[Bug target/81763] Issues with BMI on 32bit x86 apps on GCC 7.1+

[manuel.lauss at googlemail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81763

--- Comment #46 from Manuel Lauss <manuel.lauss at googlemail dot com> ---
Created attachment 43257
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=43257&action=edit
reducest testcase

reduced testcase for Jakub's patch in comment #36 and the build failure it
causes in comment #42:

g++ (Gentoo 7.2.0-r1 p1.1) 7.2.0

g++ -m32 -O2 -mbmi -fPIC -fno-strict-aliasing -c testcase.i
testcase.i:126:12: warning: ‘unsigned int {anonymous}::bc::bn()’ used but never
defined
   unsigned bn();
            ^~
testcase.i:98:8: warning: ‘void {anonymous}::bc::bo({anonymous}::bc&)’ used but
never defined
   void bo(bc &);
        ^~
testcase.i:154:3: warning: ‘{anonymous}::bw::bw(unsigned int)’ used but never
defined
   bw(unsigned);
   ^~
testcase.i: In function ‘bool bz({anonymous}::bw&, ai::as, by&, bool,
ai::av&)’:
testcase.i:178:1: internal compiler error: in gen_split_178, at
config/i386/i386.md:8623
 }
 ^