This patch adds a lightweight instance of Attributor that only deduces
This is just an initial version and I might be missing some attributes,
but the goal is to have a version that only focuses on attributes to
replace the function-attrs pass. Please let me know if I am missing
any important knobs for the Attributor.
The initial version has a few open issues, the main one probably being
compile time. The main additional functionality I'd like to see in genera
l is propagating attributes to call sites.
- compile time The current version increase O3 +2.67% and ThinLTO +6.18% when replacing FunctionAttr https://llvm-compile-time-tracker.com/compare.php?from=c4bb3e073548cf436d5fa0406e3ae75e94684dec&to=d992630a69c79a2587d736e6a88f448850413bd1&stat=instructions%3Au Both are with an additional change to preserve more analysis, like FunctionAttrs CGSCC run.
- some missed attribute inference