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2026-07-13 13:18:33 +08:00

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C++

// Copyright (c) Microsoft Corporation.
// SPDX-License-Identifier: Apache-2.0
// DeepSpeed Team
#pragma once
#define NOMINMAX // Windows idiosyncrasy
// https://stackoverflow.com/questions/4913922/possible-problems-with-nominmax-on-visual-c
#include <stdio.h>
#include <torch/extension.h>
#include <cassert>
#include "simd.h"
#include <cmath>
typedef unsigned short ds_half_precision_t;
#define STEP(SPAN) \
void Step_##SPAN(float* _params, \
float* grads, \
float* _exp_avg, \
float* _exp_avg_sq, \
size_t _param_size, \
ds_half_precision_t* dev_param = nullptr, \
bool half_precision = false);
class Adam_Optimizer {
public:
Adam_Optimizer(float alpha = 1e-3,
float betta1 = 0.9,
float betta2 = 0.999,
float eps = 1e-8,
float weight_decay = 0,
bool adamw_mode = true)
: _alpha(alpha),
_betta1(betta1),
_betta2(betta2),
_eps(eps),
_weight_decay(weight_decay),
_betta1_t(1.0),
_betta2_t(1.0),
_step(0),
_adamw_mode(adamw_mode)
{
}
~Adam_Optimizer() {}
#if defined(__AVX512__) or defined(__AVX256__)
template <int span>
void Step_AVX(size_t* rounded_size,
float* _params,
float* grads,
float* _exp_avg,
float* _exp_avg_sq,
size_t param_size,
ds_half_precision_t* dev_param = nullptr,
bool half_precision = false);
#endif
STEP(1)
STEP(4)
STEP(8)
inline void IncrementStep(size_t step, float beta1, float beta2)
{
if (beta1 != _betta1 || beta2 != _betta2) {
_step = step;
_betta1 = beta1;
_betta2 = beta2;
_betta1_t = std::pow(_betta1, step);
_betta2_t = std::pow(_betta2, step);
} else {
if (step == _step + 1) { // first optimizer step increase
_step++;
_betta1_t *= _betta1;
_betta2_t *= _betta2;
} else if (step ==
_step) { // no need to update step; beta1_t and beta2_t already updated
return;
} else { // support step increase not equal to 1
_betta1_t = std::pow(_betta1, step);
_betta2_t = std::pow(_betta2, step);
_step = step;
}
}
}
inline void update_state(float lr, float epsilon, float weight_decay, bool bias_correction)
{
_alpha = lr;
_eps = epsilon;
_weight_decay = weight_decay;
_bias_correction1 = 1.0f;
_bias_correction2 = 1.0f;
if (bias_correction == 1) {
_bias_correction1 = 1 - _betta1_t;
_bias_correction2 = 1 / sqrt(1 - _betta2_t);
}
}
private:
float _alpha;
float _betta1;
float _betta2;
float _eps;
float _weight_decay;
float _betta1_t;
float _betta2_t;
size_t _step;
float _bias_correction1;
float _bias_correction2;
bool _adamw_mode;
};
#if defined(__AVX512__) or defined(__AVX256__)
template <int span>
void Adam_Optimizer::Step_AVX(size_t* rounded_size,
float* _params,
float* grads,
float* _exp_avg,
float* _exp_avg_sq,
size_t _param_size,
ds_half_precision_t* dev_params,
bool half_precision)
{
size_t new_rounded_size = 0;
int rshft = half_precision ? 1 : 0;
AVX_Data betta1_4;
betta1_4.data = SIMD_SET(_betta1);
AVX_Data betta2_4;
betta2_4.data = SIMD_SET(_betta2);
float betta1_minus1 = 1 - _betta1;
float betta2_minus1 = 1 - _betta2;
AVX_Data betta1_minus1_4;
betta1_minus1_4.data = SIMD_SET(betta1_minus1);
AVX_Data betta2_minus1_4;
betta2_minus1_4.data = SIMD_SET(betta2_minus1);
AVX_Data bias2_sqrt;
bias2_sqrt.data = SIMD_SET(_bias_correction2);
AVX_Data eps_4;
eps_4.data = SIMD_SET(_eps);
float step_size = -1 * _alpha / _bias_correction1;
AVX_Data step_size_4;
step_size_4.data = SIMD_SET(step_size);
float w_decay = -1 * _alpha * _weight_decay;
AVX_Data weight_decay4;
if (_weight_decay > 0)
weight_decay4.data = (_adamw_mode ? SIMD_SET(w_decay) : SIMD_SET(_weight_decay));
new_rounded_size = ROUND_DOWN(_param_size, SIMD_WIDTH * span);
for (size_t t = 0; t < new_rounded_size; t += TILE) {
size_t copy_size = TILE;
if ((t + TILE) > new_rounded_size) copy_size = new_rounded_size - t;
size_t offset = copy_size + t;
#pragma omp parallel for
for (size_t i = t; i < offset; i += SIMD_WIDTH * span) {
AVX_Data grad_4[span];
simd_load<span>(grad_4, grads + (i >> rshft), half_precision);
AVX_Data momentum_4[span];
simd_load<span>(momentum_4, _exp_avg + i, false);
AVX_Data variance_4[span];
simd_load<span>(variance_4, _exp_avg_sq + i, false);
AVX_Data param_4[span];
simd_load<span>(param_4, _params + (i >> rshft), half_precision);
if (_weight_decay > 0 && !_adamw_mode) {
simd_fma<span>(grad_4, param_4, weight_decay4, grad_4);
}
simd_mul<span>(momentum_4, momentum_4, betta1_4);
simd_fma<span>(momentum_4, grad_4, betta1_minus1_4, momentum_4);
simd_mul<span>(variance_4, variance_4, betta2_4);
simd_mul<span>(grad_4, grad_4, grad_4);
simd_fma<span>(variance_4, grad_4, betta2_minus1_4, variance_4);
simd_sqrt<span>(grad_4, variance_4);
simd_fma<span>(grad_4, grad_4, bias2_sqrt, eps_4);
simd_div<span>(grad_4, momentum_4, grad_4);
if (_weight_decay > 0 && _adamw_mode) {
simd_fma<span>(param_4, param_4, weight_decay4, param_4);
}
simd_fma<span>(param_4, grad_4, step_size_4, param_4);
simd_store<span>(_params + (i >> rshft), param_4, half_precision);
simd_store<span>(_exp_avg + i, momentum_4, false);
simd_store<span>(_exp_avg_sq + i, variance_4, false);
}
}
*rounded_size = new_rounded_size;
}
#endif
int create_adam_optimizer(int optimizer_id,
float alpha = 1e-3,
float betta1 = 0.9,
float betta2 = 0.999,
float eps = 1e-8,
float weight_decay = 0,
bool adamw_mode = true,
bool should_log = false);
int ds_adam_step(int optimizer_id,
size_t step,
float lr,
float beta1,
float beta2,
float epsilon,
float weight_decay,
bool bias_correction,
torch::Tensor& params,
torch::Tensor& grads,
torch::Tensor& exp_avg,
torch::Tensor& exp_avg_sq);
int ds_adam_step_plus_copy(int optimizer_id,
size_t step,
float lr,
float beta1,
float beta2,
float epsilon,
float weight_decay,
bool bias_correction,
torch::Tensor& params,
torch::Tensor& grads,
torch::Tensor& exp_avg,
torch::Tensor& exp_avg_sq,
torch::Tensor& gpu_params);
int destroy_adam_optimizer(int optimizer_id);