add riscv64 architecture support

[musl] / src / math / riscv64 / fabs.c

#include <math.h>

#if __riscv_flen >= 64

double fabs(double x)
{
        __asm__ ("fabs.d %0, %1" : "=f"(x) : "f"(x));
        return x;
}

#else

#include "../fabs.c"

#endif