6912c676cd
Add amdgpu_dispatch_ptr intrinsic There is an ongoing discussion in rust-lang/rust#150452 about using address spaces from the Rust language in some way. As that discussion will likely not conclude soon, this PR adds one rustc_intrinsic with an addrspacecast to unblock getting basic information like launch and workgroup size and make it possible to implement something like `core::gpu`. 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 (`&'static ()`) 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. Is this ok or is there a better way (also, should it return a pointer instead of a reference)? Short version: ```rust #[cfg(target_arch = "amdgpu")] pub fn amdgpu_dispatch_ptr() -> *const (); ``` Tracking issue: rust-lang/rust#135024 |
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| Cargo.toml | ||
| messages.ftl | ||
| README.md | ||
The codegen crate contains the code to convert from MIR into LLVM IR,
and then from LLVM IR into machine code. In general it contains code
that runs towards the end of the compilation process.
For more information about how codegen works, see the rustc dev guide.