Files
rust/tests/codegen-llvm
Flakebi 91d4e40e02 Add amdgpu_dispatch_ptr intrinsic
Add a rustc intrinsic `amdgpu_dispatch_ptr` to access the kernel
dispatch packet on amdgpu.
The HSA kernel dispatch packet contains important information like the
launch size and workgroup size.

The Rust intrinsic lowers to the `llvm.amdgcn.dispatch.ptr` LLVM
intrinsic, which returns a `ptr addrspace(4)`, plus an addrspacecast to
`addrspace(0)`, so it can be returned as a Rust reference.

The returned pointer/reference is valid for the whole program lifetime,
and is therefore `'static`.

The return type of the intrinsic (`*const ()`) does not mention the
struct so that rustc does not need to know the exact struct type.
An alternative would be to define the struct as lang item or add a
generic argument to the function.

Short version:
```rust
#[cfg(target_arch = "amdgpu")]
pub fn amdgpu_dispatch_ptr() -> *const ();
```
2026-01-09 10:41:37 +01:00
..
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2025-12-14 20:34:56 +00:00
2025-08-15 16:42:21 +00:00

The files here use the LLVM FileCheck framework, documented at https://llvm.org/docs/CommandGuide/FileCheck.html.

One extension worth noting is the use of revisions as custom prefixes for FileCheck. If your codegen test has different behavior based on the chosen target or different compiler flags that you want to exercise, you can use a revisions annotation, like so:

// revisions: aaa bbb
// [bbb] compile-flags: --flags-for-bbb

After specifying those variations, you can write different expected, or explicitly unexpected output by using <prefix>-SAME: and <prefix>-NOT:, like so:

// CHECK: expected code
// aaa-SAME: emitted-only-for-aaa
// aaa-NOT:                        emitted-only-for-bbb
// bbb-NOT:  emitted-only-for-aaa
// bbb-SAME:                       emitted-only-for-bbb