Merge pull request 'finish Polar-affine #95' (#496) from gsd123/GPUCodeForces:gsd95 into main

This commit is contained in:
wawahejun 2025-12-14 22:46:16 +08:00
commit 2fbdc45028
4 changed files with 317 additions and 0 deletions

View File

@ -0,0 +1,125 @@
import torch
import torch.nn as nn
from torch.utils.cpp_extension import load_inline
class ModelNew(nn.Module):
def __init__(self, num_features=512):
super().__init__()
assert num_features % 2 == 0
self.num_features = num_features
self.weight_r = nn.Parameter(torch.ones(num_features // 2))
self.bias_r = nn.Parameter(torch.zeros(num_features // 2))
self.weight_theta = nn.Parameter(torch.ones(num_features // 2))
self.bias_theta = nn.Parameter(torch.zeros(num_features // 2))
self._compile_cuda_kernel()
def _compile_cuda_kernel(self):
cpp_source = """
torch::Tensor polaraffine_cuda(
torch::Tensor x,
torch::Tensor weight_r,
torch::Tensor bias_r,
torch::Tensor weight_theta,
torch::Tensor bias_theta);
"""
cuda_source = """
#include <torch/extension.h>
#include <cuda_runtime.h>
#include <math.h>
__global__ void polaraffine_kernel(
const float* __restrict__ x,
const float* __restrict__ weight_r,
const float* __restrict__ bias_r,
const float* __restrict__ weight_theta,
const float* __restrict__ bias_theta,
float* __restrict__ output,
const int rows,
const int cols)
{
const int n_pairs = cols / 2;
const int tid = blockIdx.x * blockDim.x + threadIdx.x;
const int stride = blockDim.x * gridDim.x;
const int total_pairs = rows * n_pairs;
for (int i = tid; i < total_pairs; i += stride) {
const int r_idx = i / n_pairs;
const int p_idx = i % n_pairs;
const int idx_even = r_idx * cols + 2 * p_idx;
const int idx_odd = r_idx * cols + 2 * p_idx + 1;
float x_ev = x[idx_even];
float x_od = x[idx_odd];
float r = hypotf(x_ev, x_od);
float theta = atan2f(x_od, x_ev);
float w_r = weight_r[p_idx];
float b_r = bias_r[p_idx];
float w_th = weight_theta[p_idx];
float b_th = bias_theta[p_idx];
float r_new = __fadd_rn(__fmul_rn(r, w_r), b_r);
float theta_new = __fadd_rn(__fmul_rn(theta, w_th), b_th);
float c = cosf(theta_new);
float s = sinf(theta_new);
output[idx_even] = __fmul_rn(r_new, c);
output[idx_odd] = __fmul_rn(r_new, s);
}
}
torch::Tensor polaraffine_cuda(
torch::Tensor x,
torch::Tensor weight_r,
torch::Tensor bias_r,
torch::Tensor weight_theta,
torch::Tensor bias_theta)
{
auto x_c = x.contiguous();
auto wr_c = weight_r.contiguous();
auto br_c = bias_r.contiguous();
auto wth_c = weight_theta.contiguous();
auto bth_c = bias_theta.contiguous();
const int rows = x_c.size(0);
const int cols = x_c.size(1);
auto output = torch::empty_like(x_c);
const int total_pairs = rows * (cols / 2);
const int threads = 256;
const int blocks = min((total_pairs + threads - 1) / threads, 65535);
polaraffine_kernel<<<blocks, threads>>>(
x_c.data_ptr<float>(),
wr_c.data_ptr<float>(),
br_c.data_ptr<float>(),
wth_c.data_ptr<float>(),
bth_c.data_ptr<float>(),
output.data_ptr<float>(),
rows,
cols
);
return output;
}
"""
self.op = load_inline(
name="polaraffine_op",
cpp_sources=cpp_source,
cuda_sources=cuda_source,
functions=["polaraffine_cuda"],
extra_cuda_cflags=["-O3", "-fmad=false"],
verbose=False
)
def forward(self, x):
return self.op.polaraffine_cuda(
x, self.weight_r, self.bias_r, self.weight_theta, self.bias_theta
)

View File

@ -0,0 +1,44 @@
import torch
import torch.nn as nn
class Model(nn.Module):
def __init__(self, num_features=512):
super().__init__()
assert num_features % 2 == 0
self.num_features = num_features
self.weight_r = nn.Parameter(torch.ones(num_features // 2))
self.bias_r = nn.Parameter(torch.zeros(num_features // 2))
self.weight_theta = nn.Parameter(torch.ones(num_features // 2))
self.bias_theta = nn.Parameter(torch.zeros(num_features // 2))
def forward(self, x: torch.Tensor) -> torch.Tensor:
x_even = x[:, 0::2]
x_odd = x[:, 1::2]
r = torch.hypot(x_even, x_odd)
theta = torch.atan2(x_odd, x_even)
r_new = r * self.weight_r + self.bias_r
theta_new = theta * self.weight_theta + self.bias_theta
x_even_new = r_new * torch.cos(theta_new)
x_odd_new = r_new * torch.sin(theta_new)
y = torch.empty_like(x)
y[:, 0::2] = x_even_new
y[:, 1::2] = x_odd_new
return y
batch_size = 128
feature_dim = 512
def get_inputs():
x = torch.randn(batch_size, feature_dim, dtype=torch.float32)
return [x]
def get_init_inputs():
return []

71
S1/gsd123_#95/prompt.txt Normal file
View File

@ -0,0 +1,71 @@
You write custom CUDA kernels to replace the pytorch operators in the given GeGLU 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 chunk+gelu+elementwise_mul), or algorithmic changes (such as optimized memory access patterns). You are only limited by your imagination.
Custom CUDA kernel extension via torch.utils.cpp_extension.load_inline
Polar coordinate transformation: (x,y) ↔ (r,θ) with learnable affine transforms
Element-wise parallelization using CUDA grid-stride loops over feature pairs
Per-feature-pair learnable parameters for radius and angle (weight_r, bias_r, weight_θ, bias_θ)
Contiguous tensor handling for all input tensors
Memory-efficient in-place-like computation with torch.empty_like
Mathematical operations: hypotf, atan2f, cosf, sinf
Fused multiply-add with __fmul_rn and __fadd_rn for precision control
Auto-tuning block/grid size based on number of feature pairs
Even-odd feature pairing for polar coordinate processing
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
class Model(nn.Module):
def __init__(self, num_features=512):
super().__init__()
assert num_features % 2 == 0
self.num_features = num_features
self.weight_r = nn.Parameter(torch.ones(num_features // 2))
self.bias_r = nn.Parameter(torch.zeros(num_features // 2))
self.weight_theta = nn.Parameter(torch.ones(num_features // 2))
self.bias_theta = nn.Parameter(torch.zeros(num_features // 2))
def forward(self, x: torch.Tensor) -> torch.Tensor:
x_even = x[:, 0::2]
x_odd = x[:, 1::2]
r = torch.hypot(x_even, x_odd)
theta = torch.atan2(x_odd, x_even)
r_new = r * self.weight_r + self.bias_r
theta_new = theta * self.weight_theta + self.bias_theta
x_even_new = r_new * torch.cos(theta_new)
x_odd_new = r_new * torch.sin(theta_new)
y = torch.empty_like(x)
y[:, 0::2] = x_even_new
y[:, 1::2] = x_odd_new
return y
batch_size = 128
feature_dim = 512
def get_inputs():
x = torch.randn(batch_size, feature_dim, dtype=torch.float32)
return [x]
def get_init_inputs():
return []

77
S1/gsd123_#95/run_code.py Normal file
View File

@ -0,0 +1,77 @@
###########################################################
# 性能和精度验证程序
###########################################################
import torch
import torch.nn as nn
import time
from polaraffine_torch import Model, get_inputs, get_init_inputs
from polaraffine_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()