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-rw-r--r--ChangeLog6
-rw-r--r--numeric.c22
2 files changed, 25 insertions, 3 deletions
diff --git a/ChangeLog b/ChangeLog
index 93ab99e13b..24ac3196c7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Thu Sep 14 17:21:07 2006 Yukihiro Matsumoto <matz@ruby-lang.org>
+
+ * numeric.c (fix_mul): avoid bignum multiplication as far as
+ possible. a patch from Ondrej Bilka <neleai at seznam.cz>.
+ [ruby-core:08825]
+
Thu Sep 14 16:34:55 2006 Yukihiro Matsumoto <matz@ruby-lang.org>
* string.c (rb_str_intern): allow zero length symbols.
diff --git a/numeric.c b/numeric.c
index d5829d14a3..5014840cdb 100644
--- a/numeric.c
+++ b/numeric.c
@@ -1973,20 +1973,36 @@ fix_mul(VALUE x, VALUE y)
/* avoids an optimization bug of HP aC++/ANSI C B3910B A.06.05 [Jul 25 2005] */
volatile
#endif
- long a, b, c;
+ SIGNED_VALUE a, b;
+#if SIZEOF_VALUE * 2 <= SIZEOF_LONG_LONG
+ LONG_LONG d;
+#else
+ SIGNED_VALUE c;
VALUE r;
+#endif
a = FIX2LONG(x);
- if (a == 0) return x;
-
b = FIX2LONG(y);
+
+#if SIZEOF_VALUE * 2 <= SIZEOF_LONG_LONG
+ d = (LONG_LONG)a * b;
+ if (FIXABLE(d)) return LONG2FIX(d);
+ return rb_ll2inum(d);
+#else
+# define SQRT_LONG_MAX (1<<((SIZEOF_VALUE*CHAR_BIT-1)/2))
+ /*tests if N*N would overflow*/
+# define FIT_SQRT_LONG(n) (((n)<SQRT_LONG_MAX)&&((N)>=-SQRT_LONG_MAX))
+ if (FIT_SQRT_LONG(a) && FIT_SQRT_LONG(b))
+ return LONG2FIX(a*b);
c = a * b;
r = LONG2FIX(c);
+ if (a == 0) return x;
if (FIX2LONG(r) != c || c/a != b) {
r = rb_big_mul(rb_int2big(a), rb_int2big(b));
}
return r;
+#endif
}
switch (TYPE(y)) {
case T_BIGNUM: