llvm-project

5ce34958 - [Coro] Prebuild a module-level debug info set and share it between all coroutine clones (#118628)

[Coro] Prebuild a module-level debug info set and share it between all coroutine clones (#118628) Summary: CoroCloner, by calling into CloneFunctionInto, does a lot of repeated work priming DIFinder and building a list of common module-level debug info metadata. For programs compiled with full debug info this can get very expensive. This diff builds the data once and shares it between all clones. Anecdata for a sample cpp source file compiled with full debug info: | | Baseline | IdentityMD set | Prebuilt CommonDI (cur.) | |-----------------|----------|----------------|--------------------------| | CoroSplitPass | 306ms | 221ms | 68ms | | CoroCloner | 101ms | 72ms | 0.5ms | | CollectCommonDI | - | - | 63ms | | Speed up | 1x | 1.4x | 4.5x | Note that CollectCommonDebugInfo happens once *per coroutine* rather than per clone. Test Plan: ninja check-llvm-unit ninja check-llvm Compiled a sample internal source file, checked time trace output for scope timings.