Nils O. Selåsdal
91 lines
1.3 KiB
C
91 lines
1.3 KiB
C
#ifndef UC_MATH_H_
|
|
#define UC_MATH_H_
|
|
|
|
#include <stdint.h>
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
uint32_t
|
|
uc_gcd_32(uint32_t a, uint32_t b);
|
|
|
|
uint64_t
|
|
uc_gcd_64(uint64_t a, uint64_t b);
|
|
|
|
uint32_t
|
|
uc_phi_32(uint32_t N);
|
|
|
|
uint64_t
|
|
uc_phi_64(uint64_t N);
|
|
|
|
#if defined(__has_builtin)
|
|
# if __has_builtin(__builtin_clzll)
|
|
# define HAVE_BUILTIN_CLZ 1
|
|
# endif
|
|
#endif
|
|
|
|
|
|
// Note: the nextpow2 functions have undefined behavior if
|
|
// x > 2^(n-1) for n of the 32 or 64 bit variants
|
|
|
|
#if HAVE_BUILTIN_CLZ
|
|
|
|
static inline uint32_t
|
|
uc_nextpow2(uint32_t x)
|
|
{
|
|
if (x <= 1) return 1;
|
|
return 1u << (32 - __builtin_clz(x - 1));
|
|
return x;
|
|
}
|
|
|
|
static inline uint64_t
|
|
uc_nextpow2_64(uint64_t x)
|
|
{
|
|
if (x <= 1) return 1;
|
|
return (uint64_t)1 << (64 - __builtin_clzll(x - 1));
|
|
return x;
|
|
}
|
|
#else
|
|
static inline uint32_t
|
|
uc_nextpow2(uint32_t x)
|
|
{
|
|
if (x == 0) {
|
|
return 1;
|
|
}
|
|
x--;
|
|
x |= x >> 1;
|
|
x |= x >> 2;
|
|
x |= x >> 4;
|
|
x |= x >> 8;
|
|
x |= x >> 16;
|
|
x++;
|
|
|
|
return x;
|
|
}
|
|
|
|
static inline uint64_t
|
|
uc_nextpow2_64(uint64_t x)
|
|
{
|
|
if (x == 0) {
|
|
return 1;
|
|
}
|
|
x--;
|
|
x |= x >> 1;
|
|
x |= x >> 2;
|
|
x |= x >> 4;
|
|
x |= x >> 8;
|
|
x |= x >> 16;
|
|
x |= x >> 32;
|
|
x++;
|
|
|
|
return x;
|
|
}
|
|
#endif
|
|
|
|
#undef HAVE_BUILTIN_CLZ
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
#endif
|