https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81693
--- Comment #21 from Dominique d'Humieres <dominiq at lps dot ens.fr> --- % /opt/gcc/gcc8w/bin/gcc /opt/gcc/work/gcc/testsuite/gcc.dg/torture/pr25967-1.c -m32 -g % lldb a.out (lldb) target create "a.out" Current executable set to 'a.out' (i386). (lldb) run Process 25578 launched: '/Users/dominiq/Documents/Fortran/g95bench/win/f90/bug/a.out' (i386) Process 25578 stopped * thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=EXC_I386_GPFLT) frame #0: 0xa152b200 libdyld.dylib`misaligned_stack_error_ libdyld.dylib`misaligned_stack_error_: -> 0xa152b200 <+0>: movdqa %xmm0, 0x10(%esp) 0xa152b206 <+6>: movdqa %xmm1, 0x20(%esp) 0xa152b20c <+12>: movdqa %xmm2, 0x30(%esp) 0xa152b212 <+18>: movdqa %xmm3, 0x40(%esp) (lldb) b main Breakpoint 1: where = a.out`main + 5 at pr25967-1.c:62, address = 0x00001f44 (lldb) run There is a running process, kill it and restart?: [Y/n] y Process 25578 exited with status = 9 (0x00000009) Process 25583 launched: '/Users/dominiq/Documents/Fortran/g95bench/win/f90/bug/a.out' (i386) Process 25583 stopped * thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 1.1 frame #0: 0x00001f44 a.out`main at pr25967-1.c:62 59 main () 60 { 61 /* Align exception handler stack to 16 bytes. */ -> 62 asm ("and $-16, %" STACK_POINTER "; \ 63 push $" STRING (SS) "; \ 64 push $" STRING (SP) "; \ 65 push $" STRING (FLAGS) "; \ (lldb) disass -a 0x00001f44 a.out`main: 0x1f3f <+0>: calll 0x1f70 ; __x86.get_pc_thunk.ax -> 0x1f44 <+5>: andl $-0x10, %esp 0x1f47 <+8>: pushl $0x12345675 ; imm = 0x12345675 0x1f4c <+13>: pushl $0x12345674 ; imm = 0x12345674 0x1f51 <+18>: pushl $0x12345673 ; imm = 0x12345673 0x1f56 <+23>: pushl $0x12345672 ; imm = 0x12345672 0x1f5b <+28>: pushl $0x12345671 ; imm = 0x12345671 0x1f60 <+33>: pushl $0x12345670 ; imm = 0x12345670 0x1f65 <+38>: jmp 0x1ed0 ; fn at pr25967-1.c:38 0x1f6a <+43>: movl $0x0, %eax 0x1f6f <+48>: retl % /opt/gcc/gcc8w/bin/gcc /opt/gcc/work/gcc/testsuite/gcc.dg/torture/pr25967-1.c -g % lldb ./a.out (lldb) target create "./a.out" Current executable set to './a.out' (x86_64). (lldb) run Process 25632 launched: './a.out' (x86_64) Process 25632 exited with status = 0 (0x00000000) (lldb) b main Breakpoint 1: where = a.out`main at pr25967-1.c:62, address = 0x0000000100000f4b (lldb) run Process 25636 launched: './a.out' (x86_64) Process 25636 stopped * thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 1.1 frame #0: 0x0000000100000f4b a.out`main at pr25967-1.c:62 59 main () 60 { 61 /* Align exception handler stack to 16 bytes. */ -> 62 asm ("and $-16, %" STACK_POINTER "; \ 63 push $" STRING (SS) "; \ 64 push $" STRING (SP) "; \ 65 push $" STRING (FLAGS) "; \ (lldb) disass -a 0x0000000100000f4b a.out`main: -> 0x100000f4b <+0>: andq $-0x10, %rsp 0x100000f4f <+4>: pushq $0x12345675 ; imm = 0x12345675 0x100000f54 <+9>: pushq $0x12345674 ; imm = 0x12345674 0x100000f59 <+14>: pushq $0x12345673 ; imm = 0x12345673 0x100000f5e <+19>: pushq $0x12345672 ; imm = 0x12345672 0x100000f63 <+24>: pushq $0x12345671 ; imm = 0x12345671 0x100000f68 <+29>: pushq $0x12345670 ; imm = 0x12345670 0x100000f6d <+34>: jmp 0x100000ed2 ; fn at pr25967-1.c:40 0x100000f72 <+39>: movl $0x0, %eax 0x100000f77 <+44>: retq