610   felem ftmp, ftmp2;  in felem_inv()  local
647   felem_mul(ftmp2, e64, e32); /* 2^64 - 2^0 */  in felem_inv()
649     felem_square(ftmp2, ftmp2);  in felem_inv()
651   felem_mul(ftmp2, ftmp2, e16); /* 2^80 - 2^0 */  in felem_inv()
653     felem_square(ftmp2, ftmp2);  in felem_inv()
655   felem_mul(ftmp2, ftmp2, e8); /* 2^88 - 2^0 */  in felem_inv()
657     felem_square(ftmp2, ftmp2);  in felem_inv()
659   felem_mul(ftmp2, ftmp2, e4); /* 2^92 - 2^0 */  in felem_inv()
660   felem_square(ftmp2, ftmp2); /* 2^93 - 2^1 */  in felem_inv()
661   felem_square(ftmp2, ftmp2); /* 2^94 - 2^2 */  in felem_inv()
662   felem_mul(ftmp2, ftmp2, e2); /* 2^94 - 2^0 */  in felem_inv()
663   felem_square(ftmp2, ftmp2); /* 2^95 - 2^1 */  in felem_inv()
664   felem_square(ftmp2, ftmp2); /* 2^96 - 2^2 */  in felem_inv()
665   felem_mul(ftmp2, ftmp2, in); /* 2^96 - 3 */  in felem_inv()
667   felem_mul(out, ftmp2, ftmp); /* 2^256 - 2^224 + 2^192 + 2^96 - 3 */  in felem_inv()