[Bug ipa/80277] New: ipa-icf missing overlooking functions

[linux at carewolf dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80277

            Bug ID: 80277
           Summary: ipa-icf missing overlooking functions
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: ipa
          Assignee: unassigned at gcc dot gnu.org
          Reporter: linux at carewolf dot com
  Target Milestone: ---

Created attachment 41100
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=41100&action=edit
icf.cc

Several functions that produce identical assembler are not merged by ipa-icf. I
have attached an example, and only the two functions foo0 and foo1 that are
identical in every detail are meged, though all the foo* functions produce
identical assembler.

I theorice it is because the function signature is compared before the content,
and the templates and different types might cause that early comparison to fail
when it shouldn't.

I added a second test that just changed the return value but kept everything
else identical and it also wasn't merged.


A little unrelated: I noted the ipa-icf optimization is undone by -O3 as it
re-inlines, though that is kind of pointless unless it is needed for second
level inlining.