tinycc/lib/va_list.c
herman ten brugge 4a16bebfab Struct va_arg fix
lib/va_list.c:
- Handle struct {double, double} correctly

arm64-gen.c:
riscv64-gen.c:
x86_64-gen.c:
- Allow zero sized structs to work with va_arg

tcctest.c:
- Add new va_arg test code

test/bug.c:
- Remove tst2 va_arg test
2020-09-17 08:42:28 +02:00

68 lines
1.9 KiB
C

/* 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