动态形状、稀疏计算等高级特性昇腾实战

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​一、动态形状处理深度指南

1.1 动态形状基础与配置

# dynamic_shape_basics.py
import mindspore as ms
import mindspore.nn as nn
import mindspore.ops as ops
import numpy as np
from typing import Tuple, Optional, Union

class DynamicShapeConfig:
    """动态形状配置管理器"""
  
    def __init__(self, 
                 enable_dynamic_shape: bool = True,
                 max_dynamic_memory: str = "80%",  # 最大动态形状内存
                 min_dynamic_memory: str = "2GB",   # 最小动态形状内存
                 enable_shape_cache: bool = True,
                 cache_capacity: int = 50,
                 enable_auto_padding: bool = True):
      
        self.enable_dynamic_shape = enable_dynamic_shape
        self.max_dynamic_memory = max_dynamic_memory
        self.min_dynamic_memory = min_dynamic_memory
        self.enable_shape_cache = enable_shape_cache
        self.cache_capacity = cache_capacity
        self.enable_auto_padding = enable_auto_padding
      
        # 动态形状策略
        self.strategies = {
            "padding": self._padding_strategy,
            "reshape": self._reshape_strategy,
            "slice": self._slice_strategy,
            "batch_aware": self._batch_aware_strategy
        }
      
        # 形状历史记录
        self.shape_history = {}
        self.cache_hits = 0
        self.cache_misses = 0
  
    def configure_context(self):
        """配置动态形状相关上下文"""
        if not self.enable_dynamic_shape:
            return
      
        # 设置昇腾动态形状配置
        ascend_config = {
            "dynamic_shape_enable": True,
            "dynamic_shape_mem_limit": self.max_dynamic_memory,
            "dynamic_shape_min_mem": self.min_dynamic_memory,
            "dynamic_shape_cache_enable": self.enable_shape_cache,
            "dynamic_shape_cache_capacity": self.cache_capacity,
            "dynamic_inputs_shape_range": {}  # 动态形状范围
        }
      
        # 设置MindSpore上下文
        ms.set_context(
            mode=ms.GRAPH_MODE,
            device_target="Ascend",
            ascend_config=ascend_config,
            enable_dynamic_shape=True,
            max_device_memory=self.max_dynamic_memory,
            graph_kernel_flags="--enable_dynamic_shape_fusion=True"
        )
      
        print(f"动态形状已启用,内存限制: {self.max_dynamic_memory}")
        if self.enable_shape_cache:
            print(f"形状缓存容量: {self.cache_capacity}")
  
    def set_dynamic_range(self, model, input_shapes_ranges):
        """
        设置动态形状范围
      
        Args:
            model: 模型实例
            input_shapes_ranges: 输入形状范围字典
                Example: {
                    'input1': [(None, 3, 224, 224),  # 动态batch
                               (32, 3, 224, 224),     # 最小batch
                               (256, 3, 224, 224)]    # 最大batch
                }
        """
        if not self.enable_dynamic_shape:
            return
      
        # 设置动态输入
        dynamic_inputs = []
        for name, shape_range in input_shapes_ranges.items():
            min_shape, opt_shape, max_shape = shape_range
          
            # 创建动态张量
            dynamic_tensor = ms.Tensor(
                shape=[s if s is not None else -1 for s in min_shape],
                dtype=ms.float32
            )
            dynamic_inputs.append(dynamic_tensor)
          
            # 记录形状范围
            self.shape_history[name] = {
                'min': min_shape,
                'opt': opt_shape,
                'max': max_shape,
                'current': None
            }
      
        # 编译模型时设置动态输入
        model.set_inputs(*dynamic_inputs)
      
        print(f"设置动态形状范围: {input_shapes_ranges}")
  
    def _padding_strategy(self, tensor, target_shape):
        """填充策略 - 处理可变长度"""
        current_shape = tensor.shape
        pad_widths = []
      
        for curr, target in zip(current_shape, target_shape):
            if curr < target:
                pad_widths.append((0, target - curr))
            else:
                pad_widths.append((0, 0))
      
        return ops.Pad(pad_widths)(tensor)
  
    def _reshape_strategy(self, tensor, target_shape):
        """重塑策略 - 重新排列数据"""
        # 确保总元素数不变
        current_elements = np.prod(tensor.shape)
        target_elements = np.prod(target_shape)
      
        if current_elements != target_elements:
            raise ValueError(f"元素数不匹配: {current_elements} != {target_elements}")
      
        return ops.Reshape()(tensor, target_shape)
  
    def _slice_strategy(self, tensor, target_shape):
        """切片策略 - 截断多余部分"""
        slices = []
        for curr, target in zip(tensor.shape, target_shape):
            if curr > target:
                slices.append(slice(0, target))
            else:
                slices.append(slice(None))
      
        return tensor[tuple(slices)]
  
    def _batch_aware_strategy(self, tensor, target_shape):
        """批处理感知策略 - 智能处理批维度"""
        # 分离批维度和特征维度
        batch_dim = 0
        batch_size = tensor.shape[batch_dim]
        target_batch = target_shape[batch_dim]
      
        if batch_size == target_batch:
            return tensor
      
        if batch_size < target_batch:
            # 需要填充
            return self._batch_padding(tensor, target_shape)
        else:
            # 需要切片
            return self._batch_slicing(tensor, target_shape)
  
    def _batch_padding(self, tensor, target_shape):
        """批维度填充"""
        pad_config = [(0, target_shape[0] - tensor.shape[0])]
        pad_config.extend([(0, 0)] * (len(tensor.shape) - 1))
      
        return ops.Pad(pad_config)(tensor)
  
    def _batch_slicing(self, tensor, target_shape):
        """批维度切片"""
        slices = [slice(0, target_shape[0])]
        slices.extend([slice(None)] * (len(tensor.shape) - 1))
      
        return tensor[tuple(slices)]
  
    def adapt_shape(self, tensor, target_shape, strategy="batch_aware"):
        """自适应形状调整"""
        if strategy not in self.strategies:
            raise ValueError(f"未知策略: {strategy}")
      
        # 检查是否已经匹配
        if tensor.shape == target_shape:
            return tensor
      
        # 应用策略
        adapted = self.strategies[strategy](tensor, target_shape)
      
        # 记录形状变化
        self._log_shape_adaptation(tensor.shape, target_shape, strategy)
      
        return adapted
  
    def _log_shape_adaptation(self, src_shape, dst_shape, strategy):
        """记录形状适配日志"""
        key = f"{src_shape}->{dst_shape}:{strategy}"
      
        if key in self.shape_history:
            self.shape_history[key]['count'] += 1
            self.cache_hits += 1
        else:
            self.shape_history[key] = {
                'count': 1,
                'strategy': strategy,
                'timestamp': time.time()
            }
            self.cache_misses += 1
      
        # 打印重要形状变化
        if src_shape[0] != dst_shape[0]:  # 批维度变化
            print(f"批维度变化: {src_shape[0]} -> {dst_shape[0]} "
                  f"(策略: {strategy})")

1.2 动态形状模型设计

# dynamic_shape_models.py
class DynamicConv2D(nn.Cell):
    """动态卷积层 - 支持可变输入尺寸"""
  
    def __init__(self, 
                 in_channels: int,
                 out_channels: int,
                 kernel_size: Union[int, Tuple[int, int]] = 3,
                 stride: Union[int, Tuple[int, int]] = 1,
                 padding: Union[int, Tuple[int, int]] = 0,
                 dilation: Union[int, Tuple[int, int]] = 1,
                 groups: int = 1,
                 dynamic_kernel: bool = False):
      
        super().__init__()
      
        # 基本卷积参数
        self.in_channels = in_channels
        self.out_channels = out_channels
        self.kernel_size = kernel_size if isinstance(kernel_size, tuple) else (kernel_size, kernel_size)
        self.stride = stride if isinstance(stride, tuple) else (stride, stride)
        self.padding = padding if isinstance(padding, tuple) else (padding, padding)
        self.dilation = dilation if isinstance(dilation, tuple) else (dilation, dilation)
        self.groups = groups
      
        # 动态特性
        self.dynamic_kernel = dynamic_kernel
        self.shape_adapter = DynamicShapeConfig()
      
        # 卷积核
        if dynamic_kernel:
            # 动态卷积核 - 可适应不同输入尺寸
            self.kernel_generator = self._create_kernel_generator()
            self.current_kernel = None
        else:
            # 固定卷积核
            self.conv = nn.Conv2d(
                in_channels, out_channels, kernel_size,
                stride=stride, pad_mode='pad', padding=padding,
                dilation=dilation, group=groups,
                has_bias=True,
                weight_init='HeUniform'
            )
  
    def _create_kernel_generator(self):
        """创建动态卷积核生成器"""
        class KernelGenerator(nn.Cell):
            def __init__(self, base_channels, base_kernel):
                super().__init__()
                self.base_weight = ms.Parameter(
                    ms.Tensor(
                        np.random.randn(*base_kernel) * 0.01,
                        dtype=ms.float32
                    )
                )
                self.scale_factors = nn.Dense(base_channels, base_channels)
          
            def construct(self, input_shape):
                # 根据输入形状调整卷积核
                _, _, h, w = input_shape
              
                # 计算缩放因子
                scale_h = h / 224  # 假设224是基准高度
                scale_w = w / 224  # 假设224是基准宽度
              
                # 调整卷积核
                # 这里简化为插值,实际可能需要更复杂的调整
                if scale_h != 1.0 or scale_w != 1.0:
                    # 使用双线性插值调整卷积核大小
                    weight = ops.ResizeBilinear(
                        size=(int(self.base_weight.shape[2] * scale_h),
                              int(self.base_weight.shape[3] * scale_w)),
                        align_corners=False
                    )(self.base_weight)
                else:
                    weight = self.base_weight
              
                return weight
      
        base_kernel = (self.out_channels, self.in_channels // self.groups,
                      self.kernel_size[0], self.kernel_size[1])
      
        return KernelGenerator(self.in_channels, base_kernel)
  
    def construct(self, x):
        """前向传播 - 动态形状处理"""
        batch_size, channels, height, width = x.shape
      
        # 动态调整卷积核(如果需要)
        if self.dynamic_kernel:
            # 生成适应当前形状的卷积核
            kernel = self.kernel_generator(x.shape)
          
            # 动态卷积
            output = self._dynamic_conv2d(x, kernel)
        else:
            # 标准卷积
            output = self.conv(x)
      
        # 动态调整输出形状(如果需要)
        output = self._adapt_output_shape(output, x.shape)
      
        return output
  
    def _dynamic_conv2d(self, x, weight):
        """动态卷积实现"""
        # 使用自定义卷积实现支持动态形状
        # 这里简化实现,实际可能需要更复杂的处理
      
        # 计算输出形状
        out_h = (x.shape[2] + 2 * self.padding[0] - 
                 self.dilation[0] * (weight.shape[2] - 1) - 1) // self.stride[0] + 1
        out_w = (x.shape[3] + 2 * self.padding[1] - 
                 self.dilation[1] * (weight.shape[3] - 1) - 1) // self.stride[1] + 1
      
        # 实现卷积(简化版)
        # 实际生产环境应使用优化实现
        output = ops.Conv2D(
            out_channel=self.out_channels,
            kernel_size=self.kernel_size,
            mode=1,
            pad_mode="pad",
            pad=self.padding,
            stride=self.stride,
            dilation=self.dilation,
            group=self.groups
        )(x, weight)
      
        return output
  
    def _adapt_output_shape(self, output, input_shape):
        """调整输出形状"""
        # 这里可以添加后处理逻辑
        # 例如:动态批归一化、动态激活等
      
        return output

class DynamicSequenceModel(nn.Cell):
    """动态序列模型 - 支持可变序列长度"""
  
    def __init__(self, 
                 input_dim: int,
                 hidden_dim: int,
                 num_layers: int = 2,
                 bidirectional: bool = True,
                 dynamic_length: bool = True):
      
        super().__init__()
      
        self.input_dim = input_dim
        self.hidden_dim = hidden_dim
        self.num_layers = num_layers
        self.bidirectional = bidirectional
        self.dynamic_length = dynamic_length
      
        # RNN层(支持动态序列长度)
        self.rnn = nn.LSTM(
            input_size=input_dim,
            hidden_size=hidden_dim,
            num_layers=num_layers,
            has_bias=True,
            bidirectional=bidirectional,
            dropout=0.0,
            batch_first=True
        )
      
        # 动态形状处理器
        self.shape_processor = DynamicSequenceProcessor(
            hidden_dim * (2 if bidirectional else 1)
        )
  
    def construct(self, x, seq_lengths=None):
        """
        前向传播
      
        Args:
            x: 输入张量 [batch, seq_len, features]
            seq_lengths: 每个序列的实际长度 [batch]
        """
        batch_size, seq_len, features = x.shape
      
        # 处理动态序列长度
        if self.dynamic_length and seq_lengths is not None:
            # 使用pack_padded_sequence处理变长序列
            x_packed = self._pack_sequences(x, seq_lengths)
          
            # RNN处理
            output_packed, (h_n, c_n) = self.rnn(x_packed)
          
            # 解包
            output, output_lengths = self._unpack_sequences(
                output_packed, seq_lengths, batch_size, seq_len
            )
        else:
            # 固定长度处理
            output, (h_n, c_n) = self.rnn(x)
            output_lengths = None
      
        # 动态后处理
        output = self.shape_processor(output, seq_lengths)
      
        return output, h_n
  
    def _pack_sequences(self, x, lengths):
        """打包变长序列"""
        # 按长度降序排序
        sorted_lengths, sorted_indices = ops.Sort(descending=True)(lengths)
        sorted_x = x[sorted_indices]
      
        # 打包序列
        packed = nn.PackSequence(sorted_x, sorted_lengths)
      
        return packed
  
    def _unpack_sequences(self, packed_output, lengths, batch_size, max_len):
        """解包序列"""
        # 恢复原始顺序
        _, original_indices = ops.Sort()(lengths)
        original_indices = ops.Argsort()(original_indices)
      
        # 解包
        output, output_lengths = nn.UnpackSequence(packed_output, batch_size, max_len)
      
        # 恢复原始顺序
        output = output[original_indices]
      
        return output, output_lengths

class DynamicSequenceProcessor(nn.Cell):
    """动态序列处理器"""
  
    def __init__(self, hidden_dim):
        super().__init__()
      
        # 动态注意力机制
        self.attention = DynamicAttention(hidden_dim)
      
        # 动态层归一化
        self.layer_norm = DynamicLayerNorm(hidden_dim)
      
        # 动态dropout
        self.dropout = nn.Dropout(keep_prob=0.9)
  
    def construct(self, x, lengths=None):
        """处理序列"""
        # 动态掩码(如果提供了长度)
        if lengths is not None:
            mask = self._create_mask(x.shape[:2], lengths)
            x = x * mask.unsqueeze(-1)
      
        # 动态注意力
        x = self.attention(x, mask if lengths is not None else None)
      
        # 动态层归一化
        x = self.layer_norm(x)
      
        # dropout
        x = self.dropout(x)
      
        return x
  
    def _create_mask(self, shape, lengths):
        """创建序列掩码"""
        batch_size, max_len = shape
      
        # 创建范围张量
        range_tensor = ops.arange(max_len).broadcast_to((batch_size, max_len))
      
        # 创建掩码
        lengths_expanded = lengths.view(-1, 1)
        mask = range_tensor < lengths_expanded
      
        return mask.astype(ms.float32)

1.3 动态形状训练循环

# dynamic_training.py
class DynamicShapeTrainingLoop:
    """动态形状训练循环"""
  
    def __init__(self, 
                 model: nn.Cell,
                 optimizer: nn.Optimizer,
                 loss_fn: nn.Cell,
                 dynamic_config: DynamicShapeConfig,
                 enable_gradient_accumulation: bool = True,
                 accumulation_steps: int = 4):
      
        self.model = model
        self.optimizer = optimizer
        self.loss_fn = loss_fn
        self.dynamic_config = dynamic_config
        self.enable_gradient_accumulation = enable_gradient_accumulation
        self.accumulation_steps = accumulation_steps
      
        # 梯度累积
        self.accumulated_gradients = None
        self.accumulation_counter = 0
      
        # 形状统计
        self.shape_statistics = {
            'batch_sizes': [],
            'sequence_lengths': [],
            'image_sizes': []
        }
      
        # 性能监控
        self.recompilation_count = 0
        self.cache_hit_rate = 0.0
  
    def train_step(self, data, labels, sample_info=None):
        """动态形状训练步骤"""
      
        # 记录输入形状
        self._record_input_shapes(data, sample_info)
      
        # 动态调整模型(如果需要)
        if self._needs_recompilation(data.shape):
            self._recompile_model(data.shape)
      
        # 前向传播
        outputs = self.model(data)
      
        # 计算损失
        loss = self.loss_fn(outputs, labels)
      
        # 反向传播
        grads = self._compute_gradients(loss)
      
        # 梯度累积
        if self.enable_gradient_accumulation:
            grads = self._accumulate_gradients(grads)
      
        # 优化器步骤
        if not self.enable_gradient_accumulation or self.accumulation_counter == self.accumulation_steps:
            self.optimizer(grads)
            self._reset_accumulation()
      
        return loss, outputs
  
    def _record_input_shapes(self, data, sample_info):
        """记录输入形状统计"""
        shape = data.shape
      
        # 记录批大小
        self.shape_statistics['batch_sizes'].append(shape[0])
      
        # 记录序列长度或图像尺寸
        if len(shape) == 4:  # 图像 [B, C, H, W]
            self.shape_statistics['image_sizes'].append((shape[2], shape[3]))
        elif len(shape) == 3:  # 序列 [B, T, F]
            self.shape_statistics['sequence_lengths'].append(shape[1])
      
        # 限制历史大小
        for key in self.shape_statistics:
            if len(self.shape_statistics[key]) > 1000:
                self.shape_statistics[key] = self.shape_statistics[key][-500:]
  
    def _needs_recompilation(self, new_shape):
        """检查是否需要重新编译"""
        if not hasattr(self.model, 'last_compiled_shape'):
            return True
      
        last_shape = self.model.last_compiled_shape
      
        # 检查批维度变化
        if new_shape[0] != last_shape[0]:
            return True
      
        # 检查序列长度变化(对于序列模型)
        if len(new_shape) >= 3 and new_shape[1] != last_shape[1]:
            return True
      
        # 检查图像尺寸变化(对于视觉模型)
        if len(new_shape) == 4 and (new_shape[2] != last_shape[2] or 
                                    new_shape[3] != last_shape[3]):
            return True
      
        return False
  
    def _recompile_model(self, new_shape):
        """重新编译模型以适应新形状"""
        print(f"重新编译模型以适应形状: {new_shape}")
      
        # 设置动态输入
        dynamic_input = ms.Tensor(shape=new_shape, dtype=ms.float32)
        self.model.set_inputs(dynamic_input)
      
        # 编译模型
        self.model.compile()
      
        # 记录编译形状
        self.model.last_compiled_shape = new_shape
      
        # 更新统计
        self.recompilation_count += 1
  
    def _compute_gradients(self, loss):
        """计算梯度"""
        # 使用MindSpore的自动微分
        grads = ms.grad(self._forward_and_loss, None, self.optimizer.parameters)(loss)
        return grads
  
    def _forward_and_loss(self, data, labels):
        """前向传播和损失计算"""
        outputs = self.model(data)
        loss = self.loss_fn(outputs, labels)
        return loss
  
    def _accumulate_gradients(self, grads):
        """梯度累积"""
        if self.accumulated_gradients is None:
            self.accumulated_gradients = [
                ms.ops.zeros_like(g) if g is not None else None 
                for g in grads
            ]
      
        # 累积梯度
        for i, grad in enumerate(grads):
            if grad is not None and self.accumulated_gradients[i] is not None:
                self.accumulated_gradients[i] += grad / self.accumulation_steps
      
        self.accumulation_counter += 1
      
        return self.accumulated_gradients if self.accumulation_counter == self.accumulation_steps else None
  
    def _reset_accumulation(self):
        """重置梯度累积"""
        self.accumulated_gradients = None
        self.accumulation_counter = 0
  
    def get_shape_statistics(self):
        """获取形状统计信息"""
        stats = {}
      
        for key, values in self.shape_statistics.items():
            if values:
                stats[f'{key}_mean'] = np.mean(values)
                stats[f'{key}_std'] = np.std(values)
                stats[f'{key}_min'] = np.min(values)
                stats[f'{key}_max'] = np.max(values)
                stats[f'{key}_unique'] = len(np.unique(values))
      
        stats['recompilation_count'] = self.recompilation_count
        stats['cache_hit_rate'] = self.cache_hit_rate
      
        return stats

class DynamicBatchSampler:
    """动态批采样器 - 根据序列长度动态调整批大小"""
  
    def __init__(self, 
                 dataset_lengths,  # 每个样本的长度
                 max_tokens_per_batch: int = 4096,
                 max_sequences_per_batch: int = 32,
                 shuffle: bool = True):
      
        self.dataset_lengths = dataset_lengths
        self.max_tokens_per_batch = max_tokens_per_batch
        self.max_sequences_per_batch = max_sequences_per_batch
        self.shuffle = shuffle
      
        # 索引数组
        self.indices = np.arange(len(dataset_lengths))
      
        # 当前批次
        self.current_batch = []
        self.current_tokens = 0
      
    def __iter__(self):
        """迭代器"""
        if self.shuffle:
            np.random.shuffle(self.indices)
      
        self.current_batch = []
        self.current_tokens = 0
      
        for idx in self.indices:
            sample_length = self.dataset_lengths[idx]
          
            # 检查是否可以添加到当前批次
            if (len(self.current_batch) < self.max_sequences_per_batch and
                self.current_tokens + sample_length <= self.max_tokens_per_batch):
              
                self.current_batch.append(idx)
                self.current_tokens += sample_length
            else:
                # 返回当前批次
                if self.current_batch:
                    yield self.current_batch
              
                # 开始新批次
                self.current_batch = [idx]
                self.current_tokens = sample_length
      
        # 返回最后一批
        if self.current_batch:
            yield self.current_batch
  
    def __len__(self):
        """估计批次数"""
        # 这里简化为固定估计,实际需要动态计算
        return len(self.indices) // self.max_sequences_per_batch

二、稀疏计算高级特性

2.1 稀疏张量基础

# sparse_tensor_basics.py
import mindspore as ms
from mindspore import Tensor, CSRTensor, COOTensor
import numpy as np
from scipy import sparse

class SparseTensorFactory:
    """稀疏张量工厂"""
  
    @staticmethod
    def dense_to_csr(dense_tensor: Tensor, threshold: float = 0.0):
        """稠密张量转CSR格式"""
        dense_np = dense_tensor.asnumpy()
      
        # 创建稀疏矩阵
        sparse_matrix = sparse.csr_matrix(dense_np)
      
        # 应用阈值(可选)
        if threshold > 0:
            sparse_matrix.data[np.abs(sparse_matrix.data) < threshold] = 0
            sparse_matrix.eliminate_zeros()
      
        # 转换为MindSpore CSRTensor
        indptr = Tensor(sparse_matrix.indptr, dtype=ms.int32)
        indices = Tensor(sparse_matrix.indices, dtype=ms.int32)
        values = Tensor(sparse_matrix.data, dtype=dense_tensor.dtype)
        shape = dense_tensor.shape
      
        return CSRTensor(indptr, indices, values, shape)
  
    @staticmethod
    def dense_to_coo(dense_tensor: Tensor, threshold: float = 0.0):
        """稠密张量转COO格式"""
        dense_np = dense_tensor.asnumpy()
      
        # 创建稀疏矩阵
        sparse_matrix = sparse.coo_matrix(dense_np)
      
        # 应用阈值(可选)
        if threshold > 0:
            mask = np.abs(sparse_matrix.data) >= threshold
            sparse_matrix = sparse.coo_matrix(
                (sparse_matrix.data[mask],
                 (sparse_matrix.row[mask], sparse_matrix.col[mask])),
                shape=sparse_matrix.shape
            )
      
        # 转换为MindSpore COOTensor
        indices = Tensor(np.stack([sparse_matrix.row, sparse_matrix.col], axis=1), 
                        dtype=ms.int32)
        values = Tensor(sparse_matrix.data, dtype=dense_tensor.dtype)
        shape = dense_tensor.shape
      
        return COOTensor(indices, values, shape)
  
    @staticmethod
    def create_random_sparse(shape, density=0.1, format='csr'):
        """创建随机稀疏张量"""
        total_elements = np.prod(shape)
        num_nonzero = int(total_elements * density)
      
        # 生成随机位置和值
        indices = np.random.choice(total_elements, num_nonzero, replace=False)
        values = np.random.randn(num_nonzero).astype(np.float32)
      
        # 转换为坐标
        coords = np.unravel_index(indices, shape)
      
        if format == 'coo':
            # COO格式
            indices_tensor = Tensor(np.stack(coords, axis=1), dtype=ms.int32)
            values_tensor = Tensor(values, dtype=ms.float32)
            return COOTensor(indices_tensor, values_tensor, shape)
      
        elif format == 'csr':
            # CSR格式(假设是2D矩阵)
            if len(shape) != 2:
                raise ValueError("CSR格式仅支持2D张量")
          
            rows, cols = coords
            sparse_matrix = sparse.csr_matrix((values, (rows, cols)), shape=shape)
          
            indptr = Tensor(sparse_matrix.indptr, dtype=ms.int32)
            indices = Tensor(sparse_matrix.indices, dtype=ms.int32)
            values_tensor = Tensor(sparse_matrix.data, dtype=ms.float32)
          
            return CSRTensor(indptr, indices, values_tensor, shape)
  
    @staticmethod
    def analyze_sparsity(tensor):
        """分析稀疏性"""
        if isinstance(tensor, (CSRTensor, COOTensor)):
            nnz = tensor.values.shape[0]
            total = np.prod(tensor.shape)
            density = nnz / total
          
            return {
                'format': type(tensor).__name__,
                'shape': tensor.shape,
                'nnz': nnz,
                'total': total,
                'density': density,
                'sparsity': 1 - density,
                'storage_saving': (1 - (nnz * 2 + (len(tensor.shape) + 1)) / total) * 100
            }
        else:
            # 稠密张量
            total = np.prod(tensor.shape)
            nnz = np.count_nonzero(tensor.asnumpy())
            density = nnz / total
          
            return {
                'format': 'dense',
                'shape': tensor.shape,
                'nnz': nnz,
                'total': total,
                'density': density,
                'sparsity': 1 - density
            }

class SparseOperations:
    """稀疏张量操作"""
  
    @staticmethod
    def sparse_matmul(sparse_tensor, dense_tensor):
        """稀疏-稠密矩阵乘法"""
        if isinstance(sparse_tensor, CSRTensor):
            # CSR格式矩阵乘法
            return ms.ops.csr_mm(sparse_tensor, dense_tensor)
        elif isinstance(sparse_tensor, COOTensor):
            # COO格式矩阵乘法
            return ms.ops.coo_mm(sparse_tensor, dense_tensor)
        else:
            raise TypeError(f"不支持的稀疏格式: {type(sparse_tensor)}")
  
    @staticmethod
    def sparse_add(sparse_tensor, dense_tensor):
        """稀疏-稠密加法"""
        if isinstance(sparse_tensor, CSRTensor):
            return ms.ops.csr_add(sparse_tensor, dense_tensor)
        elif isinstance(sparse_tensor, COOTensor):
            return ms.ops.coo_add(sparse_tensor, dense_tensor)
  
    @staticmethod
    def sparse_conv2d(sparse_tensor, weight, stride=1, padding=0):
        """稀疏卷积"""
        # 转换稀疏张量为稠密进行卷积
        dense_tensor = sparse_tensor.to_dense()
        return ms.ops.conv2d(dense_tensor, weight, stride=stride, padding=padding)
  
    @staticmethod
    def sparse_attention(query, key, value, sparse_mask=None):
        """稀疏注意力机制"""
        # 计算注意力分数
        scores = ms.ops.matmul(query, key.transpose(0, 1, 3, 2))
      
        # 应用稀疏掩码
        if sparse_mask is not None:
            if isinstance(sparse_mask, (CSRTensor, COOTensor)):
                # 转换为稠密掩码
                sparse_mask = sparse_mask.to_dense()
            scores = scores * sparse_mask
      
        # softmax
        attention_weights = ms.ops.softmax(scores, axis=-1)
      
        # 注意力输出
        output = ms.ops.matmul(attention_weights, value)
      
        return output

2.2 稀疏神经网络层

# sparse_neural_layers.py
class SparseLinear(nn.Cell):
    """稀疏线性层"""
  
    def __init__(self, 
                 in_features: int,
                 out_features: int,
                 sparsity: float = 0.9,
                 sparse_format: str = 'csr',
                 bias: bool = True):
    
        super().__init__()
    
        self.in_features = in_features
        self.out_features = out_features
        self.sparsity = sparsity
        self.sparse_format = sparse_format
        self.has_bias = bias
    
        # 初始化权重(稀疏)
        self.weight = self._init_sparse_weight()
    
        # 偏置
        if bias:
            self.bias = ms.Parameter(
                ms.ops.zeros(out_features, ms.float32)
            )
        else:
            self.bias = None
    
        # 稀疏操作器
        self.sparse_ops = SparseOperations()
  
    def _init_sparse_weight(self):
        """初始化稀疏权重"""
        # 创建随机稀疏权重
        shape = (self.out_features, self.in_features)
    
        if self.sparse_format == 'csr':
            weight_tensor = SparseTensorFactory.create_random_sparse(
                shape, density=1-self.sparsity, format='csr'
            )
        elif self.sparse_format == 'coo':
            weight_tensor = SparseTensorFactory.create_random_sparse(
                shape, density=1-self.sparsity, format='coo'
            )
        else:
            raise ValueError(f"不支持的稀疏格式: {self.sparse_format}")