modernc.org/cc@v1.0.1/testdata/gcc-6.3.0/gcc/testsuite/gcc.c-torture/compile/920413-1.c (about)

     1  union u {double d;long long ll;};
     2  f(double x, int n){union u v;v.d=x;if(n>=0){v.ll<<=63;}else{v.ll+=1<<-n;v.ll>>=-n;}return v.ll;}