complex.c: Optimize Complex#+ for some conditions

Optimize f_add defined in complex.c for some specific conditions.
It makes Complex#+ about 1.4x faster than r66678.

Compared to r66678:

```
mrkn-mbp15-late2016:complex-optim-o3 mrkn$ make benchmark ITEM=complex_float_ COMPARE_RUBY=/Users/mrkn/.rbenv/versions/trunk-o3/bin/ruby
/Users/mrkn/src/github.com/ruby/ruby/revision.h unchanged
/Users/mrkn/.rbenv/shims/ruby --disable=gems -rrubygems -I/Users/mrkn/src/github.com/ruby/ruby/benchmark/lib /Users/mrkn/src/github.com/ruby/ruby/benchmark/benchmark-driver/exe/benchmark-driver \
                    --executables="compare-ruby::/Users/mrkn/.rbenv/versions/trunk-o3/bin/ruby -I.ext/common --disable-gem" \
                    --executables="built-ruby::./miniruby -I/Users/mrkn/src/github.com/ruby/ruby/lib -I. -I.ext/common  -r/Users/mrkn/src/github.com/ruby/ruby/prelude --disable-gem" \
                    $(find /Users/mrkn/src/github.com/ruby/ruby/benchmark -maxdepth 1 -name '*complex_float_*.yml' -o -name '*complex_float_*.rb' | sort)
Calculating -------------------------------------
                     compare-ruby  built-ruby
   complex_float_add       9.132M     12.864M i/s -      1.000M times in 0.109511s 0.077734s
   complex_float_div     600.723k    627.878k i/s -      1.000M times in 1.664662s 1.592666s
   complex_float_mul       2.320M      2.347M i/s -      1.000M times in 0.431039s 0.426113s
   complex_float_new       1.473M      1.489M i/s -      1.000M times in 0.678791s 0.671750s
 complex_float_power       1.690M      1.722M i/s -      1.000M times in 0.591863s 0.580775s
   complex_float_sub       8.870M      9.516M i/s -      1.000M times in 0.112740s 0.105091s

Comparison:
                complex_float_add
          built-ruby:  12864383.7 i/s
        compare-ruby:   9131502.8 i/s - 1.41x  slower

                complex_float_div
          built-ruby:    627878.0 i/s
        compare-ruby:    600722.5 i/s - 1.05x  slower

                complex_float_mul
          built-ruby:   2346795.3 i/s
        compare-ruby:   2319975.7 i/s - 1.01x  slower

                complex_float_new
          built-ruby:   1488649.1 i/s
        compare-ruby:   1473207.5 i/s - 1.01x  slower

              complex_float_power
          built-ruby:   1721837.2 i/s
        compare-ruby:   1689580.2 i/s - 1.02x  slower

                complex_float_sub
          built-ruby:   9515562.7 i/s
        compare-ruby:   8869966.3 i/s - 1.07x  slower
```

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66681 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 14 insertions, 0 deletions

diff --git a/complex.c b/complex.c
index 38a1907aac..c4d4f80848 100644
--- a/complex.c
+++ b/complex.c
@@ -75,6 +75,20 @@ f_add(VALUE x, VALUE y)
 	return x;
     if (FIXNUM_ZERO_P(x))
 	return y;
+
+    if (RB_INTEGER_TYPE_P(x) &&
+        UNLIKELY(rb_method_basic_definition_p(rb_cInteger, idPLUS))) {
+      return rb_int_plus(x, y);
+    }
+    else if (RB_FLOAT_TYPE_P(x) &&
+             UNLIKELY(rb_method_basic_definition_p(rb_cFloat, idPLUS))) {
+      return rb_float_plus(x, y);
+    }
+    else if (RB_TYPE_P(x, T_RATIONAL) &&
+             UNLIKELY(rb_method_basic_definition_p(rb_cRational, idPLUS))) {
+      return rb_rational_plus(x, y);
+    }
+
     return rb_funcall(x, '+', 1, y);
 }