1berry/ruby
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

* bignum.c (bary_mulsub_1xN): New function.

Browse Source 
(bary_mul_toom3): Use bary_mulsub_1xN.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42123 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
This commit is contained in:
akr 2013-07-22 22:16:45 +00:00
parent fdb991b9a0
commit 66cc0fa4ab
2 changed files with 46 additions and 31 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
ChangeLog
View File

@ -1,3 +1,8 @@
Tue Jul 23 07:14:31 2013 Tanaka Akira <akr@fsij.org>
* bignum.c (bary_mulsub_1xN): New function.
(bary_mul_toom3): Use bary_mulsub_1xN.
Tue Jul 23 03:32:23 2013 Tanaka Akira <akr@fsij.org> Tue Jul 23 03:32:23 2013 Tanaka Akira <akr@fsij.org>
* bignum.c (KARATSUBA_BALANCED): New macro. * bignum.c (KARATSUBA_BALANCED): New macro.

72
bignum.c
View File

@ -1571,6 +1571,46 @@ bary_muladd_1xN(BDIGIT *zds, size_t zl, BDIGIT x, BDIGIT *yds, size_t yl)
return n != 0; return n != 0;
} }
static BDIGIT_DBL_SIGNED
bigdivrem_mulsub(BDIGIT *zds, size_t zn, BDIGIT x, BDIGIT *yds, size_t yn)
{
size_t i;
BDIGIT_DBL t2;
BDIGIT_DBL_SIGNED num;
assert(zn == yn + 1);
num = 0;
t2 = 0;
i = 0;
do {
BDIGIT_DBL ee;
t2 += (BDIGIT_DBL)yds[i] * x;
ee = num - BIGLO(t2);
num = (BDIGIT_DBL)zds[i] + ee;
if (ee) zds[i] = BIGLO(num);
num = BIGDN(num);
t2 = BIGDN(t2);
} while (++i < yn);
num += zds[i] - t2; /* borrow from high digit; don't update */
return num;
}
static int
bary_mulsub_1xN(BDIGIT *zds, size_t zn, BDIGIT x, BDIGIT *yds, size_t yn)
{
BDIGIT_DBL_SIGNED num;
assert(zn == yn + 1);
num = bigdivrem_mulsub(zds, zn, x, yds, yn);
zds[yn] = BIGLO(num);
if (BIGDN(num))
return 1;
return 0;
}
static void static void
bary_mul_normal(BDIGIT *zds, size_t zl, BDIGIT *xds, size_t xl, BDIGIT *yds, size_t yl) bary_mul_normal(BDIGIT *zds, size_t zl, BDIGIT *xds, size_t xl, BDIGIT *yds, size_t yl)
{ {
@ -2222,11 +2262,7 @@ bary_mul_toom3(BDIGIT *zds, size_t zn, BDIGIT *xds, size_t xn, BDIGIT *yds, size
bary_muladd_1xN(z3ds, z3n, 2, t4ds, t4n); bary_muladd_1xN(z3ds, z3n, 2, t4ds, t4n);
} }
else { else {
/* TODO: combining with next addition */ if (bary_mulsub_1xN(z3ds, z3n, 2, t4ds, t4n)) {
t1ds[t4n] = bary_small_lshift(t1ds, t4ds, t4n, 1);
t1n = t4n+1;
t1p = t4p;
if (bary_sub(z3ds, z3n, z3ds, z3n, t1ds, t1n)) {
bary_2comp(z3ds, z3n); bary_2comp(z3ds, z3n);
z3p = !z3p; z3p = !z3p;
} }
@ -5102,32 +5138,6 @@ struct big_div_struct {
volatile VALUE stop; volatile VALUE stop;
}; };
static BDIGIT_DBL_SIGNED
bigdivrem_mulsub(BDIGIT *zds, size_t zn, BDIGIT x, BDIGIT *yds, size_t yn)
{
size_t i;
BDIGIT_DBL t2;
BDIGIT_DBL_SIGNED num;
assert(zn == yn + 1);
num = 0;
t2 = 0;
i = 0;
do {
BDIGIT_DBL ee;
t2 += (BDIGIT_DBL)yds[i] * x;
ee = num - BIGLO(t2);
num = (BDIGIT_DBL)zds[i] + ee;
if (ee) zds[i] = BIGLO(num);
num = BIGDN(num);
t2 = BIGDN(t2);
} while (++i < yn);
num += zds[i] - t2; /* borrow from high digit; don't update */
return num;
}
static void * static void *
bigdivrem1(void *ptr) bigdivrem1(void *ptr)
{ {