diff options
| -rw-r--r-- | ChangeLog | 7 | ||||
| -rw-r--r-- | bignum.c | 20 |
2 files changed, 20 insertions, 7 deletions
@@ -1,3 +1,10 @@ +Fri Aug 16 10:07:59 2013 Tanaka Akira <akr@fsij.org> + + * bignum.c (bigdivrem_single1): Renamed from bigdivrem_single. Add + x_higher_bdigit argument. + (bigdivrem_single): Just call bigdivrem_single1. + (bigdivrem_restoring): Use bigdivrem_single1 to avoid memmove. + Fri Aug 16 09:17:00 2013 Tanaka Akira <akr@fsij.org> * bignum.c (bary_small_rshift): Specify the higher BDIGIT instead of @@ -2677,19 +2677,20 @@ bigdivrem_num_extra_words(size_t xn, size_t yn) } static BDIGIT -bigdivrem_single(BDIGIT *qds, const BDIGIT *xds, size_t xn, BDIGIT y) +bigdivrem_single1(BDIGIT *qds, const BDIGIT *xds, size_t xn, BDIGIT x_higher_bdigit, BDIGIT y) { assert(0 < xn); + assert(x_higher_bdigit < y); if (POW2_P(y)) { BDIGIT r; r = xds[0] & (y-1); - bary_small_rshift(qds, xds, xn, bitsize(y)-1, 0); + bary_small_rshift(qds, xds, xn, bitsize(y)-1, x_higher_bdigit); return r; } else { size_t i; BDIGIT_DBL t2; - t2 = 0; + t2 = x_higher_bdigit; i = xn; while (i--) { t2 = BIGUP(t2) + xds[i]; @@ -2700,6 +2701,12 @@ bigdivrem_single(BDIGIT *qds, const BDIGIT *xds, size_t xn, BDIGIT y) } } +static BDIGIT +bigdivrem_single(BDIGIT *qds, const BDIGIT *xds, size_t xn, BDIGIT y) +{ + return bigdivrem_single1(qds, xds, xn, 0, y); +} + static void bigdivrem_restoring(BDIGIT *zds, size_t zn, BDIGIT *yds, size_t yn) { @@ -2707,15 +2714,14 @@ bigdivrem_restoring(BDIGIT *zds, size_t zn, BDIGIT *yds, size_t yn) size_t ynzero; assert(BDIGIT_MSB(yds[yn-1])); + assert(zds[zn-1] < yds[yn-1]); for (ynzero = 0; !yds[ynzero]; ynzero++); if (ynzero+1 == yn) { BDIGIT r; - r = bigdivrem_single(zds+ynzero, zds+ynzero, zn-ynzero, yds[yn-1]); - assert(zds[zn-1] == 0); - MEMMOVE(zds+yn, zds+yn-1, BDIGIT, zn - yn); - zds[yn-1] = r; + r = bigdivrem_single1(zds+yn, zds+ynzero, zn-yn, zds[zn-1], yds[ynzero]); + zds[ynzero] = r; return; } |