* bignum.c (bary_2comp): Simplified.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41694 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

2 files changed, 11 insertions, 8 deletions

diff --git a/ChangeLog b/ChangeLog
index d8c1d0bb5e..7e5df87bf8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Sat Jun 29 22:31:59 2013  Tanaka Akira  <akr@fsij.org>
+
+	* bignum.c (bary_2comp): Simplified.
+
 Sat Jun 29 09:33:53 2013  Tanaka Akira  <akr@fsij.org>
 
 	* bignum.c (bigor_int): Return -1 if y == -1.
diff --git a/bignum.c b/bignum.c
index aab97fae42..583d324560 100644
--- a/bignum.c
+++ b/bignum.c
@@ -271,16 +271,15 @@ static int
 bary_2comp(BDIGIT *ds, size_t n)
 {
     size_t i = n;
-    BDIGIT_DBL num;
     if (!n) return 1;
     while (i--) ds[i] = BIGLO(~ds[i]);
-    i = 0; num = 1;
-    do {
-	num += ds[i];
-	ds[i++] = BIGLO(num);
-	num = BIGDN(num);
-    } while (i < n);
-    return num != 0;
+    i = 0;
+    for (i = 0; i < n; i++) {
+	ds[i] = BIGLO(ds[i]+1);
+        if (ds[i] != 0)
+            return 0;
+    }
+    return 1;
 }
 
 /* modify a bignum by 2's complement */