3 Commits

Author SHA1 Message Date
Joseph Huber
6bd4d717d5 [libc] Add environment variables to GPU libc test for AMDGPU
This patch performs the same operation to copy over the `argv` array to
the `envp` array. This allows the GPU tests to use environment
variables.

Reviewed By: sivachandra

Differential Revision: https://reviews.llvm.org/D146322
2023-03-20 13:16:58 -05:00
Joseph Huber
8e4f9b1fcb [libc] Add initial support for an RPC mechanism for the GPU
This patch adds initial support for an RPC client / server architecture.
The GPU is unable to perform several system utilities on its own, so in
order to implement features like printing or memory allocation we need
to be able to communicate with the executing process. This is done via a
buffer of "sharable" memory. That is, a buffer with a unified pointer
that both the client and server can use to communicate.

The implementation here is based off of Jon Chesterfields minimal RPC
example in his work. We use an `inbox` and `outbox` to communicate
between if there is an RPC request and to signify when work is done.
We use a fixed-size buffer for the communication channel. This is fixed
size so that we can ensure that there is enough space for all
compute-units on the GPU to issue work to any of the ports. Right now
the implementation is single threaded so there is only a single buffer
that is not shared.

This implementation still has several features missing to be complete.
Such as multi-threaded support and asynchrnonous calls.

Depends on D145912

Reviewed By: sivachandra

Differential Revision: https://reviews.llvm.org/D145913
2023-03-17 12:55:31 -05:00
Joseph Huber
fa34b9e032 [libc] Add startup code implementation for GPU targets
This patch introduces startup code for executing `main` on a device
compiled for the GPU. We will primarily use this to run standalone
integration tests on the GPU. The actual execution of this routine will
need to be provided by a `loader` utility to bootstrap execution on the
GPU.

Reviewed By: sivachandra

Differential Revision: https://reviews.llvm.org/D143212
2023-02-07 11:36:16 -06:00