tessl-llvm

Migrate an out-of-tree LLVM project to a new LLVM version (e.g., LLVM 21 → 22). Covers CMake bump, common LLVM 22 API breakages, header moves, pass renames, and opaque pointer migration.

Add a New Pass Manager (NPM) pass to an LLVM 22 in-tree or out-of-tree project. Covers FunctionPass, ModulePass, LoopPass, and CGSCCPass kinds, registration, pipeline wiring, CMake, and lit testing.

Scaffold an out-of-tree LLVM 22 compiler/language project from scratch. Covers CMake configuration, finding LLVM, linking components, a minimal LLVMContext driver, and build instructions.

Add a new target backend skeleton to LLVM 22. Covers CMake registration, TargetInfo, TargetMachine, MCTargetDesc, minimal TableGen register/instruction defs, and wiring into the LLVM build.

Lower source-language struct, union, and tuple types to LLVM 22 IR. Covers creating StructType, computing field offsets, emitting GEP for field access, packed vs. padded layouts, unions via largest-member types, passing structs by value vs. pointer, and the alloca+mem2reg pattern for struct locals.

Write lit tests with FileCheck for LLVM 22 IR transforms, pass output, and codegen. Covers RUN lines, CHECK patterns, common directives, negative checks, and running tests with llvm-lit.

Set up an ORC JIT v2 execution engine for a language runtime using LLVM 22. Covers LLJIT, LLLazyJIT, ThreadSafeModule, symbol exposure, optimization pipeline, and calling JIT'd functions.

Lower a toy language AST to LLVM 22 IR using IRBuilder. Covers project setup, AST node types, expression lowering, control flow, functions, structs, and applying mem2reg.

Guide LLVM 22's auto-vectorizer and SLP vectorizer from a frontend. Covers loop vectorization metadata, interleaving, loop distribution, marking parallel accesses, controlling SLP, and how to check whether vectorization happened.

Instrument LLVM 22 IR for AddressSanitizer (ASan), UndefinedBehaviorSanitizer (UBSan), or ThreadSanitizer (TSan). Covers enabling sanitizers via TargetMachine/PassBuilder, adding manual shadow-memory checks, inserting UBSan runtime calls, and CMake setup.

Enable Link-Time Optimization (LTO and ThinLTO) for an LLVM 22-based compiler. Covers full LTO vs ThinLTO trade-offs, bitcode emission from a frontend, LLD integration, out-of-tree whole-program optimization via ModulePassManager, and common debugging tips.

Add a new LLVM IR intrinsic in LLVM 22. Covers TableGen definition, header regeneration, IRBuilder call-site usage, verifier rules, and lit testing.

Add garbage-collection support to an LLVM 22 IR frontend. Covers the shadow-stack (gcroot) model for simple GCs and the statepoint/gc.relocate model for moving/relocating collectors, including the RewriteStatepointsForGC pass and StackMap section.

Add exception handling (try/catch/finally) to an LLVM 22 IR frontend using invoke, landingpad, and the Itanium C++ ABI. Covers personality function, invoke vs call, catch dispatch, __cxa_begin/end_catch, resume, cleanup blocks, and Windows SEH notes.

Add DWARF debug info to an existing LLVM 22 IR frontend. Covers DIBuilder setup, compile unit, function subprograms, local variable declarations, source locations on instructions, and module flags.

Add or wire a calling convention in an LLVM 22 in-tree target or document IR-level ABI choices for out-of-tree frontends. Covers CallingConv IDs, TableGen CallingConv.td, CCState/CCValAssign hooks, ISel lowering, and tests.

Add function/parameter attributes and IR metadata to LLVM 22 IR to unlock optimizer opportunities. Covers NoUnwind, ReadNone, NoCapture, Noundef, loop vectorization hints, branch weights, TBAA, !range, and !nonnull.

Use and extend alias analysis in LLVM 22. Covers querying AAResults from a function pass, using IR-level hints (noalias, TBAA) as the preferred approach, writing a custom AA analysis with the New Pass Manager, and common ModRef patterns.