1 int b=1; foo()2 int foo() 3 { 4 int a; 5 int c; 6 a=0xff; 7 for (;b;b--) 8 { 9 c=1; 10 asm(""::"r"(c)); 11 c=(signed char)a; 12 } 13 if (c!=-1) 14 abort(); 15 return c; 16 } main()17 int main() 18 { 19 foo(); 20 return 0; 21 } 22