From af06d0bbdaa12cfa2112e3ec65058d9e16a0a984 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E5=90=B4=E5=A7=BF=E8=8A=9D?=
 <16377376+zizi05@user.noreply.gitee.com>
Date: Sat, 22 Nov 2025 15:44:18 +0800
Subject: [PATCH] feat:add pairwise_distance #3

---
 S1/zizi05_#3/pairwise_distance_cudacode.py  |  89 +++++++++++++++
 S1/zizi05_#3/pairwise_distance_torchcode.py |  41 +++++++
 S1/zizi05_#3/prompt.txt                     | 113 ++++++++++++++++++++
 S1/zizi05_#3/run_code.py                    |  74 +++++++++++++
 4 files changed, 317 insertions(+)
 create mode 100644 S1/zizi05_#3/pairwise_distance_cudacode.py
 create mode 100644 S1/zizi05_#3/pairwise_distance_torchcode.py
 create mode 100644 S1/zizi05_#3/prompt.txt
 create mode 100644 S1/zizi05_#3/run_code.py

diff --git a/S1/zizi05_#3/pairwise_distance_cudacode.py b/S1/zizi05_#3/pairwise_distance_cudacode.py
new file mode 100644
index 00000000..2e299c72
--- /dev/null
+++ b/S1/zizi05_#3/pairwise_distance_cudacode.py
@@ -0,0 +1,89 @@
+import torch
+from torch.utils.cpp_extension import load_inline
+
+# 高效的成对距离 CUDA 源码
+pairwise_distance_source = """
+#include <torch/extension.h>
+#include <cuda_runtime.h>
+#include <math.h>
+
+// Kernel to compute pairwise Euclidean distance
+// Each thread computes one element of the output distance matrix.
+__global__ void pairwise_distance_kernel(
+    const float* __restrict__ x, 
+    const float* __restrict__ y, 
+    float* __restrict__ dist,
+    int N, int M, int D
+) {
+    // 2D thread mapping
+    int row = blockIdx.y * blockDim.y + threadIdx.y; // Maps to N
+    int col = blockIdx.x * blockDim.x + threadIdx.x; // Maps to M
+
+    if (row < N && col < M) {
+        // Pointer to the start of the vectors for this thread's computation
+        const float* x_vec = x + row * D;
+        const float* y_vec = y + col * D;
+        
+        float sum_sq = 0.0f;
+        // Compute the sum of squared differences
+        for (int k = 0; k < D; ++k) {
+            float diff = x_vec[k] - y_vec[k];
+            sum_sq += diff * diff;
+        }
+        
+        // Store the final distance
+        dist[row * M + col] = sqrtf(sum_sq);
+    }
+}
+
+torch::Tensor pairwise_distance_cuda(torch::Tensor x, torch::Tensor y) {
+    TORCH_CHECK(x.is_cuda() && x.is_contiguous());
+    TORCH_CHECK(y.is_cuda() && y.is_contiguous());
+    TORCH_CHECK(x.dim() == 2 && y.dim() == 2);
+    TORCH_CHECK(x.size(1) == y.size(1), "Vector dimensions must match");
+
+    int N = x.size(0);
+    int M = y.size(0);
+    int D = x.size(1);
+    
+    auto dist = torch::empty({N, M}, x.options());
+
+    // Use a 2D grid and 2D blocks
+    dim3 block_size(16, 16); // A 16x16 thread block is a good starting point
+    dim3 grid_size((M + block_size.x - 1) / block_size.x, 
+                   (N + block_size.y - 1) / block_size.y);
+
+    pairwise_distance_kernel<<<grid_size, block_size>>>(
+        x.data_ptr<float>(),
+        y.data_ptr<float>(),
+        dist.data_ptr<float>(),
+        N, M, D
+    );
+    
+    return dist;
+}
+"""
+
+pairwise_distance_cpp_source = """
+torch::Tensor pairwise_distance_cuda(torch::Tensor x, torch::Tensor y);
+"""
+
+# 编译模块
+pairwise_distance_module = load_inline(
+    name="pairwise_distance",
+    cpp_sources=pairwise_distance_cpp_source,
+    cuda_sources=pairwise_distance_source,
+    functions=["pairwise_distance_cuda"],
+    verbose=True,
+    extra_cuda_cflags=["-O3", "--use_fast_math"]
+)
+
+class ModelNew(torch.nn.Module):
+    def __init__(self):
+        super(ModelNew, self).__init__()
+        self.pairwise_distance = pairwise_distance_module
+
+    def forward(self, x, y):
+        if not x.is_contiguous(): x = x.contiguous()
+        if not y.is_contiguous(): y = y.contiguous()
+        return self.pairwise_distance.pairwise_distance_cuda(x, y)
diff --git a/S1/zizi05_#3/pairwise_distance_torchcode.py b/S1/zizi05_#3/pairwise_distance_torchcode.py
new file mode 100644
index 00000000..bbe02704
--- /dev/null
+++ b/S1/zizi05_#3/pairwise_distance_torchcode.py
@@ -0,0 +1,41 @@
+import torch
+import torch.nn as nn
+
+class Model(nn.Module):
+    """
+    Computes the pairwise Euclidean distance matrix between two sets of vectors.
+    This implementation uses broadcasting, which is memory-intensive.
+    """
+    def __init__(self):
+        super(Model, self).__init__()
+    
+    def forward(self, x: torch.Tensor, y: torch.Tensor) -> torch.Tensor:
+        """
+        Args:
+            x (torch.Tensor): A tensor of shape (N, D).
+            y (torch.Tensor): A tensor of shape (M, D).
+
+        Returns:
+            torch.Tensor: A tensor of shape (N, M) where Z[i, j] is the distance
+                          between x[i] and y[j].
+        """
+        # x.unsqueeze(1) -> (N, 1, D)
+        # y.unsqueeze(0) -> (1, M, D)
+        # The result of subtraction is (N, M, D)
+        diff = x.unsqueeze(1) - y.unsqueeze(0)
+        # Compute L2 norm along the last dimension
+        dist_matrix = torch.norm(diff, p=2, dim=-1)
+        return dist_matrix
+
+# 测试数据配置
+N = 1024  # Number of vectors in the first set
+M = 1024  # Number of vectors in the second set
+D = 512   # Dimensionality of each vector
+
+def get_inputs():
+    x = torch.randn(N, D)
+    y = torch.randn(M, D)
+    return [x, y]
+
+def get_init_inputs():
+    return [] # No special initialization inputs needed
diff --git a/S1/zizi05_#3/prompt.txt b/S1/zizi05_#3/prompt.txt
new file mode 100644
index 00000000..40723a2f
--- /dev/null
+++ b/S1/zizi05_#3/prompt.txt
@@ -0,0 +1,113 @@
+You write custom CUDA kernels to replace the PyTorch operators in the given Pairwise Euclidean Distance 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 the combined broadcasting subtraction and L2 norm operators with a custom CUDA kernel (considering operator fusion opportunities to combine the element-wise difference calculation, sum of squares, and square root into a single kernel) or adjust algorithms for better performance. You are only limited by your imagination.
+
+Here's an example to show you the syntax of inline embedding custom CUDA operators in PyTorch (for reference of code structure, not functional alignment):
+The example given architecture (sample structure):
+import torch
+import torch.nn as nn
+import torch.nn.functional as F
+class Model(nn.Module):
+    def __init__(self) -> None:
+        super().__init__()
+    def forward(self, a, b):
+        return a + b
+def get_inputs():
+    # randomly generate input tensors based on the model architecture
+    a = torch.randn(1, 128).cuda()
+    b = torch.randn(1, 128).cuda()
+    return [a, b]
+def get_init_inputs():
+    # randomly generate tensors required for initialization based on the model architecture
+    return []
+
+The example new arch with custom CUDA kernels (sample structure):
+import torch
+import torch.nn as nn
+import torch.nn.functional as F
+from torch.utils.cpp_extension import load_inline
+# Define custom CUDA kernel and load it inline
+custom_add_source = """
+#include <torch/extension.h>
+#include <cuda_runtime.h>
+__global__ void custom_add_kernel(const float* a, const float* b, float* out, int size) {
+    int idx = blockIdx.x * blockDim.x + threadIdx.x;
+    if (idx < size) {
+        out[idx] = a[idx] + b[idx];
+    }
+}
+torch::Tensor custom_add_cuda(torch::Tensor a, torch::Tensor b) {
+    auto size = a.numel();
+    auto out = torch::empty_like(a);
+    const int block_size = 256;
+    int num_blocks = (size + block_size - 1) / block_size;
+    custom_add_kernel<<<num_blocks, block_size>>>(a.data_ptr<float>(), b.data_ptr<float>(), out.data_ptr<float>(), size);
+    return out;
+}
+"""
+custom_add_cpp_source = "torch::Tensor custom_add_cuda(torch::Tensor a, torch::Tensor b);"
+custom_add = load_inline(
+    name="custom_add",
+    cpp_sources=custom_add_cpp_source,
+    cuda_sources=custom_add_source,
+    functions=["custom_add_cuda"],
+    verbose=True
+)
+class Model(nn.Module):
+    def __init__(self) -> None:
+        super().__init__()
+        self.custom_add = custom_add
+    def forward(self, a, b):
+        return self.custom_add.custom_add_cuda(a, b)
+def get_inputs():
+    # randomly generate input tensors based on the model architecture
+    a = torch.randn(1, 128).cuda()
+    b = torch.randn(1, 128).cuda()
+    return [a, b]
+def get_init_inputs():
+    # randomly generate tensors required for initialization based on the model architecture
+    return []
+
+You are given the following Pairwise Euclidean Distance architecture (base PyTorch implementation):
+import torch
+import torch.nn as nn
+class Model(nn.Module):
+    """
+    Pairwise Euclidean Distance function: Mathematical formulation is ||x_i - y_j||_2 for each pair (x_i, y_j),
+    where x_i is the i-th vector in input x (shape (N, D)), y_j is the j-th vector in input y (shape (M, D)),
+    and ||·||_2 denotes the L2 norm (Euclidean distance).
+    """
+    def __init__(self):
+        super(Model, self).__init__()
+    
+    def forward(self, x: torch.Tensor, y: torch.Tensor) -> torch.Tensor:
+        """
+        Computes the pairwise Euclidean distance matrix between two sets of vectors.
+        Args:
+            x (torch.Tensor): Input tensor with fixed shape (N, D)
+                              where N=1024 (number of vectors in first set) and D=512 (dimensionality of each vector).
+            y (torch.Tensor): Input tensor with fixed shape (M, D)
+                              where M=1024 (number of vectors in second set) and D=512 (dimensionality of each vector).
+        Returns:
+            torch.Tensor: Output tensor of shape (N, M) where each element [i, j] is the Euclidean distance between x[i] and y[j].
+        """
+        # x.unsqueeze(1) -> (N, 1, D), y.unsqueeze(0) -> (1, M, D)
+        # Broadcasting subtraction results in (N, M, D)
+        diff = x.unsqueeze(1) - y.unsqueeze(0)
+        # Compute L2 norm along the last dimension to get (N, M) distance matrix
+        dist_matrix = torch.norm(diff, p=2, dim=-1)
+        return dist_matrix
+
+# Fixed hyperparameters for input generation
+N = 1024  # Number of vectors in the first set
+M = 1024  # Number of vectors in the second set
+D = 512   # Dimensionality of each vector
+
+def get_inputs():
+    # Randomly generate input tensors matching the fixed shapes (N, D) and (M, D)
+    x = torch.randn(N, D)
+    y = torch.randn(M, D)
+    return [x, y]
+
+def get_init_inputs():
+    # No special initialization tensors needed (model has no trainable parameters)
+    return []
\ No newline at end of file
diff --git a/S1/zizi05_#3/run_code.py b/S1/zizi05_#3/run_code.py
new file mode 100644
index 00000000..659038f9
--- /dev/null
+++ b/S1/zizi05_#3/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 pairwise_distance_torchcode import Model,get_inputs,get_init_inputs
+from pairwise_distance_cudacode 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 pairwise_distance 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