Files
paddlepaddle--paddle/paddle/phi/kernels/impl/fft_grad_kernel_impl.h
T
2026-07-13 12:40:42 +08:00

122 lines
4.6 KiB
C++

// Copyright (c) 2022 PaddlePaddle Authors. All Rights Reserved.
//
// 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 "paddle/phi/kernels/fft_grad_kernel.h"
#include <string>
#include <vector>
#include "paddle/common/ddim.h"
#include "paddle/phi/common/data_type.h"
#include "paddle/phi/core/kernel_registry.h"
#include "paddle/phi/core/tensor_meta.h"
#include "paddle/phi/kernels/complex_kernel.h"
#include "paddle/phi/kernels/empty_kernel.h"
#include "paddle/phi/kernels/funcs/fft.h"
#include "paddle/phi/kernels/funcs/fft_fill_conj.h"
#include "paddle/phi/kernels/funcs/for_range.h"
#include "paddle/phi/kernels/pad_kernel.h"
namespace phi {
template <typename T, typename Context>
void FFTC2CGradKernel(const Context& dev_ctx,
const DenseTensor& out_grad,
const std::vector<int64_t>& axes,
const std::string& normalization,
bool forward,
DenseTensor* x_grad) {
dev_ctx.template Alloc<T>(x_grad);
if (x_grad && x_grad->numel() == 0) {
return;
}
auto norm_type = funcs::get_norm_from_string(normalization, forward);
funcs::FFTC2CFunctor<Context, T, T> fft_c2c_func;
fft_c2c_func(dev_ctx, out_grad, x_grad, axes, norm_type, !forward);
}
template <typename T, typename Context>
void FFTR2CGradKernel(const Context& dev_ctx,
const DenseTensor& x,
const DenseTensor& out_grad,
const std::vector<int64_t>& axes,
const std::string& normalization,
bool forward,
bool onesided,
DenseTensor* x_grad) {
using R = typename T::value_type;
DenseTensor complex_x_grad = EmptyLike<T>(dev_ctx, x);
dev_ctx.template Alloc<R>(x_grad);
if (x_grad && x_grad->numel() == 0) {
return;
}
auto norm_type = funcs::get_norm_from_string(normalization, forward);
funcs::FFTC2CFunctor<Context, T, T> fft_c2c_func;
if (!onesided) {
fft_c2c_func(dev_ctx, out_grad, &complex_x_grad, axes, norm_type, !forward);
} else {
DenseTensor full_dy;
DenseTensorMeta full_dy_meta(out_grad.type(), x_grad->dims());
full_dy.set_meta(full_dy_meta);
auto zero_length = static_cast<int>(full_dy.dims().at(axes.back()) -
out_grad.dims().at(axes.back()));
auto rank = out_grad.dims().size();
std::vector<int> pads(rank * 2, 0);
pads[axes.back() * 2 + 1] = zero_length;
PadKernel<T>(dev_ctx, out_grad, pads, static_cast<float>(0.0), &full_dy);
fft_c2c_func(dev_ctx, full_dy, &complex_x_grad, axes, norm_type, !forward);
}
RealKernel<T>(dev_ctx, complex_x_grad, x_grad);
}
template <typename T, typename Context>
void FFTC2RGradKernel(const Context& dev_ctx,
const DenseTensor& out_grad,
const std::vector<int64_t>& axes,
const std::string& normalization,
bool forward,
int64_t last_dim_size UNUSED,
DenseTensor* x_grad) {
using C = dtype::complex<T>;
dev_ctx.template Alloc<C>(x_grad);
if (x_grad && x_grad->numel() == 0) {
return;
}
auto norm_type = funcs::get_norm_from_string(normalization, forward);
funcs::FFTR2CFunctor<Context, T, C> fft_r2c_func;
fft_r2c_func(dev_ctx, out_grad, x_grad, axes, norm_type, !forward);
const int64_t double_length =
out_grad.dims()[axes.back()] - x_grad->dims()[axes.back()];
int64_t stride_to_last_axis = 1;
auto ddim = x_grad->dims();
for (int i = ddim.size() - 2; i >= axes.back(); --i) {
stride_to_last_axis *= ddim[i + 1];
}
int64_t stride_second_to_last_axis = stride_to_last_axis * ddim[axes.back()];
funcs::FFTFillConjGradFunctor<C> func(x_grad->data<C>(),
axes.back(),
stride_second_to_last_axis,
stride_to_last_axis,
double_length);
size_t limit = x_grad->numel();
funcs::ForRange<Context> for_range(dev_ctx, limit);
for_range(func);
}
} // namespace phi