time.c: Improve Time#to_i performance

Time#to_i will be faster around 80% (on 64-bit platforms).

* Before
       user     system      total        real
   2.840000   0.000000   2.840000 (  2.847238)

* After
       user     system      total        real
   1.600000   0.000000   1.600000 (  1.598911)

* Test code
require 'benchmark'

Benchmark.bmbm do |x|
  x.report do
    t = Time.now
    20000000.times do
      t.to_i
    end
  end
end

* time.c (_div): new function avoid rb_funcall
  (div): replace with new _div function
  [ruby-core:80636] [Bug #13418]
  Thanks to Watson <watson1978@gmail.com> for the patch.

From: Watson <watson1978@gmail.com>

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58308 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 11 insertions, 1 deletions

diff --git a/time.c b/time.c
index 0d93ec65ff..04c111a0c6 100644
--- a/time.c
+++ b/time.c
@@ -103,7 +103,17 @@ mul(VALUE x, VALUE y)
     return rb_funcall(x, '*', 1, y);
 }
 
-#define div(x,y) (rb_funcall((x), id_div, 1, (y)))
+static VALUE
+_div(VALUE x, VALUE y)
+{
+    if (FIXNUM_P(x) && FIXNUM_P(y)) {
+	return rb_fix_div_fix(x, y);
+    }
+    if (RB_TYPE_P(x, T_BIGNUM))
+        return rb_big_div(x, y);
+    return rb_funcall(x, id_div, 1, y);
+}
+#define div(x,y) _div(x,y)
 
 static VALUE
 mod(VALUE x, VALUE y)