This change is a step towards fixing one long-standing problem with LLVM's debug WASM codegen: excessive use of locals. One local for each temporary value in IR (roughly speaking). This has a lot of problems: 1) It makes it easy to hit engine limitations of 50K locals with certain code patterns and large functions. 2) It makes for larger binaries that are slower to load and slower to compile to native code. 3) It makes certain compilation strategies (spill all WASM locals to stack, for example) for debug code excessively expensive and makes debug WASM code either run very slow, or be less debuggable. 4) It slows down LLVM itself. This change addresses these partially by running a limited version of the stackification pass for unoptimized code, one that gets rid of the most 'obviously' unnecessary locals. Care needs to be taken to not impact LLVM's ability to produce high quality debug variable locations with this pass. To that end: 1) We only allow stackification when it doesn't require moving any instructions. 2) We disable stackification of any locals that are used in DEBUG_VALUEs, or as a frame base. I have verified on a moderately large example that the baseline and the diff produce the same kinds (local/global/stack) of locations, and the only differences are due to the shifting of instruction offsets, with many local.[get|set]s not being present anymore. Even with this quite conservative approach, the results are pretty good: 1) 30% reduction in raw code size, up to 10x reduction in the number of locals for select large methods (~1000 => ~100). 2) ~10% reduction in instructions retired for an "llc -O0" run on a moderately sized input.
Register assembly printer passes in the pass registry. This makes it possible to use `llc -start-before=<target>-asm-printer ...` in tests. Adds a `char &ID` parameter to the AssemblyPrinter constructor to allow targets to use the `INITIALIZE_PASS` macros and register the pass in the pass registry. This currently has a default parameter so it won't break any targets that have not been updated.
- Fix build with `EXPENSIVE_CHECKS` - Remove unused `PassName::ID` to resolve warning - Mark `~SelectionDAGISel` virtual so AArch64 backend can work properly
This reverts commit de37c06f01772e02465ccc9f538894c76d89a7a1 to de37c06f01772e02465ccc9f538894c76d89a7a1 It still breaks EXPENSIVE_CHECKS build. Sorry.
Port selection dag isel to new pass manager. Only `AMDGPU` and `X86` support new pass version. `-verify-machineinstrs` in new pass manager belongs to verify instrumentation, it is enabled by default.
`llvm.trap` will be convert as unreachable which is terminator. Instruction after terminator will cause validation failed. This PR introduces a pass to clean instruction after terminator. Fixes: https://github.com/llvm/llvm-project/issues/68770 Reapply: #90207
Reverts llvm/llvm-project#90207 LLD Bots are broken.
`llvm.trap` will be convert as `unreachable` which is terminator. Instruction after terminator will cause validation failed. This PR introduces a pass to clean instruction after terminator. Fixes: #68770.
This adds `WebAssemblyRefTypeMem2Local` pass, which changes the address spaces of reference type `alloca`s to `addrspace(1)`. This in turn changes the address spaces of all `load` and `store` instructions that use the `alloca`s. `addrspace(1)` is `WASM_ADDRESS_SPACE_VAR`, and loads and stores to this address space become `local.get`s and `local.set`s, thanks to the Wasm local IR support added in https://github.com/llvm/llvm-project/commit/82f92e35c6464e23859c29422956caaceb623967. In a follow-up PR, I am planning to replace the usage of mem2reg pass with this to solve the reference type `alloca` problems described in #81575.
This will make it easy for callers to see issues with and fix up calls to createTargetMachine after a future change to the params of TargetMachine. This matches other nearby enums. For downstream users, this should be a fairly straightforward replacement, e.g. s/CodeGenOpt::Aggressive/CodeGenOptLevel::Aggressive or s/CGFT_/CodeGenFileType::