std/cuda

March 13, 2026 · View on GitHub

The std/cuda module provides helper functions and types for CUDA interoperability, simplifying memory management, synchronization, and device queries.

Note

This module requires compiling with the --cuda flag.

Usage

import "std/cuda.zc"

fn main() {
    let dev_ptr = cuda_alloc<float>(1024);
    defer cuda_free(dev_ptr);
    
    cuda_sync();
}

Struct Definition

struct CudaDeviceProp {
    name: String;
    total_global_mem: usize;
    multi_processor_count: int;
    major: int;
    minor: int;
    max_threads_per_block: int;
    warp_size: int;
}

Methods

Memory Management

Method	Signature	Description
cuda_alloc	`cuda_alloc<T>(n: usize) -> T*`	Allocates device memory for `n` elements of type `T`.
cuda_free	`cuda_free(ptr: void*)`	Frees device memory.
cuda_copy_to_device	`cuda_copy_to_device(dst: void, src: void, bytes: usize)`	Copies data from host (CPU) to device (GPU).
cuda_copy_to_host	`cuda_copy_to_host(dst: void, src: void, bytes: usize)`	Copies data from device (GPU) to host (CPU).
cuda_copy_device	`cuda_copy_device(dst: void, src: void, bytes: usize)`	Copies data from device to device.
cuda_zero	`cuda_zero(ptr: void*, bytes: usize)`	Sets device memory to zero.

Synchronization

Method	Signature	Description
cuda_sync	`cuda_sync()`	Synchronizes the device (blocks until all previous CUDA calls complete).

Device Information

Method	Signature	Description
cuda_device_count	`cuda_device_count() -> int`	Returns the number of available CUDA devices.
cuda_set_device	`cuda_set_device(id: int)`	Sets the active CUDA device.
cuda_device_properties	`cuda_device_properties(device_id: int) -> CudaDeviceProp`	Returns properties of the specified device.

Device Functions (Kernel Only)

These functions are marked @device and should only be called from within a kernel (@global) or device functions.

Function	Signature	Description
thread_id	`thread_id() -> int`	Global thread index.
block_id	`block_id() -> int`	Block index (`blockIdx.x`).
local_id	`local_id() -> int`	Local thread index (`threadIdx.x`).
block_size	`block_size() -> int`	Block dimension (`blockDim.x`).
grid_size	`grid_size() -> int`	Grid dimension (`gridDim.x`).