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author | akr <akr@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2013-07-28 15:14:20 +0000 |
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committer | akr <akr@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2013-07-28 15:14:20 +0000 |
commit | 7a9aeb33dba8d060c60b2bd690172fb7593865d2 (patch) | |
tree | f146c48d1297e233cfceead19557ebb8e998c66f /bignum.c | |
parent | e4b0852ae46cebab275acb0105332a115e855359 (diff) | |
download | ruby-7a9aeb33dba8d060c60b2bd690172fb7593865d2.tar.gz |
* bignum.c (bigdivrem): Specialized implementation added for
nx == 2 && ny == 2
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42218 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'bignum.c')
-rw-r--r-- | bignum.c | 21 |
1 files changed, 21 insertions, 0 deletions
@@ -5399,6 +5399,27 @@ bigdivrem(VALUE x, VALUE y, volatile VALUE *divp, volatile VALUE *modp) if (divp) *divp = z; return Qnil; } + if (nx == 2 && ny == 2) { + BDIGIT_DBL x0 = xds[0] | BIGUP(xds[1]); + BDIGIT_DBL y0 = yds[0] | BIGUP(yds[1]); + BDIGIT_DBL q0 = x0 / y0; + BDIGIT_DBL r0 = x0 % y0; + if (divp) { + z = bignew(bdigit_roomof(sizeof(BDIGIT_DBL)), RBIGNUM_SIGN(x)==RBIGNUM_SIGN(y)); + zds = BDIGITS(z); + zds[0] = BIGLO(q0); + zds[1] = BIGLO(BIGDN(q0)); + *divp = z; + } + if (modp) { + z = bignew(bdigit_roomof(sizeof(BDIGIT_DBL)), RBIGNUM_SIGN(x)); + zds = BDIGITS(z); + zds[0] = BIGLO(r0); + zds[1] = BIGLO(BIGDN(r0)); + *modp = z; + } + return Qnil; + } if (BDIGIT_MSB(yds[ny-1]) == 0) { /* Make yds modifiable. */ |