| 414 | } |
| 415 | |
| 416 | static CanonicalForm |
| 417 | gcd_poly_0( const CanonicalForm & f, const CanonicalForm & g ) |
| 418 | { |
| 419 | CanonicalForm pi, pi1; |
| 420 | CanonicalForm C, Ci, Ci1, Hi, bi, pi2; |
| 421 | int delta = degree( f ) - degree( g ); |
| 422 | |
| 423 | if ( delta >= 0 ) |
| 424 | { |
| 425 | pi = f; pi1 = g; |
| 426 | } |
| 427 | else |
| 428 | { |
| 429 | pi = g; pi1 = f; delta = -delta; |
| 430 | } |
| 431 | Ci = content( pi ); Ci1 = content( pi1 ); |
| 432 | pi1 = pi1 / Ci1; pi = pi / Ci; |
| 433 | C = gcd( Ci, Ci1 ); |
| 434 | int d= 0; |
| 435 | if ( pi.isUnivariate() && pi1.isUnivariate() ) |
| 436 | { |
| 437 | #ifdef HAVE_FLINT |
| 438 | if (isPurePoly(pi) && isPurePoly(pi1) ) |
| 439 | return gcd_univar_flint0(pi, pi1 ) * C; |
| 440 | #else |
| 441 | #ifdef HAVE_NTL |
| 442 | if ( isPurePoly(pi) && isPurePoly(pi1) ) |
| 443 | return gcd_univar_ntl0(pi, pi1 ) * C; |
| 444 | #endif |
| 445 | #endif |
| 446 | return gcd_poly_univar0( pi, pi1, true ) * C; |
| 447 | } |
| 448 | else if ( gcd_test_one( pi1, pi, true, d ) ) |
| 449 | return C; |
| 450 | Variable v = f.mvar(); |
| 451 | Hi = power( LC( pi1, v ), delta ); |
| 452 | if ( (delta+1) % 2 ) |
| 453 | bi = 1; |
| 454 | else |
| 455 | bi = -1; |
| 456 | while ( degree( pi1, v ) > 0 ) |
| 457 | { |
| 458 | pi2 = psr( pi, pi1, v ); |
| 459 | pi2 = pi2 / bi; |
| 460 | pi = pi1; pi1 = pi2; |
| 461 | if ( degree( pi1, v ) > 0 ) |
| 462 | { |
| 463 | delta = degree( pi, v ) - degree( pi1, v ); |
| 464 | if ( (delta+1) % 2 ) |
| 465 | bi = LC( pi, v ) * power( Hi, delta ); |
| 466 | else |
| 467 | bi = -LC( pi, v ) * power( Hi, delta ); |
| 468 | Hi = power( LC( pi1, v ), delta ) / power( Hi, delta-1 ); |
| 469 | } |
| 470 | } |
| 471 | if ( degree( pi1, v ) == 0 ) |
| 472 | return C; |
| 473 | else |
no test coverage detected