* numeric.c (int_pow, fix_mul): Avoid optimization bugs of

  clang.  Submitted by Wataru Kimura [Bug #6796].


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_8@36546 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

2 files changed, 9 insertions, 4 deletions

diff --git a/ChangeLog b/ChangeLog
index a7d903f4b5..ec3b8335e1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Fri Jul 27 13:04:31 2012  Akinori MUSHA  <knu@iDaemons.org>
+
+	* numeric.c (int_pow, fix_mul): Avoid optimization bugs of
+	  clang.  Submitted by Wataru Kimura [Bug #6796].
+
 Fri Jun 29 21:19:36 2012  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* eval.c (stack_extend): prevent ALLOCA_N, which reserves a memory
diff --git a/numeric.c b/numeric.c
index 707adbf624..cdb047c110 100644
--- a/numeric.c
+++ b/numeric.c
@@ -2162,7 +2162,7 @@ fix_mul(x, y)
     VALUE x, y;
 {
     if (FIXNUM_P(y)) {
-#ifdef __HP_cc
+#if defined(__HP_cc) || defined(__clang__)
         /* avoids an optimization bug of HP aC++/ANSI C B3910B A.06.05 [Jul 25 2005] */
         volatile
 #endif
@@ -2320,9 +2320,9 @@ int_pow(x, y)
     y &= ~1;
     do {
 	while (y % 2 == 0) {
-	    long x2 = x * x;
+	    volatile long x2 = x * x;
 	    if (x2/x != x || !POSFIXABLE(x2)) {
-		VALUE v;
+		volatile VALUE v;
 	      bignum:
 		v = rb_big_pow(rb_int2big(x), LONG2NUM(y));
 		if (z != 1) v = rb_big_mul(rb_int2big(neg ? -z : z), v);
@@ -2332,7 +2332,7 @@ int_pow(x, y)
 	    y >>= 1;
 	}
 	{
-	    long xz = x * z;
+	    volatile long xz = x * z;
 	    if (!POSFIXABLE(xz) || xz / x != z) {
 		goto bignum;
 	    }