ia32_sigframe
struct ia32_sigframe sf, *sfp;
sfp = (struct ia32_sigframe *)((uintptr_t)sp & ~0xF);
ASSYM(IA32_SIGF_HANDLER, offsetof(struct ia32_sigframe, sf_ah));
ASSYM(IA32_SIGF_UC, offsetof(struct ia32_sigframe, sf_uc));
CTASSERT(sizeof(struct ia32_sigframe) == 800);