complex.c: Optimize Complex#* and Complex#**

Optimize f_mul for the core numeric class components.
This change improves the computation time of Complex#* and Complex#**.

```
$ make benchmark ITEM=complex_float_ COMPARE_RUBY=/Users/mrkn/.rbenv/versions/2.6.0/bin/ruby
generating known_errors.inc
known_errors.inc unchanged
/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/2.6.0/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       6.558M     13.012M i/s -      1.000M times in 0.152480s 0.076850s
   complex_float_div     576.821k    567.969k i/s -      1.000M times in 1.733640s 1.760660s
   complex_float_mul       1.690M      2.628M i/s -      1.000M times in 0.591786s 0.380579s
   complex_float_new       1.350M      1.268M i/s -      1.000M times in 0.740669s 0.788762s
 complex_float_power       1.571M      1.835M i/s -      1.000M times in 0.636507s 0.544909s
   complex_float_sub       8.635M      8.779M i/s -      1.000M times in 0.115814s 0.113906s

Comparison:
                complex_float_add
          built-ruby:  13012361.7 i/s
        compare-ruby:   6558237.1 i/s - 1.98x  slower

                complex_float_div
        compare-ruby:    576821.0 i/s
          built-ruby:    567968.8 i/s - 1.02x  slower

                complex_float_mul
          built-ruby:   2627575.4 i/s
        compare-ruby:   1689800.0 i/s - 1.55x  slower

                complex_float_new
        compare-ruby:   1350130.8 i/s
          built-ruby:   1267809.6 i/s - 1.06x  slower

              complex_float_power
          built-ruby:   1835168.8 i/s
        compare-ruby:   1571074.6 i/s - 1.17x  slower

                complex_float_sub
          built-ruby:   8779168.8 i/s
        compare-ruby:   8634534.7 i/s - 1.02x  slower
```

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66697 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 11 insertions, 0 deletions

diff --git a/complex.c b/complex.c
index c357c99ea5..8c7f007b44 100644
--- a/complex.c
+++ b/complex.c
@@ -131,6 +131,17 @@ f_mul(VALUE x, VALUE y)
             return ZERO;
         if (x == ONE) return y;
         if (y == ONE) return x;
+        return rb_int_mul(x, y);
+    }
+    else if (RB_FLOAT_TYPE_P(x) &&
+             UNLIKELY(rb_method_basic_definition_p(rb_cFloat, idMULT))) {
+        if (y == ONE) return x;
+        return rb_float_mul(x, y);
+    }
+    else if (RB_TYPE_P(x, T_RATIONAL) &&
+             UNLIKELY(rb_method_basic_definition_p(rb_cRational, idMULT))) {
+        if (y == ONE) return x;
+        return rb_rational_mul(x, y);
     }
     else if (UNLIKELY(rb_method_basic_definition_p(CLASS_OF(x), idMULT))) {
         if (y == ONE) return x;