diff options
-rw-r--r-- | ChangeLog | 6 | ||||
-rw-r--r-- | numeric.c | 11 | ||||
-rw-r--r-- | test/ruby/test_fixnum.rb | 26 |
3 files changed, 39 insertions, 4 deletions
@@ -1,3 +1,9 @@ +Thu Jul 5 16:37:34 2007 NAKAMURA Usaku <usa@ruby-lang.org> + + * numeric.c (int_pow): fix previous nubu's commit. + + * test/ruby/test_fixnum.rb: new test. + Thu Jul 5 15:56:06 2007 Nobuyoshi Nakada <nobu@ruby-lang.org> * numeric.c (int_pow): even number multiplication never be negative. @@ -2281,7 +2281,10 @@ int_pow(long x, unsigned long y) long z = 1; if (neg) x = -x; - if (y & 1) z = x; + if (y & 1) + z = x; + else + neg = 0; y &= ~1; do { while (y % 2 == 0) { @@ -2289,8 +2292,8 @@ int_pow(long x, unsigned long y) if (x2 < x || !POSFIXABLE(x2)) { VALUE v; bignum: - v = rb_big_pow(rb_int2big(neg ? -x : x), LONG2NUM(y)); - if (z != 1) v = rb_big_mul(rb_int2big(z), v); + v = rb_big_pow(rb_int2big(x), LONG2NUM(y)); + if (z != 1) v = rb_big_mul(rb_int2big(neg ? -z : z), v); return v; } x = x2; @@ -2304,7 +2307,7 @@ int_pow(long x, unsigned long y) z = xz; } } while (--y); - if (neg && (y & 1)) z = -z; + if (neg) z = -z; return LONG2NUM(z); } diff --git a/test/ruby/test_fixnum.rb b/test/ruby/test_fixnum.rb new file mode 100644 index 0000000000..57999d4b03 --- /dev/null +++ b/test/ruby/test_fixnum.rb @@ -0,0 +1,26 @@ +require 'test/unit' + +class TestFixnum < Test::Unit::TestCase + def setup + @verbose = $VERBOSE + $VERBOSE = nil + end + + def teardown + $VERBOSE = @verbose + end + + def test_pow + [1, 2, 2**64, 2**63*3, 2**64*3].each do |y| + [1, 3].each do |x| + z1 = x**y + z2 = (-x)**y + if y % 2 == 1 + assert_equal(z2, -z1) + else + assert_equal(z2, z1) + end + end + end + end +end |