[Bug ipa/113291] New: [14 Regression] compilation never (?) finishes with recursive always_inline functions at -O and above

["zsojka at seznam dot cz" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113291

            Bug ID: 113291
           Summary: [14 Regression] compilation never (?) finishes with
                    recursive always_inline functions at -O and above
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: ipa
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zsojka at seznam dot cz
                CC: marxin at gcc dot gnu.org
  Target Milestone: ---
              Host: x86_64-pc-linux-gnu
            Target: x86_64-pc-linux-gnu

Created attachment 57015
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=57015&action=edit
reduced testcase

Compiler output:
$ time x86_64-pc-linux-gnu-gcc -O testcase.c -Wall -W
testcase.c:13:1: warning: 'always_inline' function might not be inlinable
[-Wattributes]
   13 | f1 (void)
      | ^~
testcase.c:6:1: warning: 'always_inline' function might not be inlinable
[-Wattributes]
    6 | f0 (void)
      | ^~
testcase.c: In function 'f0':
testcase.c:6:1: warning: infinite recursion detected [-Winfinite-recursion]
In function 'f1',
    inlined from 'f0' at testcase.c:8:3:
testcase.c:16:3: note: recursive call
   16 |   f0 ();
      |   ^~~~~
testcase.c: In function 'f1':
testcase.c:13:1: warning: infinite recursion detected [-Winfinite-recursion]
   13 | f1 (void)
      | ^~
testcase.c:15:3: note: recursive call
   15 |   f1 ();
      |   ^~~~~
^C

real    1m21.533s
user    0m0.002s
sys     0m0.000s


$ x86_64-pc-linux-gnu-gcc -v
Using built-in specs.
COLLECT_GCC=/repo/gcc-trunk/binary-latest-amd64/bin/x86_64-pc-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-r14-7023-20240109134751-gab6224dfe12-checking-yes-rtl-df-extra-nobootstrap-amd64/bin/../libexec/gcc/x86_64-pc-linux-gnu/14.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /repo/gcc-trunk//configure --enable-languages=c,c++
--enable-valgrind-annotations --disable-nls --enable-checking=yes,rtl,df,extra
--disable-bootstrap --with-cloog --with-ppl --with-isl
--build=x86_64-pc-linux-gnu --host=x86_64-pc-linux-gnu
--target=x86_64-pc-linux-gnu --with-ld=/usr/bin/x86_64-pc-linux-gnu-ld
--with-as=/usr/bin/x86_64-pc-linux-gnu-as --disable-libstdcxx-pch
--prefix=/repo/gcc-trunk//binary-trunk-r14-7023-20240109134751-gab6224dfe12-checking-yes-rtl-df-extra-nobootstrap-amd64
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 14.0.0 20240109 (experimental) (GCC)