[Bug lto/78034] New: undefined reference during LTO linking.

[pawel_sikora at zoho dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78034

            Bug ID: 78034
           Summary: undefined reference during LTO linking.
           Product: gcc
           Version: 6.2.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: lto
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pawel_sikora at zoho dot com
  Target Milestone: ---

Created attachment 39834
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=39834&action=edit
testcase

% make
rm -f *.o *.a
g++ -m32 -Og -flto -fuse-ld=gold -g0 -march=pentium4 integer.cpp -c
gcc-ar -rv libinteger.a integer.o
/usr/bin/ar: creating libinteger.a
a - integer.o
g++ -m32 -Og -flto -fuse-ld=gold -g0 -march=pentium4 test.cpp -o test -L.
-linteger
/tmp/ccAeSuk8.ltrans0.ltrans.o:<artificial>:function SSE2_Multiply4(unsigned
int*, unsigned int const*, unsigned int const*): error: undefined reference to
'LMul2'
collect2: error: ld returned 1 exit status



the 'LMul2' is an assembly label generated by macro-hell.
without -flto it links fine.