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Llvm19 - #71
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RedrockerLi wants to merge 3 commits into
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Llvm19#71RedrockerLi wants to merge 3 commits into
RedrockerLi wants to merge 3 commits into
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LLVM 19's headers need std::is_class_v / std::is_pointer_v / std::optional / std::size. Under C++14 the build produced 3418 errors, every one of them from inside /usr/lib/llvm-19/include/ rather than from this project. Raising the standard takes that to zero; llvm-config-19 --cxxflags also emits -std=c++17.
The legacy pass manager API still COMPILES against LLVM 19: Debian's package still ships llvm/Pass.h, so FunctionPass, RegisterPass<>, getAnalysisUsage and getAnalysis<LoopInfoWrapperPass>() all build unchanged. What is gone is the INVOCATION -- `opt-19 -load x.so -mapperPass kernel.bc` fails with "The `opt -passname` syntax for the new pass manager is not supported, please use `opt -passes=<pipeline>`". So the pass must be registered and invoked through a pipeline even though the old headers would still let it build. Converted mechanically: FunctionPass -> PassInfoMixin<mapperPass> runOnFunction(Function&) -> run(Function&, FunctionAnalysisManager&) RegisterPass<mapperPass> X -> llvmGetPassPluginInfo + parsing callback getAnalysis<LoopInfoWrap...> -> FAM.getResult<LoopAnalysis>(F) Two things worth knowing before rebasing this: * The LoopInfo was fetched from a HELPER (getTargetLoops), not from the pass entry point, so the analysis result is threaded in as a new parameter rather than looked up in place. * Only run()'s returns change, and they become PreservedAnalyses::all() -- the pass only READS the IR (it builds its own DFG/CGRA model and writes JSON), which is what the legacy `return false` plus setPreservesAll() meant. canMap(), a helper that genuinely returns bool, keeps its `return true;` / `return false;`. run() and canMap() end adjacently in the file, so conflating them is easy; it compiles right up until the return type is checked. Also disambiguates `json`: including llvm/Passes/PassBuilder.h transitively pulls in llvm/Support/JSON.h, which declares llvm::json, so under the file's `using namespace llvm` a bare `json` collides with `using json = nlohmann::json`. The alias is dropped and the four uses are spelled nlohmann::json. Verified: builds clean against LLVM 19.1.7; the .so registers and runs (traced with -debug-pass-manager); on the FIR kernel it emits dfg.json and config.json, and the simulator's CGRACtrl parses the latter. See PORT.md.
Records why this branch exists, the exact three changes, the two silent upstream footguns (-O0 marks functions optnone so the new pass manager skips the pass entirely; -O3 alone fuses the MAC into llvm.fmuladd.f32 which no FU implements and mapping fails), the verified invocation, and what the ported build reproduces against the vendored golden config. Also records what the port did NOT need: Mapper.cpp, DFG.cpp, DFGNode.cpp, CGRA.cpp, CGRANode.cpp, CGRALink.cpp and all headers compile unmodified, because the codebase keeps LLVM at arm's length and uses no typed-pointer API anywhere -- so LLVM 15's opaque-pointer migration, normally the expensive part of a port like this, is a non-issue here.
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