mirror of
https://github.com/xemu-project/xemu.git
synced 2024-11-25 12:40:08 +00:00
b7cd3db6f4
The memory API supports 64-bit buses (e.g. PCI). A size on such a bus cannot be represented with a 64-bit data type, if both 0 and the entire address space size are to be represented. Futhermore, any address arithemetic may overflow and return unexpected results. Introduce a 128-bit signed integer type for use in such cases. Addition, subtraction, and comparison are the only operations supported. Signed-off-by: Avi Kivity <avi@redhat.com>
117 lines
1.9 KiB
C
117 lines
1.9 KiB
C
#ifndef INT128_H
|
|
#define INT128_H
|
|
|
|
typedef struct Int128 Int128;
|
|
|
|
struct Int128 {
|
|
uint64_t lo;
|
|
int64_t hi;
|
|
};
|
|
|
|
static inline Int128 int128_make64(uint64_t a)
|
|
{
|
|
return (Int128) { a, 0 };
|
|
}
|
|
|
|
static inline uint64_t int128_get64(Int128 a)
|
|
{
|
|
assert(!a.hi);
|
|
return a.lo;
|
|
}
|
|
|
|
static inline Int128 int128_zero(void)
|
|
{
|
|
return int128_make64(0);
|
|
}
|
|
|
|
static inline Int128 int128_one(void)
|
|
{
|
|
return int128_make64(1);
|
|
}
|
|
|
|
static inline Int128 int128_2_64(void)
|
|
{
|
|
return (Int128) { 0, 1 };
|
|
}
|
|
|
|
static inline Int128 int128_add(Int128 a, Int128 b)
|
|
{
|
|
Int128 r = { a.lo + b.lo, a.hi + b.hi };
|
|
r.hi += (r.lo < a.lo) || (r.lo < b.lo);
|
|
return r;
|
|
}
|
|
|
|
static inline Int128 int128_neg(Int128 a)
|
|
{
|
|
a.lo = ~a.lo;
|
|
a.hi = ~a.hi;
|
|
return int128_add(a, int128_one());
|
|
}
|
|
|
|
static inline Int128 int128_sub(Int128 a, Int128 b)
|
|
{
|
|
return int128_add(a, int128_neg(b));
|
|
}
|
|
|
|
static inline bool int128_nonneg(Int128 a)
|
|
{
|
|
return a.hi >= 0;
|
|
}
|
|
|
|
static inline bool int128_eq(Int128 a, Int128 b)
|
|
{
|
|
return a.lo == b.lo && a.hi == b.hi;
|
|
}
|
|
|
|
static inline bool int128_ne(Int128 a, Int128 b)
|
|
{
|
|
return !int128_eq(a, b);
|
|
}
|
|
|
|
static inline bool int128_ge(Int128 a, Int128 b)
|
|
{
|
|
return int128_nonneg(int128_sub(a, b));
|
|
}
|
|
|
|
static inline bool int128_lt(Int128 a, Int128 b)
|
|
{
|
|
return !int128_ge(a, b);
|
|
}
|
|
|
|
static inline bool int128_le(Int128 a, Int128 b)
|
|
{
|
|
return int128_ge(b, a);
|
|
}
|
|
|
|
static inline bool int128_gt(Int128 a, Int128 b)
|
|
{
|
|
return !int128_le(a, b);
|
|
}
|
|
|
|
static inline bool int128_nz(Int128 a)
|
|
{
|
|
return a.lo || a.hi;
|
|
}
|
|
|
|
static inline Int128 int128_min(Int128 a, Int128 b)
|
|
{
|
|
return int128_le(a, b) ? a : b;
|
|
}
|
|
|
|
static inline Int128 int128_max(Int128 a, Int128 b)
|
|
{
|
|
return int128_ge(a, b) ? a : b;
|
|
}
|
|
|
|
static inline void int128_addto(Int128 *a, Int128 b)
|
|
{
|
|
*a = int128_add(*a, b);
|
|
}
|
|
|
|
static inline void int128_subfrom(Int128 *a, Int128 b)
|
|
{
|
|
*a = int128_sub(*a, b);
|
|
}
|
|
|
|
#endif
|