GPUCodeForces/S1/uucoco_#95/logitsigmoidshift_cuda.py

67 lines
1.5 KiB
Python

import torch
import torch.nn as nn
from torch.utils.cpp_extension import load_inline
cuda_source = """
#include <torch/extension.h>
#include <cuda_runtime.h>
__global__ void logit_sigmoid_shift_kernel(
const float* __restrict__ input,
float* __restrict__ output,
float shift,
int size
) {
int idx = blockIdx.x * blockDim.x + threadIdx.x;
if (idx < size) {
float x = input[idx];
float y = logf(x / (1.0f - x));
float z = 1.0f / (1.0f + expf(-y));
output[idx] = z + shift;
}
}
torch::Tensor logit_sigmoid_shift_cuda(torch::Tensor input, float shift) {
auto output = torch::empty_like(input);
int size = input.numel();
const int block_size = 256;
int num_blocks = (size + block_size - 1) / block_size;
logit_sigmoid_shift_kernel<<<num_blocks, block_size>>>(
input.data_ptr<float>(),
output.data_ptr<float>(),
shift,
size
);
return output;
}
"""
cpp_source = """
torch::Tensor logit_sigmoid_shift_cuda(torch::Tensor input, float shift);
"""
module = load_inline(
name="logit_sigmoid_shift",
cpp_sources=cpp_source,
cuda_sources=cuda_source,
functions=["logit_sigmoid_shift_cuda"],
verbose=True
)
class ModelNew(nn.Module):
def __init__(self, shift):
super(ModelNew, self).__init__()
self.shift = shift
self.module = module
def forward(self, x):
return self.module.logit_sigmoid_shift_cuda(x, self.shift)