ee73f80dc9
Enable ThinLTO with incremental compilation. This is an updated version of #52309. This PR allows `rustc` to use (local) ThinLTO and incremental compilation at the same time. In theory this should allow for getting compile-time improvements for small changes while keeping the runtime performance of the generated code roughly the same as when compiling non-incrementally. The difference to #52309 is that this version also caches the pre-LTO version of LLVM bitcode. This allows for another layer of caching: 1. if the module itself has changed, we have to re-codegen and re-optimize. 2. if the module itself has not changed, but a module it imported from during ThinLTO has, we don't need to re-codegen and don't need to re-run the first optimization phase. Only the second (i.e. ThinLTO-) optimization phase is re-run. 3. if neither the module itself nor any of its imports have changed then we can re-use the final, post-ThinLTO version of the module. (We might have to load its pre-ThinLTO version though so it's available for other modules to import from) |
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| .. | ||
| .editorconfig | ||
| ArchiveWrapper.cpp | ||
| Linker.cpp | ||
| llvm-rebuild-trigger | ||
| PassWrapper.cpp | ||
| README | ||
| rustllvm.h | ||
| RustWrapper.cpp | ||
This directory currently contains some LLVM support code. This will generally be sent upstream to LLVM in time; for now it lives here. NOTE: the LLVM C++ ABI is subject to between-version breakage and must *never* be exposed to Rust. To allow for easy auditing of that, all Rust-exposed types must be typedef-ed as "LLVMXyz", or "LLVMRustXyz" if they were defined here. Functions that return a failure status and leave the error in the LLVM last error should return an LLVMRustResult rather than an int or anything to avoid confusion. When translating enums, add a single `Other` variant as the first one to allow for new variants to be added. It should abort when used as an input. All other types must not be typedef-ed as such.