/**
* \file dnn/src/cuda/tqt/kern.cuh
* MegEngine is Licensed under the Apache License, Version 2.0 (the "License")
*
* Copyright (c) 2014-2021 Megvii Inc. All rights reserved.
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT ARRANTIES OR CONDITIONS OF ANY KIND, either express or
* implied.
*/
#pragma once
#include "src/cuda/elemwise_helper.cuh"
#include "src/cuda/utils.cuh"
#if MEGDNN_CC_HOST
#include "megdnn/oprs.h"
#endif
namespace megdnn {
namespace cuda {
template <typename ctype>
struct TQTKernOp {
ctype* input;
ctype* output;
ctype qmin, qmax;
__device__ void operator()(uint32_t idx, ctype scale) {
ctype t = powf(2, scale);
ctype x = round(input[idx] / t);
x = fmaxf(fminf(x, qmax), qmin);
output[idx] = x * t;
}
#if MEGDNN_CC_HOST
TQTKernOp(const TensorND& input, const TensorND& output, const TQT::Param& param)
: input{input.ptr<ctype>()},
output{output.ptr<ctype>()},
qmin(param.qmin),
qmax(param.qmax) {}
#endif
};
template <typename ctype>
struct TQTBwdKernOp {
ctype* diff;
ctype* input;
ctype* grad_x;
ctype* grad_s;
ctype qmin, qmax;
__device__ void operator()(uint32_t idx, ctype scale) {
ctype t = powf(2, scale);
ctype scaled = input[idx] / t;
ctype rounded = round(scaled);
rounded = fmaxf(fminf(rounded, qmax), qmin);
bool mask_clip = (scaled < -0.5 + qmin) + (scaled > 0.5 + qmax);
bool mask_quant = !mask_clip;
grad_x[idx] = diff[idx] * mask_quant;
ctype grad_quant = diff[idx] * mask_quant * (rounded - scaled) * t * log(2.0);
ctype grad_clip = diff[idx] * mask_clip * rounded * t * log(2.0);
grad_s[idx] = grad_quant + grad_clip;
}
#if MEGDNN_CC_HOST
TQTBwdKernOp(
const TensorND& diff, const TensorND& input, const TensorND& grad_x,
const TensorND& grad_s, const TQT::Param& param)
: diff{diff.ptr<ctype>()},
input{input.ptr<ctype>()},
grad_x{grad_x.ptr<ctype>()},
grad_s{grad_s.ptr<ctype>()},
qmin(param.qmin),
qmax(param.qmax) {}
#endif
};
template <typename ctype>
struct TQTKernOpNonContig {
ctype qmin;
ctype qmax;
__device__ void operator()(uint32_t, ctype& input, ctype& scale, ctype& output) {
ctype t = powf(2, scale);
ctype x = round(input / t);
x = fmaxf(fminf(x, qmax), qmin);
output = x * t;
}
#if MEGDNN_CC_HOST
TQTKernOpNonContig(const TQT::Param& param) : qmin(param.qmin), qmax(param.qmax) {}
#endif
};
template <typename ctype>
struct TQTBwdKernOpNonContig {
ctype qmin;
ctype qmax;
__device__ void operator()(
uint32_t, ctype& diff, ctype& input, ctype& scale, ctype& grad_x,
ctype& grad_s) {
ctype t = powf(2, scale);
ctype scaled = input / t;
ctype rounded = round(scaled);
rounded = fmaxf(fminf(rounded, qmax), qmin);
bool mask_clip = scaled < -0.5 + qmin && scaled > 0.5 + qmax;
bool mask_quant = !mask_clip;
grad_x = diff * mask_quant;
ctype grad_quant = diff * mask_quant * (rounded - scaled) * t * log(2.0);
ctype grad_clip = diff * mask_clip * rounded * t * log(2.0);
grad_s = grad_quant + grad_clip;
}
#if MEGDNN_CC_HOST
TQTBwdKernOpNonContig(const TQT::Param& param)
: qmin(param.qmin), qmax(param.qmax) {}
#endif
};
} // namespace cuda
} // namespace megdnn