diff --git a/S1/hli28146_#82/GumbelCDF_cuda.py b/S1/hli28146_#82/GumbelCDF_cuda.py new file mode 100644 index 00000000..b3740d60 --- /dev/null +++ b/S1/hli28146_#82/GumbelCDF_cuda.py @@ -0,0 +1,102 @@ +import torch +import torch.nn as nn +from torch.utils.cpp_extension import load_inline + +cpp_source = """ +#include + +torch::Tensor gumbel_cdf_cuda_forward(const torch::Tensor& input); +""" + +cuda_source = """ +#include +#include +#include + +#define BLOCK_SIZE 256 + +struct __align__(16) Float4 { + float x, y, z, w; +}; + +// Gumbel CDF: exp(-exp(-x)) +__device__ __forceinline__ float compute_gumbel_cdf(float x) { + // Clamp to prevent exp(-x) overflow for large negative x + float neg_x = fminf(-x, 80.0f); + float inner_exp = __expf(neg_x); + return __expf(-inner_exp); +} + +__global__ void gumbel_cdf_kernel( + float* __restrict__ output, + const float* __restrict__ input, + const int n) +{ + const int idx = blockIdx.x * blockDim.x + threadIdx.x; + const int vec_n = n / 4; + + int i = idx; + const int stride = blockDim.x * gridDim.x; + + for (; i < vec_n; i += stride) { + Float4 in_vec = reinterpret_cast(input)[i]; + Float4 out_vec; + + out_vec.x = compute_gumbel_cdf(in_vec.x); + out_vec.y = compute_gumbel_cdf(in_vec.y); + out_vec.z = compute_gumbel_cdf(in_vec.z); + out_vec.w = compute_gumbel_cdf(in_vec.w); + + reinterpret_cast(output)[i] = out_vec; + } + + int start_scalar = vec_n * 4; + int global_tid = blockIdx.x * blockDim.x + threadIdx.x; + int total_threads = gridDim.x * gridDim.x; + + int current_idx = start_scalar + global_tid; + while (current_idx < n) { + output[current_idx] = compute_gumbel_cdf(input[current_idx]); + current_idx += total_threads; + } +} + +torch::Tensor gumbel_cdf_cuda_forward(const torch::Tensor& input) { + TORCH_CHECK(input.is_cuda(), "Input must be a CUDA tensor"); + TORCH_CHECK(input.is_contiguous(), "Input must be contiguous"); + + const int n = input.numel(); + auto output = torch::empty_like(input); + + const int vec_n = n / 4; + const int grid_size = (vec_n + BLOCK_SIZE - 1) / BLOCK_SIZE; + + int final_grid = (grid_size < 1) ? 1 : grid_size; + if (final_grid > 65535) final_grid = 65535; + + gumbel_cdf_kernel<<>>( + output.data_ptr(), + input.data_ptr(), + n + ); + + return output; +} +""" + +gumbel_cdf_op_module = load_inline( + name='gumbel_cdf_op', + cpp_sources=cpp_source, + cuda_sources=cuda_source, + functions=['gumbel_cdf_cuda_forward'], + verbose=False, + extra_cuda_cflags=['-O3', '--use_fast_math'] +) + +class ModelNew(nn.Module): + def __init__(self): + super(ModelNew, self).__init__() + self.op = gumbel_cdf_op_module + + def forward(self, input_tensor: torch.Tensor) -> torch.Tensor: + return self.op.gumbel_cdf_cuda_forward(input_tensor.contiguous()) \ No newline at end of file diff --git a/S1/hli28146_#82/GumbelCDF_torch.py b/S1/hli28146_#82/GumbelCDF_torch.py new file mode 100644 index 00000000..3d865259 --- /dev/null +++ b/S1/hli28146_#82/GumbelCDF_torch.py @@ -0,0 +1,36 @@ +import torch +import torch.nn as nn + +BATCH_SIZE = 4096 +HIDDEN_DIM = 4096 +SHAPE = (BATCH_SIZE, HIDDEN_DIM) + +class GumbelCDF(nn.Module): + """ + Gumbel Cumulative Distribution Function (CDF). + f(x) = exp(-exp(-x)) + """ + def __init__(self, clamp_val=80.0): + super(GumbelCDF, self).__init__() + self.clamp_val = clamp_val + + def forward(self, x: torch.Tensor) -> torch.Tensor: + neg_x = torch.clamp(-x, max=self.clamp_val) + inner_exp = torch.exp(neg_x) + return torch.exp(-inner_exp) + +class Model(nn.Module): + def __init__(self): + super(Model, self).__init__() + self.act = GumbelCDF() + + def forward(self, x): + return self.act(x) + +def get_inputs(): + # 覆盖正负区间 + input_tensor = torch.randn(SHAPE, dtype=torch.float32) * 20.0 + return [input_tensor.contiguous()] + +def get_init_inputs(): + return [] \ No newline at end of file diff --git a/S1/hli28146_#82/prompt.txt b/S1/hli28146_#82/prompt.txt new file mode 100644 index 00000000..153d1aa5 --- /dev/null +++ b/S1/hli28146_#82/prompt.txt @@ -0,0 +1,63 @@ +Write a custom CUDA kernel to optimize the `Gumbel CDF` as an activation function. + +Formula: f(x) = exp(-exp(-x)) + +Problem Analysis: +1. Computationally Intensive: This operation involves a double exponential, which is arithmetically heavy for an element-wise activation. +2. Memory Bottleneck: A standard PyTorch implementation `torch.exp(-torch.exp(-x))` chains three separate kernels, creating two intermediate tensors and high memory traffic. +3. Numerical Stability: The inner `exp(-x)` can overflow if `x` is a large negative number. + +Optimization Strategy: Fused Element-wise Kernel with Vectorization + +1. One-Thread-per-Element: Map each element to a CUDA thread. + +2. Vectorized Loads (float4): Use `float4` to process 128 bits per memory transaction. + +3. Fused Stable Math: + - For each element `x`, first compute `inner_val = -x`. + - Clamp `inner_val` to a safe upper bound (e.g., 80.0) to prevent `exp` overflow. + - Compute `exp1 = __expf(clamped_inner_val)`. + - Compute `result = __expf(-exp1)`. + - All steps are fused in registers. + +4. One-Pass: Fuse all logic into a single read-compute-write kernel. + +Here's an example to show you the syntax of inline embedding custom CUDA operators in torch: The example given architecture is: + +```python +import torch +import torch.nn as nn + +BATCH_SIZE = 4096 +HIDDEN_DIM = 4096 +SHAPE = (BATCH_SIZE, HIDDEN_DIM) + +class GumbelCDF(nn.Module): + """ + Gumbel Cumulative Distribution Function (CDF). + f(x) = exp(-exp(-x)) + """ + def __init__(self, clamp_val=80.0): + super(GumbelCDF, self).__init__() + self.clamp_val = clamp_val + + def forward(self, x: torch.Tensor) -> torch.Tensor: + neg_x = torch.clamp(-x, max=self.clamp_val) + inner_exp = torch.exp(neg_x) + return torch.exp(-inner_exp) + +class Model(nn.Module): + def __init__(self): + super(Model, self).__init__() + self.act = GumbelCDF() + + def forward(self, x): + return self.act(x) + +def get_inputs(): + # 覆盖正负区间 + input_tensor = torch.randn(SHAPE, dtype=torch.float32) * 20.0 + return [input_tensor.contiguous()] + +def get_init_inputs(): + return [] \ No newline at end of file diff --git a/S1/hli28146_#82/run_code.py b/S1/hli28146_#82/run_code.py new file mode 100644 index 00000000..7a11e0e8 --- /dev/null +++ b/S1/hli28146_#82/run_code.py @@ -0,0 +1,74 @@ +########################################################### +# 性能和精度验证程序 +########################################################### +import torch +import torch.nn as nn +import time +from GumbelCDF_torch import Model,get_inputs,get_init_inputs +from GumbelCDF_cuda import ModelNew + +def run_benchmark(): + # 检查 CUDA 是否可用 + if not torch.cuda.is_available(): + print("CUDA 不可用,请确保您有可用的 NVIDIA GPU 并已正确安装 PyTorch CUDA 版本。") + return + else: + device = torch.device("cuda") + + # 初始化模型 + init_inputs = get_init_inputs() + init_inputs = [ + x.cuda(device=device) if isinstance(x, torch.Tensor) else x for x in init_inputs + ] + inputs = get_inputs() + inputs = [ + x.cuda(device=device) if isinstance(x, torch.Tensor) else x for x in inputs + ] + + torch_model = Model(*init_inputs).cuda() + cuda_model = ModelNew(*init_inputs).cuda() + + torch_model.eval() + cuda_model.eval() + + print("-------------------- 精度对齐验证 --------------------") + with torch.no_grad(): + output_torch = torch_model( *inputs) + output_cuda = cuda_model(*inputs) + + precision_flag = torch.allclose(output_torch, output_cuda,rtol=1e-03) + if precision_flag: + print("✅ 精度对齐:两个模型的输出结果非常接近。") + else: + print("❌ 精度不一致!") + + print("\n-------------------- 性能加速比测试 --------------------") + num_iterations = 100 + + # PyTorch 模型计时 + torch.cuda.synchronize() + start_time = time.time() + for _ in range(num_iterations): + _ = torch_model(*inputs) + torch.cuda.synchronize() + torch_time = (time.time() - start_time) / num_iterations + + # 自定义 CUDA 内核计时 + torch.cuda.synchronize() + start_time = time.time() + for _ in range(num_iterations): + _ = cuda_model(*inputs) + torch.cuda.synchronize() + cuda_time = (time.time() - start_time) / num_iterations + + print(f"PyTorch torch.relu 平均执行时间: {torch_time:.6f} 秒") + print(f"自定义 CUDA 内核 平均执行时间: {cuda_time:.6f} 秒") + speedup = 0 + if cuda_time > 0: + speedup = torch_time / cuda_time + print(f"加速比 (Speedup): {speedup:.2f}x") + else: + print("CUDA 内核执行时间为0,无法计算加速比。") + return precision_flag,speedup +if __name__ == "__main__": + precision_flag,speedup = run_benchmark() \ No newline at end of file