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// uncrustify:off
#include <math.h>
// uncrustify:on
#include <stdint.h>
#include <string.h>
#include "nvim/math.h"
#ifdef INCLUDE_GENERATED_DECLARATIONS
# include "math.c.generated.h"
#endif
int xfpclassify(double d)
FUNC_ATTR_CONST
{
uint64_t m;
memcpy(&m, &d, sizeof(m));
int e = 0x7ff & (m >> 52);
m = 0xfffffffffffffULL & m;
switch (e) {
default:
return FP_NORMAL;
case 0x000:
return m ? FP_SUBNORMAL : FP_ZERO;
case 0x7ff:
return m ? FP_NAN : FP_INFINITE;
}
}
int xisinf(double d)
FUNC_ATTR_CONST
{
return FP_INFINITE == xfpclassify(d);
}
int xisnan(double d)
FUNC_ATTR_CONST
{
return FP_NAN == xfpclassify(d);
}
/// Count trailing zeroes at the end of bit field.
int xctz(uint64_t x)
{
// If x == 0, that means all bits are zeroes.
if (x == 0) {
return 8 * sizeof(x);
}
// Use compiler builtin if possible.
#if defined(__clang__) || (defined(__GNUC__) && (__GNUC__ >= 4))
return __builtin_ctzll(x);
#else
int count = 0;
// Set x's trailing zeroes to ones and zero the rest.
x = (x ^ (x - 1)) >> 1;
// Increment count until there are just zero bits remaining.
while (x) {
count++;
x >>= 1;
}
return count;
#endif
}
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