Vulkan API

#include "aicraft/vulkan.h"

Overview

Optional Vulkan compute backend for GPU-accelerated operations. Link with -lvulkan to enable.

Initialisation

ac_vulkan_init();                  // Auto-select best GPU
ac_vulkan_select_device(int idx);  // Select specific GPU
ac_vulkan_shutdown();              // Release GPU resources

Device Info

typedef struct AcVkDeviceInfo {
    char  name[256];
    int   vram_mb;
    int   compute_units;
    int   max_workgroup_size;
} AcVkDeviceInfo;

AcVkDeviceInfo info = ac_vulkan_device_info();

Data Transfer

void ac_vulkan_upload(AcTensor *t);     // CPU → GPU
void ac_vulkan_download(AcTensor *t);   // GPU → CPU
void ac_vulkan_sync();                   // Wait for GPU

Compute Shaders

14 GLSL compute shaders are compiled at initialisation:

Shader	Operation
gemm.comp	General matrix multiply
relu.comp	ReLU activation
sigmoid.comp	Sigmoid activation
softmax.comp	Softmax
add.comp	Element-wise add
mul.comp	Element-wise mul
reduce_sum.comp	Sum reduction
reduce_max.comp	Max reduction
transpose.comp	Matrix transpose
cross_entropy.comp	CE loss
mse.comp	MSE loss
adam_step.comp	Adam update
quantize.comp	INT8 quantisation
broadcast.comp	Broadcasting

Backend Dispatch

When Vulkan is initialised, operations on uploaded tensors automatically dispatch to GPU shaders. No code changes needed:

ac_vulkan_init();
ac_vulkan_upload(x);

// This runs on GPU automatically
AcTensor *y = ac_forward_seq(net, 2, x);

ac_vulkan_download(y);

Fallback

If Vulkan initialisation fails (e.g., no GPU), operations fall back to the CPU (SIMD) backend transparently.