| commit | 15482c83aa2b05779d7ad947c34835656ab9da1c | [log] [tgz] |
|---|---|---|
| author | Shilei Tian <i@tianshilei.me> | Tue Jun 17 19:58:24 2025 -0400 |
| committer | GitHub <noreply@github.com> | Tue Jun 17 19:58:24 2025 -0400 |
| tree | dc8dab56691ff2af5199cd4dd1886c583c92fc9f | |
| parent | c21a4c6c43bb6d68dfe52e07a5a391a6167eedf9 [diff] |
[ElimAvailExtern] Add an option to allow to convert global variables in a specified address space to local (#144287) Currently, the `EliminateAvailableExternallyPass` only converts certain available externally functions to local if `avail-extern-to-local` is set or in contextual profiling mode. For global variables, it only drops their initializers. This PR adds an option to allow the pass to convert global variables in a specified address space to local. The motivation for this change is to correctly support lowering of LDS variables (`__shared__` variables, in more generic terminology) when ThinLTO is enabled for AMDGPU. A `__shared__` variable is lowered to a hidden global variable in a particular address space by the frontend, which is roughly same as a `static` local variable. To properly lower it in the backend, the compiler needs to check all its uses. Enabling ThinLTO currently breaks this when a function containing a `__shared__` variable is imported from another module. Even though the global variable is imported along with its associated function, and the function is privatized by the `EliminateAvailableExternallyPass`, the global variable itself is not. It's safe to privatize such global variables, because they're _local_ to their associated functions. If the function itself is privatized, its associated global variables should also be privatized accordingly.
Welcome to the LLVM project!
This repository contains the source code for LLVM, a toolkit for the construction of highly optimized compilers, optimizers, and run-time environments.
The LLVM project has multiple components. The core of the project is itself called “LLVM”. This contains all of the tools, libraries, and header files needed to process intermediate representations and convert them into object files. Tools include an assembler, disassembler, bitcode analyzer, and bitcode optimizer.
C-like languages use the Clang frontend. This component compiles C, C++, Objective-C, and Objective-C++ code into LLVM bitcode -- and from there into object files, using LLVM.
Other components include: the libc++ C++ standard library, the LLD linker, and more.
Consult the Getting Started with LLVM page for information on building and running LLVM.
For information on how to contribute to the LLVM project, please take a look at the Contributing to LLVM guide.
Join the LLVM Discourse forums, Discord chat, LLVM Office Hours or Regular sync-ups.
The LLVM project has adopted a code of conduct for participants to all modes of communication within the project.