/* va_list.c - tinycc support for va_list on X86_64 */ #if defined __x86_64__ /* Avoid include files, they may not be available when cross compiling */extern void abort(void); /* This should be in sync with our include/stdarg.h */enum __va_arg_type {    __va_gen_reg, __va_float_reg, __va_stack}; /* GCC compatible definition of va_list. *//*predefined by TCC (tcc_predefs.h):typedef struct {    unsigned int gp_offset;    unsigned int fp_offset;    union {        unsigned int overflow_offset;        char *overflow_arg_area;    };    char *reg_save_area;} __builtin_va_list[1];*/ extern void *memcpy(void *dest, const void *src, unsigned long n); void *__va_arg(__builtin_va_list ap,               int arg_type,               int size, int align){    size = (size + 7) & ~7;    align = (align + 7) & ~7;    switch ((enum __va_arg_type)arg_type) {    case __va_gen_reg:        if (ap->gp_offset + size <= 48) {            ap->gp_offset += size;            return ap->reg_save_area + ap->gp_offset - size;        }        goto use_overflow_area;     case __va_float_reg:        if (ap->fp_offset < 128 + 48) {            ap->fp_offset += 16;            if (size == 8)                return ap->reg_save_area + ap->fp_offset - 16;            if (ap->fp_offset < 128 + 48) {                memcpy(ap->reg_save_area + ap->fp_offset - 8,                       ap->reg_save_area + ap->fp_offset, 8);                ap->fp_offset += 16;                return ap->reg_save_area + ap->fp_offset - 32;            }        }        goto use_overflow_area;     case __va_stack:    use_overflow_area:        ap->overflow_arg_area += size;        ap->overflow_arg_area = (char*)((long long)(ap->overflow_arg_area + align - 1) & -align);        return ap->overflow_arg_area - size;     default: /* should never happen */        abort();        return 0;    }}#endif