GPU Host Module API
baedeker_gpu exposes the baedeker:gpu import ABI as a host module a guest
WASM module can import for explicit GPU compute.
Building and registering
use baedeker_core::runtime::Store;
use baedeker_gpu::GpuHostModule;
fn example(store: &mut Store, reg: &baedeker_core::lower::RegModule, backend: ()) {
// let backend: Box<dyn baedeker_core::runtime::gpu::GpuBackend> = /* ... */;
let backend: Box<dyn baedeker_core::runtime::gpu::GpuBackend> = unimplemented!();
let gpu = GpuHostModule::for_store(backend, store).unwrap();
gpu.register(store, reg).unwrap();
}for_store captures the instance’s linear memory 0 (it fails if the module
declares none). register wires up every baedeker:gpu import the module
declares and silently skips the rest.
The v1 ABI
All imports take i32 operands; handles are non-negative indices. Every
function returns -1 (or a non-positive length for gpu_last_error) on
failure, stashing a diagnostic.
| Import | Signature |
|---|---|
gpu_probe | () -> i32 |
buffer_create | (size) -> handle |
buffer_upload | (mem_offset, len) -> handle |
buffer_read | (handle, buf_offset, mem_offset, len) -> i32 |
kernel_create | (code_ptr, code_len) -> handle |
dispatch | (kernel, wg_x, wg_y, wg_z, tpg_x, tpg_y, tpg_z, bindings_ptr, bindings_len) -> i32 |
gpu_last_error | (mem_offset, max_len) -> bytes_written |
dispatch routes through GpuBackend::dispatch_verified so the explicit
per-workgroup thread count is honoured.
v1 constraints
The backing GpuBackend trait offers whole-buffer upload (on create) and full
readback, but no partial writes or explicit destruction. v1 is therefore
upload-on-create + read-back: upload inputs, allocate an uninitialised output,
dispatch, read the result. Re-uploading mid-computation leaks the prior buffer
until the instance is dropped — a v2 concern once the trait gains a
partial-write method.