math.h

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#pragma once
 
#include <stdint.h>
#include <stdlib.h>
 
#include <derive-c/core/prelude/macros.h>
 
static INLINE CONST size_t next_power_of_2(size_t x) {
    if (x == 0)
        return 1;
    x--;
    x |= x >> 1;
    x |= x >> 2;
    x |= x >> 4;
    x |= x >> 8;
    x |= x >> 16;
#if SIZE_MAX > 0xFFFFFFFF
    x |= x >> 32; // For 64-bit platforms
#endif
    return x + 1;
}
 
static bool INLINE CONST is_power_of_2(size_t x) { return x != 0 && (x & (x - 1)) == 0; }
 
static size_t INLINE CONST modulus_power_of_2_capacity(size_t index, size_t capacity) {
    ASSUME(is_power_of_2(capacity));
    // NOTE: If we know capacity is a power of 2, we can reduce the cost of 'index + 1 % capacity'
    return index & (capacity - 1);
}
 
static bool INLINE CONST is_aligned_pow2_exp(const void* ptr, unsigned exp) {
    uintptr_t const mask = (1U << exp) - 1;
    return (((uintptr_t)ptr) & mask) == 0;
}