* bignum.c (big2ulong): Add code specialized for SIZEOF_LONG <=

  SIZEOF_BDIGITS.
  This prevents shift witdth warning from "num <<= BITSPERDIG".



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41615 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

2 files changed, 14 insertions, 1 deletions

diff --git a/ChangeLog b/ChangeLog
index 9d194f09dc..12e0016319 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Tue Jun 25 12:28:57 2013  Tanaka Akira  <akr@fsij.org>
+
+	* bignum.c (big2ulong): Add code specialized for SIZEOF_LONG <=
+	  SIZEOF_BDIGITS.
+	  This prevents shift witdth warning from "num <<= BITSPERDIG".
+
 Tue Jun 25 12:23:30 2013  Koichi Sasada  <ko1@atdot.net>
 
 	* gc.c: fix oldgen/remembered_shady counting algorithm.
diff --git a/bignum.c b/bignum.c
index 51ae0f9d20..697d833299 100644
--- a/bignum.c
+++ b/bignum.c
@@ -2413,17 +2413,24 @@ big2ulong(VALUE x, const char *type, int check)
     unsigned long num;
     BDIGIT *ds;
 
+    if (len == 0)
+        return 0;
     if (BIGSIZE(x) > sizeof(long)) {
 	if (check)
 	    rb_raise(rb_eRangeError, "bignum too big to convert into `%s'", type);
-	len = bdigit_roomof(sizeof(long));
+        if (bdigit_roomof(sizeof(long)) < len)
+            len = bdigit_roomof(sizeof(long));
     }
     ds = BDIGITS(x);
+#if SIZEOF_LONG <= SIZEOF_BDIGITS
+    num = ds[0];
+#else
     num = 0;
     while (len--) {
 	num <<= BITSPERDIG;
 	num += (unsigned long)ds[len]; /* overflow is already checked */
     }
+#endif
     return num;
 }