X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=qemu%2Finclude%2Fqemu%2Fint128.h;fp=qemu%2Finclude%2Fqemu%2Fint128.h;h=fb782aaddd4a84c3666ee67fe2f5d16ddd1bc12b;hb=e44e3482bdb4d0ebde2d8b41830ac2cdb07948fb;hp=0000000000000000000000000000000000000000;hpb=9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00;p=kvmfornfv.git diff --git a/qemu/include/qemu/int128.h b/qemu/include/qemu/int128.h new file mode 100644 index 000000000..fb782aadd --- /dev/null +++ b/qemu/include/qemu/int128.h @@ -0,0 +1,149 @@ +#ifndef INT128_H +#define INT128_H + +#include +#include +#include + +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_exts64(int64_t a) +{ + return (Int128) { .lo = a, .hi = (a < 0) ? -1 : 0 }; +} + +static inline Int128 int128_and(Int128 a, Int128 b) +{ + return (Int128) { a.lo & b.lo, a.hi & b.hi }; +} + +static inline Int128 int128_rshift(Int128 a, int n) +{ + int64_t h; + if (!n) { + return a; + } + h = a.hi >> (n & 63); + if (n >= 64) { + return (Int128) { h, h >> 63 }; + } else { + return (Int128) { (a.lo >> n) | ((uint64_t)a.hi << (64 - n)), h }; + } +} + +static inline Int128 int128_add(Int128 a, Int128 b) +{ + uint64_t lo = a.lo + b.lo; + + /* a.lo <= a.lo + b.lo < a.lo + k (k is the base, 2^64). Hence, + * a.lo + b.lo >= k implies 0 <= lo = a.lo + b.lo - k < a.lo. + * Similarly, a.lo + b.lo < k implies a.lo <= lo = a.lo + b.lo < k. + * + * So the carry is lo < a.lo. + */ + return (Int128) { lo, (uint64_t)a.hi + b.hi + (lo < a.lo) }; +} + +static inline Int128 int128_neg(Int128 a) +{ + uint64_t lo = -a.lo; + return (Int128) { lo, ~(uint64_t)a.hi + !lo }; +} + +static inline Int128 int128_sub(Int128 a, Int128 b) +{ + return (Int128){ a.lo - b.lo, (uint64_t)a.hi - b.hi - (a.lo < b.lo) }; +} + +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 a.hi > b.hi || (a.hi == b.hi && a.lo >= b.lo); +} + +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