On Tue, Oct 11, 2022 at 3:33 PM Alexandre Oliva <ol...@adacore.com> wrote: > > On Oct 11, 2022, Richard Biener <richard.guent...@gmail.com> wrote: > > > On Tue, Oct 11, 2022 at 1:57 PM Alexandre Oliva <ol...@adacore.com> wrote: > >> > >> On Oct 10, 2022, Richard Biener <richard.guent...@gmail.com> wrote: > >> > >> > As noted in the Cauldron Discussion I think you should do all > >> > instrumentation post-IPA only to simplify your life not needing to > >> > handle inlining of instrumentation > >> > >> I looked a bit into that after the Cauldron, and recalled why I wanted > >> to instrument before inlining: in the case of internal strub, that > >> introduces a wrapper, it's desirable to be able to inline the wrapper. > > > I think if the wrapper is created at IPA time it is also available for > > IPA inlining. > > Yeah, but now I'm not sure what you're suggesting. The wrapper is > instrumentation, and requires instrumentation of the wrapped > counterpart, so that can't be post-IPA.
IPA folks can probably explain better but there's IPA (local) analysis, IPA (global) propagation and IPA (local) code generation. You'd instrument (and actually create the wrappers) at IPA code generation time but virtually the wrapper would become existent somewhen during IPA propagation by means of a clone to be materialized (I understand the wrapper is something like a thunk). The IPA propagation phase would decide which calls should go to the wrapper (and instrumented function) and which can use the original uninstrumented function (maybe from local already strubbed functions). Richard. > > -- > Alexandre Oliva, happy hacker https://FSFLA.org/blogs/lxo/ > Free Software Activist GNU Toolchain Engineer > Disinformation flourishes because many people care deeply about injustice > but very few check the facts. Ask me about <https://stallmansupport.org>
