Merge pull request 'fix CosineEmbeddingLoss #15' (#122) from gsd123/GPUCodeForces:gsd15 into main

This commit is contained in:
Kuohais 2025-11-14 13:40:05 +08:00
commit ef92efd7c1
4 changed files with 457 additions and 0 deletions

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import torch
import torch.nn as nn
from torch.utils.cpp_extension import load_inline
N, C, H, W = 32, 64, 56, 56
EPS = 1e-8
assert (C * H * W) % 4 == 0, "Instance size (C*H*W) must be a multiple of 4"
class ModelNew(nn.Module):
def __init__(self, margin=0.5):
super().__init__()
self.margin = margin
self.eps = EPS
self.block_size = 256
self._compile_cuda_kernel()
def _compile_cuda_kernel(self):
cpp_source = """
#include <torch/extension.h>
torch::Tensor cosine_loss_forward_cuda(
torch::Tensor x1,
torch::Tensor x2,
torch::Tensor target,
float margin,
float eps,
int N,
int D);
"""
cuda_source = f"""
#include <cuda_runtime.h>
#include <cmath>
#define BLOCK_SIZE {self.block_size}
#define WARP_SIZE 32
#define ILP 4
__inline__ __device__ float warp_reduce_sum(float val) {{
#pragma unroll
for (int offset = WARP_SIZE / 2; offset > 0; offset /= 2) {{
val += __shfl_down_sync(0xffffffff, val, offset);
}}
return val;
}}
__global__ void cosine_embedding_kernel(
const float* __restrict__ x1,
const float* __restrict__ x2,
const float* __restrict__ target,
float* __restrict__ output,
float margin,
float eps,
int D_vec // D / 4
) {{
const int n_idx = blockIdx.x;
const int offset = n_idx * D_vec * 4;
const float4* x1_ptr = reinterpret_cast<const float4*>(x1 + offset);
const float4* x2_ptr = reinterpret_cast<const float4*>(x2 + offset);
float sum_dot = 0.0f;
float sum_sq1 = 0.0f;
float sum_sq2 = 0.0f;
for (int i = threadIdx.x * ILP; i < D_vec; i += blockDim.x * ILP) {{
float4 r1[ILP];
float4 r2[ILP];
#pragma unroll
for (int k = 0; k < ILP; ++k) {{
if (i + k < D_vec) {{
r1[k] = __ldg(&x1_ptr[i + k]);
r2[k] = __ldg(&x2_ptr[i + k]);
}} else {{
r1[k] = make_float4(0.f, 0.f, 0.f, 0.f);
r2[k] = make_float4(0.f, 0.f, 0.f, 0.f);
}}
}}
// 2. 计算累加
#pragma unroll
for (int k = 0; k < ILP; ++k) {{
// Dot Product
sum_dot += r1[k].x * r2[k].x;
sum_dot += r1[k].y * r2[k].y;
sum_dot += r1[k].z * r2[k].z;
sum_dot += r1[k].w * r2[k].w;
// Norm Sq 1
sum_sq1 += r1[k].x * r1[k].x;
sum_sq1 += r1[k].y * r1[k].y;
sum_sq1 += r1[k].z * r1[k].z;
sum_sq1 += r1[k].w * r1[k].w;
// Norm Sq 2
sum_sq2 += r2[k].x * r2[k].x;
sum_sq2 += r2[k].y * r2[k].y;
sum_sq2 += r2[k].z * r2[k].z;
sum_sq2 += r2[k].w * r2[k].w;
}}
}}
__shared__ float shared_data[32][3];
int lane = threadIdx.x % WARP_SIZE;
int wid = threadIdx.x / WARP_SIZE;
sum_dot = warp_reduce_sum(sum_dot);
sum_sq1 = warp_reduce_sum(sum_sq1);
sum_sq2 = warp_reduce_sum(sum_sq2);
if (lane == 0) {{
shared_data[wid][0] = sum_dot;
shared_data[wid][1] = sum_sq1;
shared_data[wid][2] = sum_sq2;
}}
__syncthreads();
if (wid == 0) {{
// 读取
sum_dot = (threadIdx.x < blockDim.x / WARP_SIZE) ? shared_data[lane][0] : 0.0f;
sum_sq1 = (threadIdx.x < blockDim.x / WARP_SIZE) ? shared_data[lane][1] : 0.0f;
sum_sq2 = (threadIdx.x < blockDim.x / WARP_SIZE) ? shared_data[lane][2] : 0.0f;
sum_dot = warp_reduce_sum(sum_dot);
sum_sq1 = warp_reduce_sum(sum_sq1);
sum_sq2 = warp_reduce_sum(sum_sq2);
if (threadIdx.x == 0) {{
float norm1 = sqrtf(sum_sq1);
float norm2 = sqrtf(sum_sq2);
float cos_sim = sum_dot / (norm1 * norm2 + eps);
float t_val = target[n_idx];
float loss = 0.0f;
if (t_val == 1.0f) {{
loss = 1.0f - cos_sim;
}} else {{
loss = fmaxf(0.0f, cos_sim - margin);
}}
output[n_idx] = loss;
}}
}}
}}
torch::Tensor cosine_loss_forward_cuda(
torch::Tensor x1,
torch::Tensor x2,
torch::Tensor target,
float margin,
float eps,
int N,
int D)
{{
x1 = x1.contiguous();
x2 = x2.contiguous();
target = target.contiguous();
auto output = torch::empty({{N}}, x1.options());
int D_vec = D / 4;
// Grid = Batch Size, Block = 256
dim3 blocks(N);
dim3 threads(BLOCK_SIZE);
cosine_embedding_kernel<<<blocks, threads>>>(
x1.data_ptr<float>(),
x2.data_ptr<float>(),
target.data_ptr<float>(),
output.data_ptr<float>(),
margin,
eps,
D_vec
);
return output;
}}
"""
self.op = load_inline(
name='cosine_loss_cuda_v1',
cpp_sources=cpp_source,
cuda_sources=cuda_source,
functions=['cosine_loss_forward_cuda'],
extra_cuda_cflags=['-O3', '--use_fast_math'],
verbose=False
)
def forward(self, x1: torch.Tensor, x2: torch.Tensor, target: torch.Tensor) -> torch.Tensor:
x1_flat = x1.view(x1.size(0), -1)
x2_flat = x2.view(x2.size(0), -1)
if not x1_flat.is_cuda: x1_flat = x1_flat.cuda()
if not x2_flat.is_cuda: x2_flat = x2_flat.cuda()
if not target.is_cuda: target = target.cuda()
N, D = x1_flat.shape
out = self.op.cosine_loss_forward_cuda(
x1_flat,
x2_flat,
target,
self.margin,
self.eps,
N,
D
)
return out.mean()

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import torch
import torch.nn as nn
import torch.nn.functional as F
N, C, H, W = 32, 64, 56, 56
EPS = 1e-8
class CosineEmbeddingLossCustom(nn.Module):
def __init__(self, margin=0.0, reduction='mean', eps=1e-8):
super().__init__()
self.margin = margin
self.reduction = reduction
self.eps = eps
def forward(self, x1: torch.Tensor, x2: torch.Tensor, target: torch.Tensor) -> torch.Tensor:
dot_product = torch.sum(x1 * x2, dim=1)
norm_x1 = torch.norm(x1, p=2, dim=1)
norm_x2 = torch.norm(x2, p=2, dim=1)
cos_sim = dot_product / (norm_x1 * norm_x2 + self.eps)
loss_pos = 1.0 - cos_sim
loss_neg = F.relu(cos_sim - self.margin)
loss = torch.where(target == 1, loss_pos, loss_neg)
if self.reduction == 'mean':
return loss.mean()
elif self.reduction == 'sum':
return loss.sum()
else:
return loss
class Model(nn.Module):
def __init__(self, margin=0.5):
super().__init__()
self.op = CosineEmbeddingLossCustom(margin=margin, reduction='mean', eps=EPS)
def forward(self, x1: torch.Tensor, x2: torch.Tensor, target: torch.Tensor) -> torch.Tensor:
x1_flat = x1.view(x1.size(0), -1)
x2_flat = x2.view(x2.size(0), -1)
return self.op(x1_flat, x2_flat, target)
def get_inputs():
x1 = torch.randn(N, C, H, W, dtype=torch.float32)
x2 = torch.randn(N, C, H, W, dtype=torch.float32)
target = torch.randint(0, 2, (N,), dtype=torch.float32) # 0 or 1
target = torch.where(target == 0, torch.tensor(-1.0), torch.tensor(1.0))
return [x1, x2, target]
def get_init_inputs():
return [0.5]

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S1/gsd123_#15/prompt.txt Normal file
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You write custom CUDA kernels to replace the PyTorch operators in the given EvoNorm 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 normalization+affine_transform+nonlinear_gating), or algorithmic changes (such as optimized memory access patterns). You are only limited by your imagination.
Technical Overview: CUDA-Optimized Cosine Embedding Loss
This implementation provides a high-performance CUDA kernel for computing cosine embedding loss, designed for deep learning applications with optimized memory access and parallel computation.
Key Features:
Architecture:
Custom CUDA kernel with inline compilation using PyTorch C++ extensions
Optimized for NVIDIA GPUs with warp-level parallelism and shared memory utilization
Supports 4-element vectorization (float4) for memory coalescing
Performance Optimizations:
Vectorized Memory Access: Uses float4 data type to load 4 elements per instruction
Instruction-Level Parallelism (ILP): Processes 4 vectors simultaneously per thread
Warp Reduction: Efficient warp-level reduction operations using __shfl_down_sync
Shared Memory: Intermediate results stored in shared memory for block-level reduction
Memory Coalescing: Contiguous memory access patterns for optimal bandwidth utilization
Kernel Specifications:
Block size: 256 threads
Warp size: 32 threads
Grid dimension: N (batch size)
Input requirement: C×H×W must be divisible by 4 for vectorization
Here's an example to show you the syntax of inline embedding custom CUDA operators in torch: The example given architecture is:
import torch
import torch.nn as nn
import torch.nn.functional as F
N, C, H, W = 32, 64, 56, 56
EPS = 1e-8
class CosineEmbeddingLossCustom(nn.Module):
def __init__(self, margin=0.0, reduction='mean', eps=1e-8):
super().__init__()
self.margin = margin
self.reduction = reduction
self.eps = eps
def forward(self, x1: torch.Tensor, x2: torch.Tensor, target: torch.Tensor) -> torch.Tensor:
dot_product = torch.sum(x1 * x2, dim=1)
norm_x1 = torch.norm(x1, p=2, dim=1)
norm_x2 = torch.norm(x2, p=2, dim=1)
cos_sim = dot_product / (norm_x1 * norm_x2 + self.eps)
loss_pos = 1.0 - cos_sim
loss_neg = F.relu(cos_sim - self.margin)
loss = torch.where(target == 1, loss_pos, loss_neg)
if self.reduction == 'mean':
return loss.mean()
elif self.reduction == 'sum':
return loss.sum()
else:
return loss
class Model(nn.Module):
def __init__(self, margin=0.5):
super().__init__()
self.op = CosineEmbeddingLossCustom(margin=margin, reduction='mean', eps=EPS)
def forward(self, x1: torch.Tensor, x2: torch.Tensor, target: torch.Tensor) -> torch.Tensor:
x1_flat = x1.view(x1.size(0), -1)
x2_flat = x2.view(x2.size(0), -1)
return self.op(x1_flat, x2_flat, target)
def get_inputs():
x1 = torch.randn(N, C, H, W, dtype=torch.float32)
x2 = torch.randn(N, C, H, W, dtype=torch.float32)
target = torch.randint(0, 2, (N,), dtype=torch.float32) # 0 or 1
target = torch.where(target == 0, torch.tensor(-1.0), torch.tensor(1.0))
return [x1, x2, target]
def get_init_inputs():
return [0.5] # margin

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S1/gsd123_#15/run_code.py Normal file
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import torch
import time
from CosineEmbeddingLoss_torch import Model, get_inputs, get_init_inputs
from CosineEmbeddingLoss_cuda import ModelNew
def run_benchmark():
if not torch.cuda.is_available():
print("CUDA 不可用")
return
device = torch.device("cuda")
# 准备输入数据
inputs = [x.cuda(device=device) for x in get_inputs()]
init_inputs = [x.cuda(device=device) if isinstance(x, torch.Tensor) else x for x in get_init_inputs()]
# 初始化模型
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():
# 预热GPU
_ = torch_model(*inputs)
_ = cuda_model(*inputs)
# 正式测试
output_torch = torch_model(*inputs)
output_cuda = cuda_model(*inputs)
# 精度验证
abs_diff = torch.abs(output_torch - output_cuda)
max_diff = torch.max(abs_diff).item()
mean_diff = torch.mean(abs_diff).item()
if max_diff < 1e-4 and mean_diff < 1e-5:
print(f"✅ 精度对齐:最大误差 {max_diff:.6f},平均误差 {mean_diff:.6f}")
precision_flag = True
else:
print(f"❌ 精度不一致:最大误差 {max_diff:.6f},平均误差 {mean_diff:.6f}")
precision_flag = False
print("\n-------------------- 性能加速比测试 --------------------")
num_iterations = 100
# 预热GPU
for _ in range(10):
_ = torch_model(*inputs)
_ = cuda_model(*inputs)
# 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内置Swish平均执行时间: {torch_time:.6f}")
print(f"自定义CUDA Swish平均执行时间: {cuda_time:.6f}")
speedup = torch_time / cuda_time if cuda_time > 0 else 0
print(f"加速比 (Speedup): {speedup:.2f}x")
return precision_flag, speedup
if __name__ == "__main__":
precision_flag, speedup = run_benchmark()