* internal.h (rb_big_mul_normal): Declared.

  (rb_big_mul_balance): Ditto.
  (rb_big_mul_karatsuba): Ditto.

* bignum.c (rb_big_mul_normal): New function for tests.
  (rb_big_mul_balance): Ditto.
  (rb_big_mul_karatsuba): Ditto.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41824 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 37 insertions, 0 deletions

diff --git a/bignum.c b/bignum.c
index ea828ff859..31d35b2d78 100644
--- a/bignum.c
+++ b/bignum.c
@@ -1489,6 +1489,17 @@ bary_mul_normal(BDIGIT *zds, size_t zl, BDIGIT *xds, size_t xl, BDIGIT *yds, siz
     }
 }
 
+VALUE
+rb_big_mul_normal(VALUE x, VALUE y)
+{
+    size_t xn = RBIGNUM_LEN(x), yn = RBIGNUM_LEN(y), zn = xn + yn;
+    VALUE z = bignew(zn, RBIGNUM_SIGN(x)==RBIGNUM_SIGN(y));
+    bary_mul_normal(BDIGITS(z), zn, BDIGITS(x), xn, BDIGITS(y), yn);
+    RB_GC_GUARD(x);
+    RB_GC_GUARD(y);
+    return z;
+}
+
 /* efficient squaring (2 times faster than normal multiplication)
  * ref: Handbook of Applied Cryptography, Algorithm 14.16
  *      http://www.cacr.math.uwaterloo.ca/hac/about/chap14.pdf
@@ -1558,6 +1569,19 @@ bary_mul_balance(BDIGIT *zds, size_t zl, BDIGIT *xds, size_t xl, BDIGIT *yds, si
         ALLOCV_END(work);
 }
 
+VALUE
+rb_big_mul_balance(VALUE x, VALUE y)
+{
+    size_t xn = RBIGNUM_LEN(x), yn = RBIGNUM_LEN(y), zn = xn + yn;
+    VALUE z = bignew(zn, RBIGNUM_SIGN(x)==RBIGNUM_SIGN(y));
+    if (!(2 * xn <= yn || 3 * xn <= 2*(yn+2)))
+        rb_raise(rb_eArgError, "invalid bignum length");
+    bary_mul_balance(BDIGITS(z), zn, BDIGITS(x), xn, BDIGITS(y), yn);
+    RB_GC_GUARD(x);
+    RB_GC_GUARD(y);
+    return z;
+}
+
 /* multiplication by karatsuba method */
 static void
 bary_mul_karatsuba(BDIGIT *zds, size_t zl, BDIGIT *xds, size_t xl, BDIGIT *yds, size_t yl)
@@ -1720,6 +1744,19 @@ bary_mul_karatsuba(BDIGIT *zds, size_t zl, BDIGIT *xds, size_t xl, BDIGIT *yds,
         ALLOCV_END(work);
 }
 
+VALUE
+rb_big_mul_karatsuba(VALUE x, VALUE y)
+{
+    size_t xn = RBIGNUM_LEN(x), yn = RBIGNUM_LEN(y), zn = xn + yn;
+    VALUE z = bignew(zn, RBIGNUM_SIGN(x)==RBIGNUM_SIGN(y));
+    if (!(xn <= yn && yn < 2 * xn))
+        rb_raise(rb_eArgError, "invalid bignum length");
+    bary_mul_karatsuba(BDIGITS(z), zn, BDIGITS(x), xn, BDIGITS(y), yn);
+    RB_GC_GUARD(x);
+    RB_GC_GUARD(y);
+    return z;
+}
+
 static void
 bary_mul1(BDIGIT *zds, size_t zl, BDIGIT *xds, size_t xl, BDIGIT *yds, size_t yl)
 {