Program Listing for File ApplySWAP.hpp¶
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// Copyright 2018-2023 Xanadu Quantum Technologies Inc.
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#pragma once
#include "AVXConceptType.hpp"
#include "AVXUtil.hpp"
#include "BitUtil.hpp"
#include "Blender.hpp"
#include "Permutation.hpp"
#include "Util.hpp"
#include <complex>
namespace Pennylane::LightningQubit::Gates::AVXCommon {
template <typename PrecisionT, std::size_t packed_size> struct ApplySWAP {
using Precision = PrecisionT;
using PrecisionAVXConcept =
typename AVXConcept<PrecisionT, packed_size>::Type;
constexpr static std::size_t packed_size_ = packed_size;
constexpr static bool symmetric = true;
template <size_t rev_wire0, std::size_t rev_wire1>
static consteval auto applyInternalInternalPermutation() {
const auto identity_perm = Permutation::identity<packed_size>();
std::array<uint8_t, packed_size> perm{};
for (size_t i = 0; i < packed_size / 2; i++) {
// swap rev_wire1 and rev_wire0 bits
const std::size_t b = ((i >> rev_wire0) ^ (i >> rev_wire1)) & 1U;
const std::size_t j = i ^ ((b << rev_wire0) | (b << rev_wire1));
perm[2 * i + 0] = identity_perm[2 * j + 0];
perm[2 * i + 1] = identity_perm[2 * j + 1];
}
return Permutation::compilePermutation<PrecisionT, packed_size>(perm);
}
template <size_t rev_wire0, std::size_t rev_wire1>
static void applyInternalInternal(std::complex<PrecisionT> *arr,
std::size_t num_qubits,
[[maybe_unused]] bool inverse) {
using namespace Permutation;
constexpr static auto perm =
applyInternalInternalPermutation<rev_wire0, rev_wire1>();
PL_LOOP_PARALLEL(1)
for (size_t n = 0; n < exp2(num_qubits); n += packed_size / 2) {
const auto v = PrecisionAVXConcept::load(arr + n);
PrecisionAVXConcept::store(arr + n, permute<perm>(v));
}
}
template <size_t min_rev_wire> static consteval auto createMask0() {
std::array<bool, packed_size> m{};
for (size_t i = 0; i < packed_size / 2; i++) {
if ((i & (1U << min_rev_wire)) != 0) {
m[2 * i + 0] = true;
m[2 * i + 1] = true;
} else {
m[2 * i + 0] = false;
m[2 * i + 1] = false;
}
}
return compileMask<PrecisionT, packed_size>(m);
}
template <size_t min_rev_wire> static consteval auto createMask1() {
std::array<bool, packed_size> m = {};
for (size_t i = 0; i < packed_size / 2; i++) {
if ((i & (1U << min_rev_wire)) != 0) {
m[2 * i + 0] = false;
m[2 * i + 1] = false;
} else {
m[2 * i + 0] = true;
m[2 * i + 1] = true;
}
}
return compileMask<PrecisionT, packed_size>(m);
}
template <size_t min_rev_wire>
static void applyInternalExternal(std::complex<PrecisionT> *arr,
std::size_t num_qubits,
std::size_t max_rev_wire,
[[maybe_unused]] bool inverse) {
using namespace Permutation;
const std::size_t max_rev_wire_shift =
(static_cast<std::size_t>(1U) << max_rev_wire);
const std::size_t max_wire_parity = fillTrailingOnes(max_rev_wire);
const std::size_t max_wire_parity_inv =
fillLeadingOnes(max_rev_wire + 1);
constexpr static auto compiled_mask0 = createMask0<min_rev_wire>();
constexpr static auto compiled_mask1 = createMask1<min_rev_wire>();
constexpr static auto compiled_perm = compilePermutation<PrecisionT>(
flip(identity<packed_size>(), min_rev_wire));
PL_LOOP_PARALLEL(1)
for (size_t k = 0; k < exp2(num_qubits - 1); k += packed_size / 2) {
const std::size_t i0 =
((k << 1U) & max_wire_parity_inv) | (max_wire_parity & k);
const std::size_t i1 = i0 | max_rev_wire_shift;
const auto v0 = PrecisionAVXConcept::load(arr + i0);
const auto v1 = PrecisionAVXConcept::load(arr + i1);
const auto w0 = maskPermute<compiled_perm, compiled_mask0>(v0, v1);
const auto w1 = maskPermute<compiled_perm, compiled_mask1>(v1, v0);
PrecisionAVXConcept::store(arr + i0, w0);
PrecisionAVXConcept::store(arr + i1, w1);
}
}
static void applyExternalExternal(std::complex<PrecisionT> *arr,
const std::size_t num_qubits,
const std::size_t rev_wire0,
const std::size_t rev_wire1,
[[maybe_unused]] bool inverse) {
const std::size_t rev_wire0_shift = static_cast<std::size_t>(1U)
<< rev_wire0;
const std::size_t rev_wire1_shift = static_cast<std::size_t>(1U)
<< rev_wire1;
const std::size_t rev_wire_min = std::min(rev_wire0, rev_wire1);
const std::size_t rev_wire_max = std::max(rev_wire0, rev_wire1);
const std::size_t parity_low = fillTrailingOnes(rev_wire_min);
const std::size_t parity_high = fillLeadingOnes(rev_wire_max + 1);
const std::size_t parity_middle =
fillLeadingOnes(rev_wire_min + 1) & fillTrailingOnes(rev_wire_max);
PL_LOOP_PARALLEL(1)
for (size_t k = 0; k < exp2(num_qubits - 2); k += packed_size / 2) {
const std::size_t i00 = ((k << 2U) & parity_high) |
((k << 1U) & parity_middle) |
(k & parity_low);
const std::size_t i01 = i00 | rev_wire0_shift;
const std::size_t i10 = i00 | rev_wire1_shift;
const auto v01 = PrecisionAVXConcept::load(arr + i01); // 01
const auto v10 = PrecisionAVXConcept::load(arr + i10); // 10
PrecisionAVXConcept::store(arr + i10, v01);
PrecisionAVXConcept::store(arr + i01, v10);
}
}
};
} // namespace Pennylane::LightningQubit::Gates::AVXCommon
api/program_listing_file_pennylane_lightning_core_src_simulators_lightning_qubit_gates_cpu_kernels_avx_common_ApplySWAP.hpp
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