The Linux helpers linked LLVM 22.1.8's release archive. The helper's code
generation is LLVM's code, so building that LLVM from its release sources
with ThinLTO and with a profile of the helper's own work makes code
generation 5-9% faster than the helper as released, with identical objects.
- native/llvm-codegen/llvm.profdata.gz is the profile, collected by
scripts/refresh-llvm-profile.mjs: it builds LLVM with IR instrumentation
and an instrumented helper, and runs that helper on tsc-ts, five Effect
fixtures, the runtime benchmark workloads and every 50th corpus program
(scripts/llvm-helper-inputs.mjs). It follows LLVM's sources, so it needs
a refresh when LLVM is bumped.
- scripts/build-llvm-dist.mjs builds LLVM with that profile and ThinLTO,
and packs it with a checksum. The llvm-dist workflow, run by hand, builds
it for x64 and arm64, requires a helper linked against it to give the
same objects as one linked against the release archive
(scripts/check-llvm-dist.mjs), prints both helpers' times and the
profile's mismatch count, and attaches the archive to the LLVM_DIST_TAG
release of this repository.
- The release workflow's Linux jobs, and the wasm32-wasi job, which also
uploads the x64 GNU helper, download that archive and build the helper
with SCRIPTC_LLVM_THINLTO=1: clang, lld and ThinLTO, and the profile for
the helper's own sources. Without the archive, or if that build fails,
the helper links the release archive as before.
- The four Linux helper packages share their build in
native/llvm-codegen/linux-helper.mjs. Without SCRIPTC_LLVM_THINLTO it
builds the same executable as before.
