http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50351
--- Comment #3 from PcX <xunxun1982 at gmail dot com> 2011-09-12 12:55:55 UTC --- Using Eric Botcazou's test case, it also has the problem. gcc lex.c has no problem gcc -flto -fuse-linker-plugin lex.c it shows In file included from lex.c:15:0, from :0: lex.c: In function 'foo': lex.c:16:15: internal compiler error: in convert_move, at expr.c:330 Please submit a full bug report, with preprocessed source if appropriate. See <http://gcc.gnu.org/bugs.html> for instructions. lto-wrapper: gcc returned 1 exit status e:/mypack/mingw/bin/../lib/gcc/i686-w64-mingw32/4.7.0/../../../../i686-w64-mingw32/bin/ld.exe: lto-wrapper failed collect2.exe: error: ld returned 1 exit status gcc -flto -fuse-linker-plugin lex.c -msse2 has no problem.