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Add address map and set

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This commit is contained in:
Andy Wingo 2022-04-12 21:41:26 +02:00
parent b0b4c4d893
commit d425620d37
5 changed files with 655 additions and 0 deletions
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45
address-hash.h Normal file
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#ifndef ADDRESS_HASH_H
#define ADDRESS_HASH_H
#include <stdint.h>
static uintptr_t hash_address(uintptr_t x) {
if (sizeof (x) < 8) {
// Chris Wellon's lowbias32, from https://nullprogram.com/blog/2018/07/31/.
x ^= x >> 16;
x *= 0x7feb352dU;
x ^= x >> 15;
x *= 0x846ca68bU;
x ^= x >> 16;
return x;
} else {
// Sebastiano Vigna's splitmix64 integer mixer, from
// https://prng.di.unimi.it/splitmix64.c.
x ^= x >> 30;
x *= 0xbf58476d1ce4e5b9U;
x ^= x >> 27;
x *= 0x94d049bb133111ebU;
x ^= x >> 31;
return x;
}
}
// Inverse of hash_address from https://nullprogram.com/blog/2018/07/31/.
static uintptr_t unhash_address(uintptr_t x) {
if (sizeof (x) < 8) {
x ^= x >> 16;
x *= 0x43021123U;
x ^= x >> 15 ^ x >> 30;
x *= 0x1d69e2a5U;
x ^= x >> 16;
return x;
} else {
x ^= x >> 31 ^ x >> 62;
x *= 0x319642b2d24d8ec3U;
x ^= x >> 27 ^ x >> 54;
x *= 0x96de1b173f119089U;
x ^= x >> 30 ^ x >> 60;
return x;
}
}
#endif // ADDRESS_HASH_H