diff options
author | akr <akr@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2013-07-21 12:13:47 +0000 |
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committer | akr <akr@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2013-07-21 12:13:47 +0000 |
commit | 5cf931d65e0fbee89b50a09e65b30207ac767884 (patch) | |
tree | 55fde40c7d78d29a463d65344032f0d496d33727 | |
parent | a2116ef2cd946302f08f70bb192bfd0b74f4837f (diff) |
* bignum.c (bary_mul): Use simple multiplication if yl is small.
(rb_cstr_to_inum): Invoke bigsq instead of bigmul0.
(bigsq): Re-implemented.
(bigmul0): Invoke bigsq if two arguments are identical.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42096 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
-rw-r--r-- | ChangeLog | 7 | ||||
-rw-r--r-- | bignum.c | 37 |
2 files changed, 36 insertions, 8 deletions
@@ -1,3 +1,10 @@ +Sun Jul 21 21:08:59 2013 Tanaka Akira <akr@fsij.org> + + * bignum.c (bary_mul): Use simple multiplication if yl is small. + (rb_cstr_to_inum): Invoke bigsq instead of bigmul0. + (bigsq): Re-implemented. + (bigmul0): Invoke bigsq if two arguments are identical. + Sun Jul 21 09:58:19 2013 Tanaka Akira <akr@fsij.org> * bignum.c (bary_mul_toom3): New function based on bigmul1_toom3. @@ -2496,7 +2496,7 @@ bary_mul_toom3_start(BDIGIT *zds, size_t zl, BDIGIT *xds, size_t xl, BDIGIT *yds static void bary_mul(BDIGIT *zds, size_t zl, BDIGIT *xds, size_t xl, BDIGIT *yds, size_t yl) { - if (xl < KARATSUBA_MUL_DIGITS) { + if (xl < KARATSUBA_MUL_DIGITS || yl < KARATSUBA_MUL_DIGITS) { if (xds == yds && xl == yl) bary_sq_fast(zds, zl, xds, xl); else @@ -3586,7 +3586,7 @@ rb_cstr_to_inum(const char *str, int base, int badcheck) MEMCPY(vds+i, uds+i, BDIGIT, num_bdigits-i); } } - powerv = bigtrunc(bigmul0(powerv, powerv)); + powerv = bigtrunc(bigsq(powerv)); tds = vds; vds = uds; uds = tds; @@ -5013,12 +5013,39 @@ rb_big_minus(VALUE x, VALUE y) static VALUE bigdivrem(VALUE, VALUE, volatile VALUE*, volatile VALUE*); static VALUE +bigsq(VALUE x) +{ + long xn, zn; + VALUE z; + BDIGIT *xds, *zds; + + xn = RBIGNUM_LEN(x); + zn = 2 * xn; + + z = bignew(zn, 1); + + xds = BDIGITS(x); + zds = BDIGITS(z); + + if (xn < KARATSUBA_MUL_DIGITS) + bary_sq_fast(zds, zn, xds, xn); + else + bary_mul(zds, zn, xds, xn, xds, xn); + + RB_GC_GUARD(x); + return z; +} + +static VALUE bigmul0(VALUE x, VALUE y) { long xn, yn, zn; VALUE z; BDIGIT *xds, *yds, *zds; + if (x == y) + return bigsq(x); + xn = RBIGNUM_LEN(x); yn = RBIGNUM_LEN(y); zn = xn + yn; @@ -5590,12 +5617,6 @@ rb_big_fdiv(VALUE x, VALUE y) return DBL2NUM(dx / dy); } -static VALUE -bigsq(VALUE x) -{ - return bigtrunc(bigmul0(x, x)); -} - /* * call-seq: * big ** exponent -> numeric |