[llvm-dev] always inliner only works when function is called from external function?

[David Blaikie via llvm-dev]

On Tue, Apr 11, 2017 at 12:27 AM Andrew Kelley via llvm-dev <
llvm-dev at lists.llvm.org> wrote:

> Observe:
>
> [nix-shell:~/tmp]$ cat test.ll
> define internal fastcc void @foo() {
> Entry:
>   call fastcc void @bar()
>   ret void
> }
>
> ; Function Attrs: alwaysinline
> define internal fastcc void @bar() #0 {
> Entry:
>   ret void
> }
>
> attributes #0 = { alwaysinline }
>
>
> [nix-shell:~/tmp]$ opt test.ll -always-inline -S
> ; ModuleID = 'test.ll'
> source_filename = "test.ll"
>
> define internal fastcc void @foo() {
> Entry:
>   call fastcc void @bar()
>   ret void
> }
>
> ; Function Attrs: alwaysinline
> define internal fastcc void @bar() #0 {
> Entry:
>   ret void
> }
>
> attributes #0 = { alwaysinline }
>
>
> If I delete "internal" from foo, then the optimziation pass in fact
> inlines bar. Is this intentional? Is there a way to make the always inliner
> pass work on internal functions like this too?
>

Is this a really representative test? the internal function has no callers
- so it doesn't really matter how it's optimized, right? Because it's dead
code.

My test case seems to show that if the function is used, then the inliner
will inline into it - but if it's dead code, it won't.


> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20170411/4645ebdc/attachment.html>