diff options
| author | Marco Bodrato <bodrato@mail.dm.unipi.it> | 2022-05-29 16:16:47 +0200 |
|---|---|---|
| committer | Marco Bodrato <bodrato@mail.dm.unipi.it> | 2022-05-29 16:16:47 +0200 |
| commit | 976ee0b1d700ece99df97ba014a0b33d9ba539e7 (patch) | |
| tree | ffbaddc121418c3a4e9dc28d57186f64a14ac7d4 | |
| parent | 2229af6209d84b65e9d941f6f2a239e927a70224 (diff) | |
| download | gmp-976ee0b1d700ece99df97ba014a0b33d9ba539e7.tar.gz | |
mpz/aorsmul.c: New shortcuts for the case mpz_aorsmul(w,x,x). Tx: Fredrik Johansson
| -rw-r--r-- | mpz/aorsmul.c | 26 |
1 files changed, 21 insertions, 5 deletions
diff --git a/mpz/aorsmul.c b/mpz/aorsmul.c index 57b06b3a5..ba766f647 100644 --- a/mpz/aorsmul.c +++ b/mpz/aorsmul.c @@ -1,6 +1,6 @@ /* mpz_addmul, mpz_submul -- add or subtract multiple. -Copyright 2001, 2004, 2005, 2012 Free Software Foundation, Inc. +Copyright 2001, 2004, 2005, 2012, 2022 Free Software Foundation, Inc. This file is part of the GNU MP Library. @@ -52,7 +52,7 @@ mpz_aorsmul (mpz_ptr w, mpz_srcptr x, mpz_srcptr y, mp_size_t sub) { mp_size_t xsize, ysize, tsize, wsize, wsize_signed; mp_ptr wp, tp; - mp_limb_t c, high; + mp_limb_t c; TMP_DECL; /* w unaffected if x==0 or y==0 */ @@ -90,9 +90,16 @@ mpz_aorsmul (mpz_ptr w, mpz_srcptr x, mpz_srcptr y, mp_size_t sub) if (wsize_signed == 0) { + mp_limb_t high; /* Nothing to add to, just set w=x*y. No w==x or w==y overlap here, since we know x,y!=0 but w==0. */ - high = mpn_mul (wp, PTR(x),xsize, PTR(y),ysize); + if (x == y) + { + mpn_sqr (wp, PTR(x),xsize); + high = wp[tsize-1]; + } + else + high = mpn_mul (wp, PTR(x),xsize, PTR(y),ysize); tsize -= (high == 0); SIZ(w) = (sub >= 0 ? tsize : -tsize); return; @@ -101,8 +108,17 @@ mpz_aorsmul (mpz_ptr w, mpz_srcptr x, mpz_srcptr y, mp_size_t sub) TMP_MARK; tp = TMP_ALLOC_LIMBS (tsize); - high = mpn_mul (tp, PTR(x),xsize, PTR(y),ysize); - tsize -= (high == 0); + if (x == y) + { + mpn_sqr (tp, PTR(x),xsize); + tsize -= (tp[tsize-1] == 0); + } + else + { + mp_limb_t high; + high = mpn_mul (tp, PTR(x),xsize, PTR(y),ysize); + tsize -= (high == 0); + } ASSERT (tp[tsize-1] != 0); if (sub >= 0) { |