2 files changed, 6 insertions, 2 deletions
diff --git a/ChangeLog b/ChangeLog
index 36415fc238..de57cf78d8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sat Jun 22 13:07:15 2013  Tanaka Akira  <akr@fsij.org>
+
+	* bignum.c (CLEAR_LOWBITS): Rewritten without RSHIFTX.
+	  (RSHIFTX): Removed.
+
 Sat Jun 22 10:38:03 2013  Tanaka Akira  <akr@fsij.org>
 
 	* pack.c (num2i32): Removed.
diff --git a/bignum.c b/bignum.c
index 49af3016d7..7c78a3fbd8 100644
--- a/bignum.c
+++ b/bignum.c
@@ -40,8 +40,7 @@ static VALUE big_three = Qnil;
 #endif
 #define ALIGNOF(type) ((int)offsetof(struct { char f1; type f2; }, f2))
 #define LSHIFTX(d, n) (sizeof(d) * CHAR_BIT <= (n) ? 0 : ((d) << (sizeof(d) * CHAR_BIT <= (n) ? 0 : (n))))
-#define RSHIFTX(d, n) (sizeof(d) * CHAR_BIT <= (n) ? ~((d)*0) : RSHIFT((d), (sizeof(d) * CHAR_BIT <= (n) ? 0 : (n))))
-#define CLEAR_LOWBITS(d, numbits) LSHIFTX(RSHIFTX((d), (numbits)), (numbits))
+#define CLEAR_LOWBITS(d, numbits) ((d) & LSHIFTX(~((d)*0), (numbits)))
 #define FILL_LOWBITS(d, numbits) ((d) | (LSHIFTX(((d)*0+1), (numbits))-1))
 
 #define BDIGITS(x) (RBIGNUM_DIGITS(x))