diff options
| author | usa <usa@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2012-11-09 04:16:27 +0000 |
|---|---|---|
| committer | usa <usa@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2012-11-09 04:16:27 +0000 |
| commit | 995e42817c01111bc3dfeb092d3ed7e080edd8c2 (patch) | |
| tree | 414972ec9c922d0bbb1bd4a9d813de7941a9ff17 /bignum.c | |
| parent | 122b6dbcb7c7c5e3c02277d75b5f38bc6d5c3103 (diff) | |
merge revision(s) 37567: [Backport #7315]
* bignum.c (bigmul0): enable big_mul_toom3.
[ruby-core:48552] [Bug #7242]
* bignum.c (bigmul1_toom3): fix incorrect calculation.
the patch is made by Heesob Park.
[ruby-core:48552] [Bug #7242]
* bignum.c (bigmul0): disable big_mul_toom3 temporalily.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_3@37573 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'bignum.c')
| -rw-r--r-- | bignum.c | 11 |
1 files changed, 8 insertions, 3 deletions
@@ -2419,7 +2419,7 @@ bigmul1_toom3(VALUE x, VALUE y) z2 = bigtrunc(bigadd(u2, u0, 0)); /* z3 <- (z2 - z3) / 2 + 2 * z(inf) == (z2 - z3) / 2 + 2 * u4 */ - z3 = bigadd(z2, z3, 0); + z3 = bigtrunc(bigadd(z2, z3, 0)); bigrsh_bang(BDIGITS(z3), RBIGNUM_LEN(z3), 1); t = big_lshift(u4, 1); /* TODO: combining with next addition */ z3 = bigtrunc(bigadd(z3, t, 1)); @@ -2535,8 +2535,13 @@ bigmul0(VALUE x, VALUE y) /* balance multiplication by slicing y when x is much smaller than y */ if (2 * xn <= yn) return bigmul1_balance(x, y); - /* multiplication by karatsuba method */ - return bigmul1_karatsuba(x, y); + if (xn < TOOM3_MUL_DIGITS) { + /* multiplication by karatsuba method */ + return bigmul1_karatsuba(x, y); + } + else if (3*xn <= 2*(yn + 2)) + return bigmul1_balance(x, y); + return bigmul1_toom3(x, y); } /* |