++i) {
if (shuffle[i * 4] % 4 != 0) return false;
for (int j = 1; j < 4; ++j) {
if (shuffle[i * 4 + j] - shuffle[i * 4 + j - 1] != 1) return false;
}
shuffle32x8[i] = shuffle[i * 4] / 4;
}
return true;
}
bool SimdShuffle::TryMatch16x8Shuffle(const uint8_t* shuffle,
uint8_t* shuffle16x8) {
for (int i = 0; i < 8; ++i) {
if (shuffle[i * 2] % 2 != 0) return false;
for (int j = 1; j < 2; ++j) {
if (shuffle[i * 2 + j] - shuffle[i * 2 + j - 1] != 1) return false;
}
shuffle16x8[i] = shuffle[i * 2] / 2;
}
return true;
}
bool SimdShuffle::TryMatchConcat(const uint8_t* shuffle, uint8_t* offset) {
// Don't match the identity shuffle (e.g. [0 1 2 ... 15]).
uint8_t start = shuffle[0];
if (start == 0) return false;
DCHECK_GT(kSimd128Size, start); // The shuffle should be canonicalized.
// A concatenation is a series of consecutive indices, with at most one jump
// in the middle from the last lane to the first.
for (int i = 1; i < kSimd128Size; ++i) {
if ((shuffle[i]) != ((shuffle[i - 1] + 1))) {
if (shuffle[i - 1] != 15) return false;
if (shuffle[i] % kSimd128Size != 0) return false;
}
}
*offset = start;
return true;
}
bool SimdShuffle::TryMatchBlend(const uint8_t* shuffle) {
for (int i = 0; i < 16; ++i) {
if ((shuffle[i] & 0xF) != i) return false;
}
return true;
}
bool SimdShuffle::TryMatchByteToDwordZeroExtend(const uint8_t* shuffle) {
for (int i = 0; i < 16; ++i) {
if ((i % 4 != 0) && (shuffle[i] < 16)) return false;
if ((i % 4 == 0) && (shuffle[i] > 15 || (shuffle[i] != shuffle[0] + i / 4)))
return false;
}
return true;
}
uint8_t SimdShuffle::PackShuffle4(uint8_t* shuffle) {
return (shuffle[0] & 3) | ((shuffle[1] & 3) << 2) | ((shuffle[2] & 3) << 4) |
((shuffle[3] & 3) << 6);
}
uint8_t SimdShuffle::PackBlend8(const uint8_t* shuffle16x8) {
int8_t result = 0;
for (int i = 0; i < 8; ++i) {
result |= (shuffle16x8[i] >= 8 ? 1 : 0) << i;
}
return result;
}
uint8_t SimdShuffle::PackBlend4(const uint8_t* shuffle32x4) {
int8_t result = 0;
for (int i = 0; i < 4; ++i) {
result |= (shuffle32x4[i] >= 4 ? 0x3 : 0) << (i * 2);
}
return result;
}
int32_t SimdShuffle::Pack4Lanes(const uint8_t* shuffle) {
int32_t result = 0;
for (int i = 3; i >= 0; --i) {
result <<= 8;
result |= shuffle[i];
}
return result;
}
void SimdShuffle::Pack16Lanes(uint32_t* dst, const uint8_t* shuffle) {
for (int i = 0; i < 4; i++) {
dst[i] = wasm::SimdShuffle::Pack4Lanes(shuffle + (i * 4));
}
}
bool SimdSwizzle::AllInRangeOrTopBitSet(
std::array<uint8_t, kSimd128Size> shuffle) {
return std::all_of(shuffle.begin(), shuffle.end(),
[](auto i) { return (i < kSimd128Size) || (i & 0x80); });
}
} // namespace wasm
} // namespace internal
} // namespace v8
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