[Bug c++/104597] New: LTO does not inline indirect call

["m.cencora at gmail dot com" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104597

            Bug ID: 104597
           Summary: LTO does not inline indirect call
           Product: gcc
           Version: 11.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: m.cencora at gmail dot com
  Target Milestone: ---

Given following files:
// main.cpp
using intfunc = int (*)();

intfunc getIntFunc(int i);

namespace
{
int test()
{
   auto func = getIntFunc(1);
   return func();
}
}

int main()
{
   return test();
}


// lib1.cpp
namespace
{

int getInt0()
{
   return 0;
}

int getInt1()
{
   return 1;
}

int getInt2()
{
   return 2;
}

}

using intfunc = int (*)();

intfunc getIntFunc(int i)
{
   if (i == 0)
   {
      return getInt0;
   }
   else if (i == 1)
   {
      return getInt1;
   }
   else if (i == 2)
   {
      return getInt2;
   }
   __builtin_abort();
}


and compilation with:
g++ -std=c++20 -Wall -Wextra -O3 -flto -fvisibility=hidden
-fvisibility-inlines-hidden -ffunction-sections -Wl,-gc-sections main.cpp
lib1.cpp -o test

Call to getInt1 does not get inlined:
Dump of assembler code for function main:
   0x0000000000001040 <+0>:     endbr64 
   0x0000000000001044 <+4>:     jmp    0x1140 <_ZN12_GLOBAL__N_17getInt1Ev>