fabs.c File Reference

#include <math.h>

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Functions
_Check_return_ double __cdecl	fabs (_In_ double x)

Function Documentation

fabs()

_Check_return_ double __cdecl fabs

(

_In_ double

x

)

Definition at line 17 of file fabs.c.

{
    /* Load the value as uint64 */
    unsigned long long u64 = *(unsigned long long*)&x;
 
    /* Clear the sign bit */
    u64 &= ~(1ULL << 63);
 
    /* Check for NAN */
    if (u64 > 0x7FF0000000000000ull)
    {
#ifdef _M_IX86
        /* Set error bit */
        *(unsigned long long*)&x |= 0x0008000000000000ull;
#endif
        return x;
    }
 
    /* Convert back to double */
    return *(double*)&u64;
}