case 17: return UNW_X86_ST1;
case 18: return UNW_X86_ST2;
case 19: return UNW_X86_ST3;
case 17: return UNW_X86_ST1;
case 18: return UNW_X86_ST2;
case 19: return UNW_X86_ST3;
case 21: return UNW_X86_ST5;
case 22: return UNW_X86_ST6;
case 23: return UNW_X86_ST7;
case 21: return UNW_X86_ST5;
case 22: return UNW_X86_ST6;
case 23: return UNW_X86_ST7;