https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120082
--- Comment #3 from John David Anglin <danglin at gcc dot gnu.org> --- Fails at first cmpb: => 0x40000000000067bc <main+452>: cmpb,*<> r0,ret0,0x4000000000006804 <main+524> 0x40000000000067c0 <main+456>: depdi,z,* -7,31,5,ret0 0x40000000000067c4 <main+460>: cmpb,*<> ret0,ret1,0x4000000000006804 <main+524> (gdb) p/x $ret0 $1 = 0x19 (gdb) stepi 0x40000000000067c0 34 if (x[i] != (i ? 0 : 0x1900000000)) (gdb) 35 __builtin_abort(); (gdb) p/x $ret0 $2 = 0x1900000000 (gdb) p/x $ret1 $3 = 0x0 Looks like endian issue.