From c3b656bc8eb8fede8de7c2505e1135f8d7c399f0 Mon Sep 17 00:00:00 2001
From: nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Wed, 13 Jun 2018 01:04:33 +0000
Subject: [PATCH] bignum.c: refine pow

* bignum.c (rb_big_pow): make Complex and Rational instances from
  calculated results by API functions.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63642 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 bignum.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/bignum.c b/bignum.c
index fd5f385cac..a707c2d562 100644
--- a/bignum.c
+++ b/bignum.c
@@ -6209,8 +6209,10 @@ rb_big_pow(VALUE x, VALUE y)
     if (y == INT2FIX(0)) return INT2FIX(1);
     if (RB_FLOAT_TYPE_P(y)) {
 	d = RFLOAT_VALUE(y);
-	if ((BIGNUM_NEGATIVE_P(x) && !BIGZEROP(x)) && d != round(d))
-	    return rb_funcall(rb_complex_raw1(x), idPow, 1, y);
+	if ((BIGNUM_NEGATIVE_P(x) && !BIGZEROP(x)) && d != round(d)) {
+	    x = DBL2NUM(pow(-rb_big2dbl(x),  d));
+	    return rb_complex_polar(x, DBL2NUM(d * M_PI));
+	}
     }
     else if (RB_BIGNUM_TYPE_P(y)) {
 	y = bignorm(y);
@@ -6223,7 +6225,7 @@ rb_big_pow(VALUE x, VALUE y)
 	yy = FIX2LONG(y);
 
 	if (yy < 0)
-	    return rb_funcall(rb_rational_raw1(x), idPow, 1, y);
+	    return rb_rational_raw(INT2FIX(1), rb_big_pow(x, INT2NUM(-yy)));
 	else {
 	    VALUE z = 0;
 	    SIGNED_VALUE mask;