Revision 6046c620 include/qemu/int128.h
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#ifndef INT128_H |
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#define INT128_H |
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#include <assert.h> |
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#include <stdint.h> |
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#include <stdbool.h> |
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typedef struct Int128 Int128; |
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struct Int128 {
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static inline Int128 int128_add(Int128 a, Int128 b) |
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{
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Int128 r = { a.lo + b.lo, a.hi + b.hi };
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r.hi += (r.lo < a.lo) || (r.lo < b.lo); |
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return r; |
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uint64_t lo = a.lo + b.lo; |
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/* a.lo <= a.lo + b.lo < a.lo + k (k is the base, 2^64). Hence, |
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* a.lo + b.lo >= k implies 0 <= lo = a.lo + b.lo - k < a.lo. |
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* Similarly, a.lo + b.lo < k implies a.lo <= lo = a.lo + b.lo < k. |
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* |
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* So the carry is lo < a.lo. |
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*/ |
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return (Int128) { lo, (uint64_t)a.hi + b.hi + (lo < a.lo) };
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} |
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static inline Int128 int128_neg(Int128 a) |
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{
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a.lo = ~a.lo; |
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a.hi = ~a.hi; |
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return int128_add(a, int128_one()); |
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uint64_t lo = -a.lo; |
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return (Int128) { lo, ~(uint64_t)a.hi + !lo };
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} |
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static inline Int128 int128_sub(Int128 a, Int128 b) |
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{
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return int128_add(a, int128_neg(b));
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return (Int128){ a.lo - b.lo, a.hi - b.hi - (a.lo < b.lo) };
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} |
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static inline bool int128_nonneg(Int128 a) |
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static inline bool int128_ge(Int128 a, Int128 b) |
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{
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return int128_nonneg(int128_sub(a, b));
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return a.hi > b.hi || (a.hi == b.hi && a.lo >= b.lo);
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} |
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static inline bool int128_lt(Int128 a, Int128 b) |
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