http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53383
--- Comment #11 from H.J. Lu <hjl.tools at gmail dot com> 2012-05-20 02:04:40 UTC --- (In reply to comment #10) > The problem is va_args doing alignment based on stack pointer, i.e. in: > int > > return va_arg (p, __int128); > } > > addq $15, %rax > andq $-16, %rax This isn't necessary. If __int128 is put on stack by caller, the stack must be aligned at 16 bytes. > leaq 16(%rax), %rdx > movq %rdx, -72(%rsp) > movq (%rax), %rax > ret > .cfi_endproc > .LFE0: > > this will get out of sync with hard coded offsets if rsp hapepns to be > misaligned. I don't think it will happen.
