diff options
author | shyouhei <shyouhei@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2007-08-22 01:26:39 +0000 |
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committer | shyouhei <shyouhei@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2007-08-22 01:26:39 +0000 |
commit | d1992916e05993b671e9ee9a92e0bb325aadf27a (patch) | |
tree | 7054f51faa8d49640df2edcf588270365b67ef22 | |
parent | c467fe9efbd1fddffb8ef3ee5e70a127ec19b21e (diff) |
* numeric.c (fix_pow): integer power calculation: 0**n => 0,
1**n => 1, -1**n => 1 (n: even) / -1 (n: odd).
* test/ruby/test_fixnum.rb (TestFixnum::test_pow): update test
suite. pow(-3, 2^64) gives NaN when pow(3, 2^64) gives Inf.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_8_6@13182 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
-rw-r--r-- | ChangeLog | 8 | ||||
-rw-r--r-- | numeric.c | 41 | ||||
-rw-r--r-- | version.h | 2 |
3 files changed, 45 insertions, 6 deletions
@@ -1,3 +1,11 @@ +Wed Aug 22 10:24:00 2007 Yukihiro Matsumoto <matz@ruby-lang.org> + + * numeric.c (fix_pow): integer power calculation: 0**n => 0, + 1**n => 1, -1**n => 1 (n: even) / -1 (n: odd). + + * test/ruby/test_fixnum.rb (TestFixnum::test_pow): update test + suite. pow(-3, 2^64) gives NaN when pow(3, 2^64) gives Inf. + Wed Aug 22 10:23:01 2007 Yukihiro Matsumoto <matz@ruby-lang.org> * lib/base64.rb (Base64::b64encode): should not specify /o option @@ -2177,6 +2177,15 @@ fix_divmod(x, y) return rb_num_coerce_bin(x, y); } +static VALUE +int_even_p(VALUE num) +{ + if (rb_funcall(num, '%', 1, INT2FIX(2)) == INT2FIX(0)) { + return Qtrue; + } + return Qfalse; +} + /* * call-seq: * fix ** other => Numeric @@ -2193,23 +2202,45 @@ static VALUE fix_pow(x, y) VALUE x, y; { + long a = FIX2LONG(x); + if (FIXNUM_P(y)) { - long a, b; + long b; b = FIX2LONG(y); if (b == 0) return INT2FIX(1); if (b == 1) return x; a = FIX2LONG(x); if (a == 0) return INT2FIX(0); + if (a == 1) return INT2FIX(1); + if (a == -1) { + if (b % 2 == 0) + return INT2FIX(1); + else + return INT2FIX(-1); + } if (b > 0) { return rb_big_pow(rb_int2big(a), y); } return rb_float_new(pow((double)a, (double)b)); - } else if (TYPE(y) == T_FLOAT) { - long a = FIX2LONG(x); - return rb_float_new(pow((double)a, RFLOAT(y)->value)); } - return rb_num_coerce_bin(x, y); + switch (TYPE(y)) { + case T_BIGNUM: + if (a == 0) return INT2FIX(0); + if (a == 1) return INT2FIX(1); + if (a == -1) { + if (int_even_p(y)) return INT2FIX(1); + else return INT2FIX(-1); + } + x = rb_int2big(FIX2LONG(x)); + return rb_big_pow(x, y); + case T_FLOAT: + if (a == 0) return rb_float_new(0.0); + if (a == 1) return rb_float_new(1.0); + return rb_float_new(pow((double)a, RFLOAT(y)->value)); + default: + return rb_num_coerce_bin(x, y); + } } /* @@ -2,7 +2,7 @@ #define RUBY_RELEASE_DATE "2007-08-22" #define RUBY_VERSION_CODE 186 #define RUBY_RELEASE_CODE 20070822 -#define RUBY_PATCHLEVEL 67 +#define RUBY_PATCHLEVEL 68 #define RUBY_VERSION_MAJOR 1 #define RUBY_VERSION_MINOR 8 |