* rational.c: Include gmp.h if GMP is used.

(GMP_GCD_DIGITS): New macro.
  (rb_gcd_gmp): New function.
  (f_gcd_normal): Renamed from f_gcd.
  (rb_gcd_normal): New function.
  (f_gcd): Invoke rb_gcd_gmp or f_gcd_normal.

* internal.h (rb_gcd_normal): Declared.
  (rb_gcd_gmp): Ditto.

* ext/-test-/rational: New directory.




git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42858 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,19 @@
+Fri Sep  6 21:04:10 2013  Tanaka Akira  <akr@fsij.org>
+
+	* rational.c: Include gmp.h if GMP is used.
+	  (GMP_GCD_DIGITS): New macro.
+	  (rb_gcd_gmp): New function.
+	  (f_gcd_normal): Renamed from f_gcd.
+	  (rb_gcd_normal): New function.
+	  (f_gcd): Invoke rb_gcd_gmp or f_gcd_normal.
+
+	* internal.h (rb_gcd_normal): Declared.
+	  (rb_gcd_gmp): Ditto.
+
+	* ext/-test-/rational: New directory.
+
+	* test/-ext-/rational: New directory.
+
 Fri Sep  6 14:23:22 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* win32/win32.c (clock_getres): required as well as clock_gettime().

ext/-test-/rational/depend

@@ -0,0 +1,3 @@
+$(OBJS): $(HDRS) $(ruby_headers)
+
+rat.o: rat.c $(top_srcdir)/internal.h

ext/-test-/rational/extconf.rb

@@ -0,0 +1,7 @@
+$INCFLAGS << " -I$(topdir) -I$(top_srcdir)"
+$srcs = Dir[File.join($srcdir, "*.{#{SRC_EXT.join(%q{,})}}")]
+inits = $srcs.map {|s| File.basename(s, ".*")}
+inits.delete("init")
+inits.map! {|s|"X(#{s})"}
+$defs << "-DTEST_INIT_FUNCS(X)=\"#{inits.join(' ')}\""
+create_makefile("-test-/rational")

ext/-test-/rational/rat.c

@@ -0,0 +1,36 @@
+#include "ruby.h"
+#include "internal.h"
+
+static VALUE
+big(VALUE x)
+{
+    if (FIXNUM_P(x))
+        return rb_int2big(FIX2LONG(x));
+    if (RB_TYPE_P(x, T_BIGNUM))
+        return x;
+    rb_raise(rb_eTypeError, "can't convert %s to Bignum",
+            rb_obj_classname(x));
+}
+
+static VALUE
+gcd_normal(VALUE x, VALUE y)
+{
+    return rb_big_norm(rb_gcd_normal(rb_to_int(x), rb_to_int(y)));
+}
+
+#if defined(HAVE_LIBGMP) && defined(HAVE_GMP_H)
+static VALUE
+gcd_gmp(VALUE x, VALUE y)
+{
+    return rb_big_norm(rb_gcd_gmp(big(x), big(y)));
+}
+#else
+#define gcd_gmp rb_f_notimplement
+#endif
+
+void
+Init_rational(VALUE klass)
+{
+    rb_define_method(rb_cInteger, "gcd_normal", gcd_normal, 1);
+    rb_define_method(rb_cInteger, "gcd_gmp", gcd_gmp, 1);
+}

internal.h

@@ -733,6 +733,12 @@ int rb_execarg_run_options(const struct rb_execarg *e, struct rb_execarg *s, cha
 VALUE rb_execarg_extract_options(VALUE execarg_obj, VALUE opthash);
 void rb_execarg_setenv(VALUE execarg_obj, VALUE env);
 
+/* rational.c */
+VALUE rb_gcd_normal(VALUE self, VALUE other);
+#if defined(HAVE_LIBGMP) && defined(HAVE_GMP_H)
+VALUE rb_gcd_gmp(VALUE x, VALUE y);
+#endif
+
 /* util.c */
 extern const signed char ruby_digit36_to_number_table[];
 

rational.c

@@ -17,10 +17,17 @@
 #define NDEBUG
 #include <assert.h>
 
+#if defined(HAVE_LIBGMP) && defined(HAVE_GMP_H)
+#define USE_GMP
+#include <gmp.h>
+#endif
+
 #define ZERO INT2FIX(0)
 #define ONE INT2FIX(1)
 #define TWO INT2FIX(2)
 
+#define GMP_GCD_DIGITS 1
+
 VALUE rb_cRational;
 
 static ID id_abs, id_cmp, id_convert, id_eqeq_p, id_expt, id_fdiv,
@@ -276,6 +283,32 @@ k_rational_p(VALUE x)
 #define k_exact_zero_p(x) (k_exact_p(x) && f_zero_p(x))
 #define k_exact_one_p(x) (k_exact_p(x) && f_one_p(x))
 
+#ifdef USE_GMP
+VALUE
+rb_gcd_gmp(VALUE x, VALUE y)
+{
+    const size_t nails = (sizeof(BDIGIT)-SIZEOF_BDIGITS)*CHAR_BIT;
+    mpz_t mx, my, mz;
+    size_t count;
+    VALUE z;
+    long zn;
+
+    mpz_init(mx);
+    mpz_init(my);
+    mpz_init(mz);
+    mpz_import(mx, RBIGNUM_LEN(x), -1, sizeof(BDIGIT), 0, nails, RBIGNUM_DIGITS(x));
+    mpz_import(my, RBIGNUM_LEN(y), -1, sizeof(BDIGIT), 0, nails, RBIGNUM_DIGITS(y));
+
+    mpz_gcd(mz, mx, my);
+
+    zn = (mpz_sizeinbase(mz, 16) + SIZEOF_BDIGITS*2 - 1) / (SIZEOF_BDIGITS*2);
+    z = rb_big_new(zn, 1);
+    mpz_export(RBIGNUM_DIGITS(z), &count, -1, sizeof(BDIGIT), 0, nails, mz);
+
+    return rb_big_norm(z);
+}
+#endif
+
 #ifndef NDEBUG
 #define f_gcd f_gcd_orig
 #endif
@@ -302,7 +335,7 @@ i_gcd(long x, long y)
 }
 
 inline static VALUE
-f_gcd(VALUE x, VALUE y)
+f_gcd_normal(VALUE x, VALUE y)
 {
     VALUE z;
 
@@ -333,6 +366,26 @@ f_gcd(VALUE x, VALUE y)
     /* NOTREACHED */
 }
 
+VALUE
+rb_gcd_normal(VALUE x, VALUE y)
+{
+    return f_gcd_normal(x, y);
+}
+
+inline static VALUE
+f_gcd(VALUE x, VALUE y)
+{
+#ifdef USE_GMP
+    if (TYPE(x) == T_BIGNUM && TYPE(y) == T_BIGNUM) {
+        long xn = RBIGNUM_LEN(x);
+        long yn = RBIGNUM_LEN(y);
+        if (GMP_GCD_DIGITS <= xn && GMP_GCD_DIGITS <= yn)
+            return rb_gcd_gmp(x, y);
+    }
+#endif
+    return f_gcd_normal(x, y);
+}
+
 #ifndef NDEBUG
 #undef f_gcd
 

test/-ext-/rational/test_rat.rb

@@ -0,0 +1,31 @@
+require 'test/unit'
+require "-test-/rational"
+
+class TestRational < Test::Unit::TestCase
+  class TestGCD < Test::Unit::TestCase
+
+    def test_gcd_normal
+      x = 2*2*3*3*3
+      y = 2*2*2*3*3
+      gcd = 2*2*3*3
+      assert_equal(gcd, x.gcd_normal(y))
+    end
+
+    def test_gcd_gmp
+      x = 2*2*3*3*3
+      y = 2*2*2*3*3
+      gcd = 2*2*3*3
+      assert_equal(gcd, x.gcd_gmp(y))
+    rescue NotImplementedError
+    end
+
+    def test_gcd_gmp_brute_force
+      -13.upto(13) {|x|
+        -13.upto(13) {|y|
+          assert_equal(x.gcd_normal(y), x.gcd_gmp(y))
+        }
+      }
+    rescue NotImplementedError
+    end
+  end
+end