Merge pull request 'finish VandermondeMatrix #82' (#646) from ZZZJ/GPUCodeForces:VandermondeMatrix into main

This commit is contained in:
wawahejun 2025-12-14 19:44:57 +08:00
commit c676d8d308
4 changed files with 195 additions and 0 deletions

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S1/ZZZJ_#82/prompt.txt Normal file
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You write custom CUDA kernels to replace the pytorch operators in the given architecture to get speedups.
You have complete freedom to choose the set of operators you want to replace. You may make the decision to replace some operators with custom CUDA kernels and leave others unchanged. You may replace multiple operators with custom implementations, consider operator fusion opportunities (combining multiple operators into a single kernel, for example, combining matmul+relu), or algorithmic changes (such as online softmax). You are only limited by your imagination.
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
class Model(nn.Module):
def __init__(self, N=64):
super().__init__()
self.N = N
def forward(self, x: torch.Tensor) -> torch.Tensor:
return torch.vander(x, N=self.N, increasing=False)
num_points = 1024 * 1024
degree = 64
def get_inputs():
x = torch.rand(num_points, dtype=torch.float32)
return [x]
def get_init_inputs():
return [degree]
```

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S1/ZZZJ_#82/run_code.py Normal file
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###########################################################
# 性能和精度验证程序
###########################################################
import torch
import torch.nn as nn
import time
from vandermonde_matrix_torch import Model,get_inputs,get_init_inputs
from vandermonde_matrix_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}")
print(f"自定义 CUDA 内核 平均执行时间: {cuda_time:.6f}")
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()

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import torch
import torch.nn as nn
from torch.utils.cpp_extension import load_inline
cpp_src = "torch::Tensor vandermonde_cuda(torch::Tensor x, int N);"
cuda_src = """
#include <cuda_runtime.h>
__global__ void vander_kernel(
const float* __restrict__ x_ptr,
float* __restrict__ output,
int num_points,
int N // Degree (Columns)
) {
int idx = blockIdx.x * blockDim.x + threadIdx.x;
if (idx >= num_points) return;
float val = x_ptr[idx];
int row_offset = idx * N;
float current_pow = 1.0f;
for (int i = N - 1; i >= 0; --i) {
output[row_offset + i] = current_pow;
current_pow *= val;
}
}
torch::Tensor vandermonde_cuda(torch::Tensor x, int N) {
int num_points = x.size(0);
x = x.contiguous();
auto output = torch::empty({num_points, N}, x.options());
const int block_size = 256;
int grid_size = (num_points + block_size - 1) / block_size;
if (grid_size > 2147483647) grid_size = 2147483647;
vander_kernel<<<grid_size, block_size>>>(
x.data_ptr<float>(),
output.data_ptr<float>(),
num_points,
N
);
return output;
}
"""
class ModelNew(nn.Module):
def __init__(self, N=64):
super().__init__()
self.N = N
self.module = load_inline(
name="vandermonde_matrix_opt_v1",
cpp_sources=cpp_src,
cuda_sources=cuda_src,
functions=["vandermonde_cuda"],
verbose=False,
extra_cuda_cflags=["-O3"]
)
def forward(self, x):
return self.module.vandermonde_cuda(x, self.N)

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import torch
import torch.nn as nn
class Model(nn.Module):
def __init__(self, N=64):
super().__init__()
self.N = N
def forward(self, x: torch.Tensor) -> torch.Tensor:
return torch.vander(x, N=self.N, increasing=False)
num_points = 1024 * 1024
degree = 64
def get_inputs():
x = torch.rand(num_points, dtype=torch.float32)
return [x]
def get_init_inputs():
return [degree]