use super::{ActivationFunction, NeuralResult, NeuralIntegrationError};
pub struct OptimizedKernels;
impl OptimizedKernels {
pub fn matrix_multiply_kernel(rows_a: usize, cols_a: usize, cols_b: usize) -> &'static str {
r#"
extern "C" __global__ void optimized_matrix_multiply(
const float* __restrict__ A,
const float* __restrict__ B,
float* __restrict__ C,
int M, int N, int K
) {
// Shared memory for tiling
__shared__ float As[32][32];
__shared__ float Bs[32][32];
int bx = blockIdx.x, by = blockIdx.y;
int tx = threadIdx.x, ty = threadIdx.y;
// Calculate global position
int row = by * 32 + ty;
int col = bx * 32 + tx;
float sum = 0.0f;
// Loop over tiles
for (int t = 0; t < (K + 31) / 32; ++t) {
// Load tiles into shared memory
int a_col = t * 32 + tx;
int b_row = t * 32 + ty;
if (row < M && a_col < K) {
As[ty][tx] = A[row * K + a_col];
} else {
As[ty][tx] = 0.0f;
}
if (b_row < K && col < N) {
Bs[ty][tx] = B[b_row * N + col];
} else {
Bs[ty][tx] = 0.0f;
}
__syncthreads();
// Compute partial sum using shared memory
#pragma unroll 32
for (int k = 0; k < 32; ++k) {
sum += As[ty][k] * Bs[k][tx];
}
__syncthreads();
}
// Write result
if (row < M && col < N) {
C[row * N + col] = sum;
}
}
"#
}
pub fn vector_operations_kernel() -> &'static str {
r#"
extern "C" __global__ void optimized_vector_add(
const float* __restrict__ a,
const float* __restrict__ b,
float* __restrict__ result,
int size
) {
int idx = blockIdx.x * blockDim.x + threadIdx.x;
int stride = blockDim.x * gridDim.x;
// Grid-stride loop for better memory coalescing
for (int i = idx; i < size; i += stride) {
result[i] = a[i] + b[i];
}
}
extern "C" __global__ void optimized_vector_multiply(
const float* __restrict__ a,
const float* __restrict__ b,
float* __restrict__ result,
int size
) {
int idx = blockIdx.x * blockDim.x + threadIdx.x;
int stride = blockDim.x * gridDim.x;
for (int i = idx; i < size; i += stride) {
result[i] = a[i] * b[i];
}
}
extern "C" __global__ void optimized_vector_scale(
const float* __restrict__ input,
float scale,
float* __restrict__ result,
int size
) {
int idx = blockIdx.x * blockDim.x + threadIdx.x;
int stride = blockDim.x * gridDim.x;
for (int i = idx; i < size; i += stride) {
result[i] = input[i] * scale;
}
}
"#
}
pub fn activation_functions_kernel() -> &'static str {
r#"
// Fast approximation functions
__device__ __forceinline__ float fast_sigmoid(float x) {
return 1.0f / (1.0f + expf(-x));
}
__device__ __forceinline__ float fast_tanh(float x) {
// Fast tanh approximation using polynomial
float x2 = x * x;
float a = x * (135135.0f + x2 * (17325.0f + x2 * (378.0f + x2)));
float b = 135135.0f + x2 * (62370.0f + x2 * (3150.0f + x2 * 28.0f));
return a / b;
}
__device__ __forceinline__ float fast_gelu(float x) {
// Fast GELU approximation
return 0.5f * x * (1.0f + fast_tanh(0.7978845608f * (x + 0.044715f * x * x * x)));
}
extern "C" __global__ void optimized_activation_functions(
const float* __restrict__ input,
float* __restrict__ output,
int size,
int activation_type
) {
int idx = blockIdx.x * blockDim.x + threadIdx.x;
int stride = blockDim.x * gridDim.x;
for (int i = idx; i < size; i += stride) {
float x = input[i];
float result;
switch (activation_type) {
case 0: // Sigmoid
result = fast_sigmoid(x);
break;
case 1: // ReLU
result = fmaxf(0.0f, x);
break;
case 2: // Tanh
result = fast_tanh(x);
break;
case 3: // Leaky ReLU
result = x > 0.0f ? x : 0.01f * x;
break;
case 4: // Swish
result = x * fast_sigmoid(x);
break;
case 5: // GELU
result = fast_gelu(x);
break;
default:
result = x; // Linear
}
output[i] = result;
}
}
extern "C" __global__ void optimized_activation_derivatives(
const float* __restrict__ input,
float* __restrict__ output,
int size,
int activation_type
) {
int idx = blockIdx.x * blockDim.x + threadIdx.x;
int stride = blockDim.x * gridDim.x;
for (int i = idx; i < size; i += stride) {
float x = input[i];
float result;
switch (activation_type) {
case 0: { // Sigmoid derivative
float s = fast_sigmoid(x);
result = s * (1.0f - s);
break;
}
case 1: // ReLU derivative
result = x > 0.0f ? 1.0f : 0.0f;
break;
case 2: { // Tanh derivative
float t = fast_tanh(x);
result = 1.0f - t * t;
break;
}
case 3: // Leaky ReLU derivative
result = x > 0.0f ? 1.0f : 0.01f;
break;
case 4: { // Swish derivative
float s = fast_sigmoid(x);
result = s + x * s * (1.0f - s);
break;
}
case 5: { // GELU derivative (approximation)
float tanh_arg = 0.7978845608f * (x + 0.044715f * x * x * x);
float tanh_val = fast_tanh(tanh_arg);
result = 0.5f * (1.0f + tanh_val) + x * 0.5f * (1.0f - tanh_val * tanh_val) *
0.7978845608f * (1.0f + 3.0f * 0.044715f * x * x);
break;
}
default:
result = 1.0f; // Linear derivative
}
output[i] = result;
}
}
"#
}
pub fn convolution_kernel() -> &'static str {
r#"
extern "C" __global__ void optimized_conv2d(
const float* __restrict__ input,
const float* __restrict__ kernel,
float* __restrict__ output,
int batch_size,
int in_channels,
int out_channels,
int in_height,
int in_width,
int kernel_size,
int stride,
int padding
) {
// Shared memory for input tile
extern __shared__ float shared_input[];
int batch = blockIdx.z;
int out_channel = blockIdx.y;
int out_x = blockIdx.x * blockDim.x + threadIdx.x;
int out_y = threadIdx.y;
int out_height = (in_height + 2 * padding - kernel_size) / stride + 1;
int out_width = (in_width + 2 * padding - kernel_size) / stride + 1;
if (out_x >= out_width || out_y >= out_height) return;
float sum = 0.0f;
for (int in_channel = 0; in_channel < in_channels; ++in_channel) {
for (int ky = 0; ky < kernel_size; ++ky) {
for (int kx = 0; kx < kernel_size; ++kx) {
int in_y = out_y * stride - padding + ky;
int in_x = out_x * stride - padding + kx;
if (in_y >= 0 && in_y < in_height && in_x >= 0 && in_x < in_width) {
int input_idx = batch * in_channels * in_height * in_width +
in_channel * in_height * in_width +
in_y * in_width + in_x;
int kernel_idx = out_channel * in_channels * kernel_size * kernel_size +
in_channel * kernel_size * kernel_size +
ky * kernel_size + kx;
sum += input[input_idx] * kernel[kernel_idx];
}
}
}
}
int output_idx = batch * out_channels * out_height * out_width +
out_channel * out_height * out_width +
out_y * out_width + out_x;
output[output_idx] = sum;
}
"#
}
pub fn forward_propagation_kernel() -> &'static str {
r#"
extern "C" __global__ void optimized_forward_propagation(
const float* __restrict__ input,
const float* __restrict__ weights,
const float* __restrict__ biases,
float* __restrict__ output,
int batch_size,
int input_size,
int output_size,
int activation_type
) {
// Shared memory for weight tiles
__shared__ float weight_tile[32][32];
__shared__ float input_tile[32];
int batch = blockIdx.z;
int output_neuron = blockIdx.y * blockDim.y + threadIdx.y;
int tx = threadIdx.x;
int ty = threadIdx.y;
if (output_neuron >= output_size) return;
float sum = 0.0f;
// Process input in tiles
for (int tile = 0; tile < (input_size + 31) / 32; ++tile) {
int input_idx = tile * 32 + tx;
// Load input tile
if (input_idx < input_size && ty == 0) {
input_tile[tx] = input[batch * input_size + input_idx];
} else if (ty == 0) {
input_tile[tx] = 0.0f;
}
// Load weight tile
if (input_idx < input_size) {
weight_tile[ty][tx] = weights[output_neuron * input_size + input_idx];
} else {
weight_tile[ty][tx] = 0.0f;
}
__syncthreads();
// Compute partial sum
#pragma unroll 32
for (int k = 0; k < 32; ++k) {
sum += weight_tile[ty][k] * input_tile[k];
}
__syncthreads();
}
// Add bias
sum += biases[output_neuron];
// Apply activation function
float result;
switch (activation_type) {
case 0: // Sigmoid
result = 1.0f / (1.0f + expf(-sum));
break;
case 1: // ReLU
result = fmaxf(0.0f, sum);
break;
case 2: // Tanh
result = tanhf(sum);
break;
default:
result = sum; // Linear
}
output[batch * output_size + output_neuron] = result;
}
"#
}
pub fn backward_propagation_kernel() -> &'static str {
r#"
extern "C" __global__ void optimized_backward_propagation(
const float* __restrict__ delta_output,
const float* __restrict__ weights,
const float* __restrict__ activations,
float* __restrict__ delta_input,
float* __restrict__ weight_gradients,
float* __restrict__ bias_gradients,
int batch_size,
int input_size,
int output_size,
int activation_type
) {
__shared__ float delta_shared[32];
__shared__ float activation_shared[32];
int batch = blockIdx.z;
int input_neuron = blockIdx.x * blockDim.x + threadIdx.x;
int tx = threadIdx.x;
if (input_neuron >= input_size) return;
float delta_sum = 0.0f;
// Process output deltas in tiles
for (int tile = 0; tile < (output_size + 31) / 32; ++tile) {
int output_idx = tile * 32 + tx;
// Load delta tile
if (output_idx < output_size) {
delta_shared[tx] = delta_output[batch * output_size + output_idx];
} else {
delta_shared[tx] = 0.0f;
}
__syncthreads();
// Compute delta contribution
#pragma unroll 32
for (int k = 0; k < 32; ++k) {
int out_neuron = tile * 32 + k;
if (out_neuron < output_size) {
delta_sum += delta_shared[k] * weights[out_neuron * input_size + input_neuron];
}
}
__syncthreads();
}
// Apply activation derivative
float activation = activations[batch * input_size + input_neuron];
float derivative;
switch (activation_type) {
case 0: // Sigmoid derivative
derivative = activation * (1.0f - activation);
break;
case 1: // ReLU derivative
derivative = activation > 0.0f ? 1.0f : 0.0f;
break;
case 2: // Tanh derivative
derivative = 1.0f - activation * activation;
break;
default:
derivative = 1.0f; // Linear derivative
}
delta_input[batch * input_size + input_neuron] = delta_sum * derivative;
}
extern "C" __global__ void optimized_compute_gradients(
const float* __restrict__ delta_output,
const float* __restrict__ input_activations,
float* __restrict__ weight_gradients,
float* __restrict__ bias_gradients,
int batch_size,
int input_size,
int output_size,
float learning_rate
) {
int input_neuron = blockIdx.x * blockDim.x + threadIdx.x;
int output_neuron = blockIdx.y * blockDim.y + threadIdx.y;
if (input_neuron >= input_size || output_neuron >= output_size) return;
float gradient_sum = 0.0f;
// Accumulate gradients across batch
for (int batch = 0; batch < batch_size; ++batch) {
float delta = delta_output[batch * output_size + output_neuron];
float activation = input_activations[batch * input_size + input_neuron];
gradient_sum += delta * activation;
}
// Update weight gradient
int weight_idx = output_neuron * input_size + input_neuron;
weight_gradients[weight_idx] = gradient_sum / batch_size;
// Update bias gradient (only for first input neuron to avoid race conditions)
if (input_neuron == 0) {
float bias_gradient = 0.0f;
for (int batch = 0; batch < batch_size; ++batch) {
bias_gradient += delta_output[batch * output_size + output_neuron];
}
bias_gradients[output_neuron] = bias_gradient / batch_size;
}
}
"#
}
pub fn reduction_operations_kernel() -> &'static str {
r#"
extern "C" __global__ void optimized_reduce_sum(
const float* __restrict__ input,
float* __restrict__ output,
int size
) {
__shared__ float sdata[256];
int tid = threadIdx.x;
int i = blockIdx.x * blockDim.x + threadIdx.x;
// Load data into shared memory
sdata[tid] = (i < size) ? input[i] : 0.0f;
__syncthreads();
// Reduction in shared memory
for (int s = blockDim.x / 2; s > 0; s >>= 1) {
if (tid < s) {
sdata[tid] += sdata[tid + s];
}
__syncthreads();
}
// Write result for this block
if (tid == 0) {
output[blockIdx.x] = sdata[0];
}
}
extern "C" __global__ void optimized_reduce_max(
const float* __restrict__ input,
float* __restrict__ output,
int size
) {
__shared__ float sdata[256];
int tid = threadIdx.x;
int i = blockIdx.x * blockDim.x + threadIdx.x;
// Load data into shared memory
sdata[tid] = (i < size) ? input[i] : -INFINITY;
__syncthreads();
// Reduction in shared memory
for (int s = blockDim.x / 2; s > 0; s >>= 1) {
if (tid < s) {
sdata[tid] = fmaxf(sdata[tid], sdata[tid + s]);
}
__syncthreads();
}
// Write result for this block
if (tid == 0) {
output[blockIdx.x] = sdata[0];
}
}
extern "C" __global__ void optimized_softmax(
const float* __restrict__ input,
float* __restrict__ output,
int batch_size,
int size
) {
__shared__ float max_val;
__shared__ float sum_exp;
int batch = blockIdx.x;
int tid = threadIdx.x;
if (batch >= batch_size) return;
const float* batch_input = input + batch * size;
float* batch_output = output + batch * size;
// Find maximum value
float local_max = -INFINITY;
for (int i = tid; i < size; i += blockDim.x) {
local_max = fmaxf(local_max, batch_input[i]);
}
// Reduce maximum across threads
local_max = blockReduceMax(local_max);
if (tid == 0) max_val = local_max;
__syncthreads();
// Compute sum of exponentials
float local_sum = 0.0f;
for (int i = tid; i < size; i += blockDim.x) {
local_sum += expf(batch_input[i] - max_val);
}
// Reduce sum across threads
local_sum = blockReduceSum(local_sum);
if (tid == 0) sum_exp = local_sum;
__syncthreads();
// Compute softmax
for (int i = tid; i < size; i += blockDim.x) {
batch_output[i] = expf(batch_input[i] - max_val) / sum_exp;
}
}
__device__ float blockReduceSum(float val) {
static __shared__ float shared[32];
int lane = threadIdx.x % 32;
int wid = threadIdx.x / 32;
val = warpReduceSum(val);
if (lane == 0) shared[wid] = val;
__syncthreads();
val = (threadIdx.x < blockDim.x / 32) ? shared[lane] : 0;
if (wid == 0) val = warpReduceSum(val);
return val;
}
__device__ float blockReduceMax(float val) {
static __shared__ float shared[32];
int lane = threadIdx.x % 32;
int wid = threadIdx.x / 32;
val = warpReduceMax(val);
if (lane == 0) shared[wid] = val;
__syncthreads();
val = (threadIdx.x < blockDim.x / 32) ? shared[lane] : -INFINITY;
if (wid == 0) val = warpReduceMax(val);
return val;
}
__device__ float warpReduceSum(float val) {
for (int offset = 16; offset > 0; offset /= 2) {
val += __shfl_down_sync(0xFFFFFFFF, val, offset);
}
return val;
}
__device__ float warpReduceMax(float val) {
for (int offset = 16; offset > 0; offset /= 2) {
val = fmaxf(val, __shfl_down_sync(0xFFFFFFFF, val, offset));
}
return val;
}
"#
}
pub fn get_activation_kernel(function: ActivationFunction) -> NeuralResult<String> {
let activation_code = match function {
ActivationFunction::Sigmoid => "fast_sigmoid(x)",
ActivationFunction::ReLU => "fmaxf(0.0f, x)",
ActivationFunction::Tanh => "fast_tanh(x)",
ActivationFunction::LeakyReLU => "x > 0.0f ? x : 0.01f * x",
ActivationFunction::Swish => "x * fast_sigmoid(x)",
ActivationFunction::GELU => "fast_gelu(x)",
};
let kernel = format!(r#"
{}
extern "C" __global__ void specialized_activation(
const float* __restrict__ input,
float* __restrict__ output,
int size
) {{
int idx = blockIdx.x * blockDim.x + threadIdx.x;
int stride = blockDim.x * gridDim.x;
for (int i = idx; i < size; i += stride) {{
float x = input[i];
output[i] = {};
}}
}}
"#, Self::activation_functions_kernel(), activation_code);
Ok(kernel)
}
pub fn get_combined_kernels() -> &'static str {
r#"
// Combined optimized kernels for neural operations
#include <cuda_runtime.h>
#include <device_launch_parameters.h>
#include <cmath>
// Fast math approximations
__device__ __forceinline__ float fast_sigmoid(float x) {
return 1.0f / (1.0f + expf(-x));
}
__device__ __forceinline__ float fast_tanh(float x) {
float x2 = x * x;
float a = x * (135135.0f + x2 * (17325.0f + x2 * (378.0f + x2)));
float b = 135135.0f + x2 * (62370.0f + x2 * (3150.0f + x2 * 28.0f));
return a / b;
}
__device__ __forceinline__ float fast_gelu(float x) {
return 0.5f * x * (1.0f + fast_tanh(0.7978845608f * (x + 0.044715f * x * x * x)));
}
// Warp-level reductions
__device__ float warpReduceSum(float val) {
for (int offset = 16; offset > 0; offset /= 2) {
val += __shfl_down_sync(0xFFFFFFFF, val, offset);
}
return val;
}
__device__ float warpReduceMax(float val) {
for (int offset = 16; offset > 0; offset /= 2) {
val = fmaxf(val, __shfl_down_sync(0xFFFFFFFF, val, offset));
}
return val;
}
// Block-level reductions
__device__ float blockReduceSum(float val) {
static __shared__ float shared[32];
int lane = threadIdx.x % 32;
int wid = threadIdx.x / 32;
val = warpReduceSum(val);
if (lane == 0) shared[wid] = val;
__syncthreads();
val = (threadIdx.x < blockDim.x / 32) ? shared[lane] : 0;
if (wid == 0) val = warpReduceSum(val);
return val;
}
__device__ float blockReduceMax(float val) {
static __shared__ float shared[32];
int lane = threadIdx.x % 32;
int wid = threadIdx.x / 32;
val = warpReduceMax(val);
if (lane == 0) shared[wid] = val;
__syncthreads();
val = (threadIdx.x < blockDim.x / 32) ? shared[lane] : -INFINITY;
if (wid == 0) val = warpReduceMax(val);
return val;
}
// Include all optimized kernels
// Matrix operations
extern "C" __global__ void optimized_matrix_multiply(...);
// Vector operations
extern "C" __global__ void optimized_vector_add(...);
extern "C" __global__ void optimized_vector_multiply(...);
extern "C" __global__ void optimized_vector_scale(...);
// Activation functions
extern "C" __global__ void optimized_activation_functions(...);
extern "C" __global__ void optimized_activation_derivatives(...);
// Neural network layers
extern "C" __global__ void optimized_forward_propagation(...);
extern "C" __global__ void optimized_backward_propagation(...);
extern "C" __global__ void optimized_compute_gradients(...);
// Convolution
extern "C" __global__ void optimized_conv2d(...);
// Reductions
extern "C" __global__ void optimized_reduce_sum(...);
extern "C" __global__ void optimized_reduce_max(...);
extern "C" __global__ void optimized_softmax(...);
"#
}
}
#[derive(Debug, Clone)]
pub struct KernelConfig {
pub block_size: (u32, u32, u32),
pub grid_size: (u32, u32, u32),
pub shared_memory_size: u32,
}
impl KernelConfig {
pub fn for_matrix_multiply(rows: usize, cols: usize) -> Self {
let block_x = 32u32;
let block_y = 32u32;
let grid_x = (cols as u32).div_ceil(block_x);
let grid_y = (rows as u32).div_ceil(block_y);
Self {
block_size: (block_x, block_y, 1),
grid_size: (grid_x, grid_y, 1),
shared_memory_size: block_x * block_y * 4 * 2, }
}
pub fn for_vector_operation(size: usize) -> Self {
let block_size = 256u32;
let grid_size = (size as u32).div_ceil(block_size);
Self {
block_size: (block_size, 1, 1),
grid_size: (grid_size, 1, 1),
shared_memory_size: 0,
}
}
pub fn for_convolution(batch_size: usize, out_channels: usize, out_height: usize, out_width: usize) -> Self {
let block_x = 16u32;
let block_y = 16u32;
let grid_x = (out_width as u32).div_ceil(block_x);
let grid_y = (out_channels as u32).div_ceil(block_y);
let grid_z = batch_size as u32;
Self {
block_size: (block_x, block_y, 1),
grid_size: (grid_x, grid_y, grid_z),
shared_memory_size: block_x * block_y * 4, }
}
}
#[derive(Debug, Clone)]
pub struct LaunchParams {
pub config: KernelConfig,
pub stream: Option<u64>, }
impl LaunchParams {
pub fn new(config: KernelConfig) -> Self {
Self {
config,
stream: None,
}
}
pub fn with_stream(mut self, stream: u64) -> Self {
self.stream = Some(stream);
self
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_kernel_availability() {
let matrix_kernel = OptimizedKernels::matrix_multiply_kernel(4, 4, 4);
assert!(matrix_kernel.contains("optimized_matrix_multiply"));
assert!(matrix_kernel.contains("__shared__"));
}
#[test]
fn test_vector_kernels() {
let vector_kernel = OptimizedKernels::vector_operations_kernel();
assert!(vector_kernel.contains("optimized_vector_add"));
assert!(vector_kernel.contains("Grid-stride loop"));
}
#[test]
fn test_activation_kernels() {
let activation_kernel = OptimizedKernels::activation_functions_kernel();
assert!(activation_kernel.contains("fast_sigmoid"));
assert!(activation_kernel.contains("fast_gelu"));
}
#[test]
fn test_kernel_config() {
let config = KernelConfig::for_matrix_multiply(128, 128);
assert_eq!(config.block_size, (32, 32, 1));
assert_eq!(config.grid_size, (4, 4, 1));
}
#[test]
fn test_activation_kernel_generation() {
let kernel = OptimizedKernels::get_activation_kernel(ActivationFunction::ReLU).unwrap();
assert!(kernel.contains("fmaxf"));
assert!(kernel.contains("specialized_activation"));
}
}