[FuncAttrs] Infer `norecurse` for funcs with calls to `nocallback` callees (#76372)
This patch adds missing `norecurse` attrs to funcs that only call intrinsics with `nocallback` attrs. Fixes the regression found in https://github.com/dtcxzyw/llvm-opt-benchmark/pull/45#discussion_r1436148743. The function loses `norecurse` attr because it calls `@llvm.fabs.f64`, which is not marked as `norecurse`. Since `norecurse` is not a default attribute of intrinsics and it is ambiguous for intrinsics, I decided to use the existing `callback` attributes. > nocallback This attribute indicates that the function is only allowed to jump back into caller’s module by a return or an exception, and is not allowed to jump back by invoking a callback function, a direct, possibly transitive, external function call, use of longjmp, or other means. It is a compiler hint that is used at module level to improve dataflow analysis, dropped during linking, and has no effect on functions defined in the current module. See also https://llvm.org/docs/LangRef.html#function-attributes.
Loading
Please sign in to comment