(gdb) run Starting program: /home/dmsh/dev/factor-git/factor [Thread debugging using libthread_db enabled] [New Thread 0xaec7cb70 (LWP 21047)] Program received signal SIGILL, Illegal instruction. 0xaf2daeb8 in ?? () (gdb) disassemble $pc $pc+100 Dump of assembler code from 0xaf2daeb8 to 0xaf2daf1c: 0xaf2daeb8: movsd (%esp),%xmm0 0xaf2daebd: add $0x4,%esp 0xaf2daec0: sub $0x8,%esi 0xaf2daec3: mov 0x1c(%esp),%eax 0xaf2daec7: mov %eax,(%esp) 0xaf2daeca: movsd %xmm0,0x4(%esp) 0xaf2daed0: call 0xb7f5ee20 0xaf2daed5: add $0x2c,%esp 0xaf2daed8: ret 0xaf2daed9: sbb $0xff,%al 0xaf2daedb: loopne 0xaf2daedd 0xaf2daedd: add %al,(%eax) 0xaf2daedf: add %dh,-0x64000000(%edx) 0xaf2daee5: push $0x2cc2b1d0 0xaf2daeea: jne 0xaf2dae9e 0xaf2daeec: imul $0x1068b275,(%ebx),%edi 0xaf2daef2: add %al,(%eax) 0xaf2daef4: add %ch,-0x10(%eax) 0xaf2daef7: scas %es:(%edi),%al 0xaf2daef8: sub $0x4ec83af,%eax 0xaf2daefd: add $0x4,%edi 0xaf2daf00: add $0x8,%esi 0xaf2daf03: mov -0x8(%esi),%eax 0xaf2daf06: mov 0x809e218,%ecx 0xaf2daf0c: mov 0x20(%ecx),%ecx 0xaf2daf0f: mov %eax,(%edi) 0xaf2daf11: mov %ecx,(%esi) 0xaf2daf13: movl $0xb1cfd57c,-0x4(%esi) 0xaf2daf1a: call 0xaf187cf0 End of assembler dump. (gdb)