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authormatz <matz@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>1998-05-13 07:26:47 +0000
committermatz <matz@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>1998-05-13 07:26:47 +0000
commitae2fe781dd4aae16a2f03a4b9fb93514eb9886d4 (patch)
treebc7b2f6399af854b2b7e3515916c5f51d970bf57 /bignum.c
parentad592443af373c3bbe61b41df106734856ad3072 (diff)
1.1b9_19
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/v1_1r@209 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'bignum.c')
-rw-r--r--bignum.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/bignum.c b/bignum.c
index bd14002..cce2327 100644
--- a/bignum.c
+++ b/bignum.c
@@ -558,6 +558,18 @@ bigadd(x, y, sign)
if (RBIGNUM(y)->sign == sign) return bigsub(y, x);
return bigsub(x, y);
}
+ else if (sign == 0) {
+ /* x - y */
+ if ((RBIGNUM(x)->sign == 0) && (RBIGNUM(y)->sign == 1)) {
+ /* x is negative and y is positive. */
+ /* return -(abs(x) + y) */
+ VALUE ret;
+ RBIGNUM(x)->sign = 1; /* x = abs(x) */
+ ret = bigadd(x, y, 1); /* ret = x + y (recursive call) */
+ RBIGNUM(ret)->sign = 0; /* ret = -ret */
+ return ret;
+ }
+ }
if (RBIGNUM(x)->len > RBIGNUM(y)->len) {
len = RBIGNUM(x)->len + 1;