github.com/afumu/libc@v0.0.6/musl/src/math/x86_64/llrint.c (about)

     1  #include <math.h>
     2  
     3  long long llrint(double x)
     4  {
     5  	long long r;
     6  	__asm__ ("cvtsd2si %1, %0" : "=r"(r) : "x"(x));
     7  	return r;
     8  }