diff options
| author | tege <tege@gmplib.org> | 2002-04-27 02:29:00 +0200 |
|---|---|---|
| committer | tege <tege@gmplib.org> | 2002-04-27 02:29:00 +0200 |
| commit | dcaa6bb7c9a88c99a47acec2b2dde9fd31d9e34e (patch) | |
| tree | b0efa762f3e1f1d7cad88b99dc4e94ddc564aacf /mpn | |
| parent | 7b24af576e5794c1f6328ea3bb73c2069bab3f58 (diff) | |
| download | gmp-dcaa6bb7c9a88c99a47acec2b2dde9fd31d9e34e.tar.gz | |
(div2): Remove qh paramater.
(mpn_gcdext): Streamline double-limb code.
Move GCDEXT_THRESHOLD check to after initial division.
Diffstat (limited to 'mpn')
| -rw-r--r-- | mpn/generic/gcdext.c | 41 |
1 files changed, 11 insertions, 30 deletions
diff --git a/mpn/generic/gcdext.c b/mpn/generic/gcdext.c index ff9ab7fb2..25be31ea2 100644 --- a/mpn/generic/gcdext.c +++ b/mpn/generic/gcdext.c @@ -68,17 +68,10 @@ int arr[BITS_PER_MP_LIMB + 1]; and then switch to double-limb arithmetic. */ -/* Division optimized for small quotients. If the quotient is more than one limb, - store 1 in *qh and return 0. */ +/* Two-limb division optimized for small quotients. */ static mp_limb_t -div2 (mp_limb_t *qh, mp_limb_t n1, mp_limb_t n0, mp_limb_t d1, mp_limb_t d0) +div2 (mp_limb_t n1, mp_limb_t n0, mp_limb_t d1, mp_limb_t d0) { - if (d1 == 0) - { - *qh = 1; - return 0; - } - if ((mp_limb_signed_t) n1 < 0) { mp_limb_t q; @@ -103,7 +96,6 @@ div2 (mp_limb_t *qh, mp_limb_t n1, mp_limb_t n0, mp_limb_t d1, mp_limb_t d0) cnt--; } - *qh = 0; return q; } else @@ -130,7 +122,6 @@ div2 (mp_limb_t *qh, mp_limb_t n1, mp_limb_t n0, mp_limb_t d1, mp_limb_t d0) cnt--; } - *qh = 0; return q; } } @@ -173,8 +164,6 @@ mpn_gcd (mp_ptr gp, TMP_MARK (mark); - use_double_flag = ABOVE_THRESHOLD (size, GCDEXT_THRESHOLD); - tp = (mp_ptr) TMP_ALLOC ((size + 1) * BYTES_PER_MP_LIMB); wp = (mp_ptr) TMP_ALLOC ((size + 1) * BYTES_PER_MP_LIMB); #if EXTEND @@ -204,6 +193,8 @@ mpn_gcd (mp_ptr gp, MP_PTR_SWAP (up, vp); } + use_double_flag = ABOVE_THRESHOLD (size, GCDEXT_THRESHOLD); + for (;;) { mp_limb_t asign; @@ -245,26 +236,20 @@ mpn_gcd (mp_ptr gp, for (;;) { mp_limb_t T; - mp_limb_t qh, q1, q2; + mp_limb_t q1, q2; mp_limb_t nh, nl, dh, dl; mp_limb_t t1, t0; mp_limb_t Th, Tl; sub_ddmmss (dh, dl, vh, vl, 0, C); - if ((dl | dh) == 0) + if (dh == 0) break; add_ssaaaa (nh, nl, uh, ul, 0, A); - q1 = div2 (&qh, nh, nl, dh, dl); - if (qh != 0) - break; /* could handle this */ + q1 = div2 (nh, nl, dh, dl); add_ssaaaa (dh, dl, vh, vl, 0, D); - if ((dl | dh) == 0) - break; sub_ddmmss (nh, nl, uh, ul, 0, B); - q2 = div2 (&qh, nh, nl, dh, dl); - if (qh != 0) - break; /* could handle this */ + q2 = div2 (nh, nl, dh, dl); if (q1 != q2) break; @@ -285,17 +270,13 @@ mpn_gcd (mp_ptr gp, add_ssaaaa (dh, dl, vh, vl, 0, C); sub_ddmmss (nh, nl, uh, ul, 0, A); - q1 = div2 (&qh, nh, nl, dh, dl); - if (qh != 0) - break; /* could handle this */ + q1 = div2 (nh, nl, dh, dl); sub_ddmmss (dh, dl, vh, vl, 0, D); - if ((dl | dh) == 0) + if (dh == 0) break; add_ssaaaa (nh, nl, uh, ul, 0, B); - q2 = div2 (&qh, nh, nl, dh, dl); - if (qh != 0) - break; /* could handle this */ + q2 = div2 (nh, nl, dh, dl); if (q1 != q2) break; |